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{{cleanup|reason = This article reads as if it is a research paper and not an encyclopedia article (in part because it is mostly cut and paste from the public domain study by NASA). It needs to be moved to a more encyclopedic topic heading, perhaps something like [[Cancer and spaceflight]], and re-written in an encyclopedia article style.|date=July 2012}}
{{expert-subject|Medicine|ex2=Spaceflight|date=July 2012}}
}}


[[File:iss002e5952.jpg|thumb|300px|The Phantom Torso, seen here in the Destiny laboratory on the International Space Station (ISS), is designed to measure the effects of radiation on organs inside the body by using a torso that is similar to those used to train radiologists on Earth. The torso is equivalent in height and weight to an average adult male. It contains radiation detectors that will measure, in real-time, how much radiation the brain, thyroid, stomach, colon, and heart and lung area receive on a daily basis. The data will be used to determine how the body reacts to and shields its internal organs from radiation, which will be important for longer duration space flights.]]


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Astronauts are exposed to approximately 50-2,000 mSv ([[Sievert|mili-Sievert]]) while on six-month-duration missions<!-- need to clarify, missions of the same duration in LEO would expect to receive much less radiation than same-duration missions to the moon which pass through the radiation belts --> to the [[International Space Station]] (ISS), the moon and beyond.<ref name="Cucinotta and Durante 2006">{{cite journal|last=Cucinotta|first=FA|coauthors=Durante, M|title=Cancer risk from exposure to galactic cosmic rays: implications for space exploration by human beings|journal=Lancet Oncol.|year=2006|volume=7|pages=431–435|doi=10.1016/S1470-2045(06)70695-7|issue=5|pmid=16648048}}</ref><ref name="Cucinotta 2008">{{cite journal|last=Cucinotta|first=FA|coauthors=Kim, MH; Willingham, V; George, KA|title=Physical and biological organ dosimetry analysis for international space station astronauts|journal=Radiation research|date=Jul 2008|volume=170|issue=1|pages=127–38|pmid=18582161|doi=10.1667/RR1330.1}}</ref>  The risk of cancer caused by [[ionizing radiation]] is well documented at radiation doses beginning at 50 mSv and above.<ref name="Cucinotta and Durante 2006" /><ref name="Durante 2008">{{cite journal|last=Durante|first=M|coauthors=Cucinotta, FA|title=Heavy ion carcinogenesis and human space exploration|journal=Nature reviews. Cancer|date=June 2008|volume=8|issue=6|pages=465–72|pmid=18451812|url=http://nix.nasa.gov/search.jsp?R=20080012531&qs=N%3D4294595076%2B4294290746|doi=10.1038/nrc2391}}</ref><ref name="BIER 2006">{{cite book|last=BIER|first=Committee to assess Health Risks from Exposure to Low levels of Ionizing Radiation|title=Health risks from exposure to low levels of ionizing radiation: BIER VII - Phase 2|year=2006|publisher=The National Academies Press|location=Washington, D.C.|url=http://www.nap.edu/openbook.php?isbn=030909156X|coauthors=National Research Council of the National Academies}}</ref>
 
Related radiological effect studies have shown that survivors of the atomic bomb explosions in [[Hiroshima]] and [[Nagasaki]], nuclear reactor workers and patients who have undergone [[Radiation therapy|therapeutic radiation treatments]] have received [http://medical-dictionary.thefreedictionary.com/linear+energy+transfer low-linear energy transfer (LET)] radiation ([[x-rays]] and [[gamma rays]]) doses in the same 50-2000 mSv range.<ref>{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=6 June 2012|coauthors=Durante, M.|page=121}}</ref>
 
==Composition of space radiation==
While in space, astronauts are exposed to [[protons]], [[helium]] nuclei, and high-Z high energy ions ([[HZE ions]]), as well as [[secondary radiation]] from nuclear reactions from spacecraft parts or tissue.<ref name=122-123 />
 
Space radiation is composed mostly of high-energy protons, helium nuclei, and HZE ions.  The ionization patterns in molecules, cells, tissues and the resulting biological insults are distinct from typical terrestrial radiation ([[x-ray]]s and [[gamma ray]]s, which are [http://medical-dictionary.thefreedictionary.com/linear+energy+transfer low-LET radiation]). [[Galactic cosmic ray|GCRs (galactic cosmic rays)]] from outside of the [[Milky Way|Milky Way galaxy]] consist mostly of highly energetic protons with a small component of HZE ions.<ref name=122-123 />
 
Prominent HZE ions:
* [[Carbon|carbon (C)]]
* [[Oxygen|oxygen (O)]]
* [[Magnesium|magnesium (Mg)]]
* [[Silicon|silicon (Si)]]
* [[Iron|iron (Fe)]]
[[Galactic cosmic ray|GCR (galactic cosmic ray)]]<ref>{{cite web|title=Galactic Cosmic Rays|url=http://helios.gsfc.nasa.gov/gcr.html|publisher=NASA|accessdate=6 June 2012}}</ref> energy spectra peaks (with median energy peaks up to 1,000 [[Electronvolt|MeV]]/amu) and nuclei (energies up to 10,000 [[Electronvolt|MeV]]/amu) are important contributors to the dose equivalent.<ref name=122-123 />
 
==Uncertainties in cancer projections==
One of the main roadblocks to interplanetary travel is the risk of cancer caused by radiation exposure. The largest contributors to this roadblock are: (1) The large uncertainties associated with cancer risk estimates, (2) The unavailability of simple and effective countermeasures and (3) The inability to determine the effectiveness of countermeasures. <br><ref name="122-123">{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=6 June 2012|coauthors=Durante, M.|pages=122–123}}</ref>
Operational parameters that need to be optimized to help mitigate these risks include:<ref name=122-123 />
* length of space missions
* crew age
* crew gender
* shielding
* biological countermeasures
 
===Major uncertainties<ref name=122-123 />===
* effects on biological damage related to differences between space radiation and x-rays
* dependence of risk on dose-rates in space related to the biology of DNA repair, cell regulation and tissue responses
* predicting solar particle events (SPEs)
* extrapolation from experimental data to humans and between human populations
* individual radiation sensitivity factors (genetic, epigenetic, dietary or "healthy worker" effects)
 
===Minor uncertainties<ref name=122-123 />===
* data on [[Galactic cosmic ray|GCR (galactic cosmic ray)]] environments
* physics of shielding assessments related to transmission properties of radiation through materials and tissue
* microgravity effects on biological responses to radiation
* errors in human data (statistical, dosimetry or recording inaccuracies)
 
Quantitative methods have been developed to propagate uncertainties that contribute to cancer risk estimates.  The contribution of microgravity effects on space radiation has not yet been estimated, but it is expected to be small.  The effects of changes in oxygen levels or in immune dysfunction on cancer risks are largely unknown and are of great concern during space flight.<ref name=122-123 />
 
==Types of cancer caused by radiation exposure==
Studies are being conducted on populations accidentally exposed to radiation ([[Chernobyl]], production sites as well as [[Hiroshima]] and [[Nagasaki]]). These studies show strong evidence for cancer morbidity as well as mortality risks at more than 12 tissue sites.  The largest risks for adults who have been studied include several types of [[leukemia]], including [[myeloid leukemia]] <ref name=126-126 /> and acute lymphatic lymphoma <ref name=126-126 /> as well as tumors of the [[Lung cancer|lung]], [[Breast cancer|breast]], [[Stomach cancer|stomach]], [[Colorectal cancer|colon]], [[Bladder cancer|bladder]] and [[Liver cancer|liver]].  Inter-gender variations are very likely due to the differences in the natural incidence of cancer in males and females.  Another variable is the additional risk for cancer of the breast, ovaries and lungs in females.<ref name="NCRP 2000">{{cite book|last=NCRP|title=NCRP Report No. 132, Radiation Protection Guidance for Activities in Low-Earth Orbit|year=2000|publisher=NCRP|location=Bethseda, Md.|url=http://www.ncrponline.org/Publications/Press_Releases/132press.html}}</ref>  There is also evidence of a declining risk of cancer caused by radiation with increasing age, but the magnitude of this reduction above the age of 30 is uncertain.<ref name=122-123 />
 
It is unknown whether high-LET radiation could cause the same types of tumors as low-LET radiation, but differences should be expected.<ref name=126-126>{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=8 June 2012|coauthors=Durante, M.|pages=126–126}}</ref>
 
The ratio of a dose of high-LET radiation to a dose of x-rays or gamma rays that produce the same biological effect are called relative biological effectiveness (BRE) factors.  The types of tumors in humans who are exposed to space radiation will be different from those who are exposed to low-LET radiation.  This is evidenced by a study that observed mice with neutrons and have RBEs that vary with the tissue type and strain.<ref name=126-126 />
 
==Approaches for Setting Acceptable Risk Levels==
The various approaches to setting acceptable levels of radiation risk are summarized below:<ref name=137-138>{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=8 June 2012|coauthors=Durante, M.|pages=137–138}}</ref>
[[File:PIA17601-Comparisons-RadiationExposure-MarsTrip-20131209.png|thumb|250px|right|Comparison of Radiation Doses - includes the amount detected on the trip from Earth to Mars by the [[Radiation assessment detector|RAD]] on the [[Mars Science Laboratory|MSL]] (2011 - 2013).<ref name="SCI-20130531a">{{cite journal |last=Kerr |first=Richard |title=Radiation Will Make Astronauts' Trip to Mars Even Riskier |url=http://www.sciencemag.org/content/340/6136/1031.summary |date=31 May 2013 |journal=[[Science (journal)|Science]] |volume=340 |page=1031 |doi=10.1126/science.340.6136.1031 |accessdate=31 May 2013 |issue=6136 }}</ref><ref name="SCI-20130531b">{{cite journal |title=Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory |url=http://www.sciencemag.org/content/340/6136/1080.abstract |journal=[[Science (journal)|Science]] |date=31 May 2013 |volume=340 |pages=1080–1084 |doi=10.1126/science.1235989 |accessdate=31 May 2013 |author=Zeitlin, C. et al. |issue=6136 |last2=Hassler |first2=D. M. |last3=Cucinotta |first3=F. A. |last4=Ehresmann |first4=B. |last5=Wimmer-Schweingruber |first5=R. F. |last6=Brinza |first6=D. E. |last7=Kang |first7=S. |last8=Weigle |first8=G. |last9=Bottcher |first9=S. }}</ref><ref name="NYT-20130530">{{cite news |last=Chang |first=Kenneth |title=Data Point to Radiation Risk for Travelers to Mars |url=http://www.nytimes.com/2013/05/31/science/space/data-show-higher-cancer-risk-for-mars-astronauts.html |date=30 May 2013 |publisher=[[New York Times]] |accessdate=31 May 2013 }}</ref><ref name="SN-20130629">{{cite journal |last=Gelling |first=Cristy|title=Mars trip would deliver big radiation dose; Curiosity instrument confirms expectation of major exposures|url=http://www.sciencenews.org/view/generic/id/350728/description/Mars_trip_would_deliver_big_radiation_dose|volume=183 |issue=13 |page=8 |journal=[[Science News]] |date=June 29, 2013 |accessdate=July 8, 2013 }}</ref> ]]
* Unlimited Radiation Risk - NASA management, the families of loved ones of astronauts, and taxpayers would find this approach unacceptable.
* Comparison to Occupational Fatalities in Less-safe Industries - The life-loss from attributable radiation cancer death is less than that from most other occupational deaths.  At this time, this comparison would also be very restrictive on ISS operations because of continued improvements in ground-based occupational safety over the last 20 years.
* Comparison to Cancer Rates in General Population - The number of years of life-loss from radiation-induced cancer deaths can be significantly larger than from cancer deaths in the general population, which often occur late in life (> age 70 years) and with significantly less numbers of years of life-loss.
* Doubling Dose for 20 Years Following Exposure - Provides a roughly equivalent comparison based on life-loss from other occupational risks or background cancer fatalities during a worker's career, however, this approach negates the role of mortality effects later in life.
* Use of Ground-based Worker Limits - Provides a reference point equivalent to the standard that is set on Earth, and recognizes that astronauts face other risks.  However, ground workers remain well below dose limits, and are largely exposed to low-LET radiation where the uncertainties of biological effects are much smaller than for space radiation.
 
[http://www.ncrponline.org/Publications/Press_Releases/153press.html NCRP Report No. 153 (NCRP, 2006)] provides a more recent review of cancer and other radiation risks.  This report also identifies and describes the  information needed to make radiation protection recommendations beyond LEO, contains a comprehensive summary of the current body of evidence for radiation-induced health risks and also makes recommendations on areas requiring future experimentation.<ref name=137-138 />
 
==Current Permissible Exposure Limits==
 
===Career Cancer Risk Limits===
Astronauts' radiation exposure limit is not to exceed 3% of the risk of exposure-induced death (REID) from fatal cancer over their career.  It is NASA's policy to ensure a 95% confidence level (CL) that this limit is not exceeded.  These limits are applicable to all missions in [[Low Earth orbit|low Earth orbit (LEO)]] as well as lunar missions that are less than 180 days in duration.<ref name="127-131">{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=12 June 2012|coauthors=Durante, M.|pages=127–131}}</ref>
 
===Cancer Risk to Dose Relationship===
The relationship between radiation exposure and risk is both age- and gender-specific due to latency effects and differences in tissue types, sensitivities, and life spans between genders.  These relationships are estimated using the methods that are recommended by the NCRP <ref name="NCRP 2000" /> and more recent radiation epidemiology inormation <ref name="Cucinotta and Durante 2006" /><ref name=127-131 /><ref name="Preston 2003">{{cite journal|last=Preston|first=DL|coauthors=Shimizu, Y; Pierce, DA; Suyama, A; Mabuchi, K|title=Studies of mortality of atomic bomb survivors. Report 13: Solid cancer and noncancer disease mortality: 1950-1997|journal=Radiation research|date=Oct 2003|volume=160|issue=4|pages=381–407|pmid=12968934|url=http://cerrie.org/committee_papers/Paper_12-04b.pdf|doi=10.1667/RR3049}}</ref>
 
===The Principle of As Low As Reasonably Achievable===
The as low as reasonably achievable (ALARA) principle is a legal requirement intended to ensure astronaut safety.  An important function of ALARA is to ensure that astronauts do not approach radiation limits and that such limits are not considered as "tolerance values."  ALARA is especially important for space missions in view of the large uncertainties in cancer and other risk projection models.  Mission programs and terrestrial occupational procedures resulting in radiation exposures to astronauts are required to find cost-effective approaches to implement ALARA.<ref name=127-131 />
 
==Evaluating Career Limits==
 
{| class="wikitable" <div style="text-align: center;"> style="float:right;"
!Organ (''T'')
!Tissue weighting factor (''w<sub>T</sub>'')
|-
|Gonads
| align="center" | 0.20
|-
|Bone Marrow (red)
| align="center" | 0.12
|-
|Colon
| align="center" | 0.12
|-
|Lung
| align="center" | 0.12
|-
|Stomach
| align="center" | 0.12
|-
|Bladder
| align="center" | 0.05
|-
|Breast
| align="center" | 0.05
|-
|Liver
| align="center" | 0.05
|-
|Esophagus
| align="center" | 0.05
|-
|Thyroid
| align="center" | 0.05
|-
|Skin
| align="center" | 0.01
|-
|Bone Surface
| align="center" | 0.01
|-
|Remainder*
| align="center" | 0.05
|-
|<sub>*Adrenals, brain, upper intestine,<br> small intestine, kidney, muscle,<br> pancreas, spleen, thymus and uterus.</sub>
|}</div>
 
The risk of cancer is calculated by using [[Dosimetry|radiation dosimetry]] and physics methods.<ref name=127-131 />
 
For the purpose of determining radiation exposure limits at NASA, the probability of fatal cancer is calculated as shown below:
 
# The body is divided into a set of sensitive tissues, and each tissue, ''T'', is assigned a weight, ''w<sub>T</sub>'', according to its estimated contribution to cancer risk.<ref name=127-131 />
# The absorbed dose, ''D<sub>γ</sub>'', that is delivered to each tissue is determined from measured dosimetry.  For the purpose of estimating radiation risk to an organ, the quantity characterizing the ionization density is the LET (keV/μm).<ref name=127-131 />
# For a given interval of LET, between L and ΔL, the dose-equivalent risk (in units of Sievert, where 1 SV = 100 rem) to a tissue, ''T'', ''H<sub>γ</sub>(L)'' is calculated as<br><math>H_\gamma (L) = Q(L)D_\gamma (L)</math><br>where the quality factor, Q(L), is obtained according to the [http://www.icrp.org International Commission on Radiological Protection (ICRP)].<ref name=127-131 />
# The average risk to a tissue, ''T'', due to all types of radiation contributing to the dose is given by <ref name=127-131 /><br><math>H_\gamma = \int D_\gamma (L)Q(L)dL</math><br>or, since <math>D_\gamma (L) =  LF_\gamma (L)</math>, where ''F<sub>γ</sub>(L)'' is the fluence of particles with ''LET=L'', traversing the organ,<br><math>H_\gamma = \int dLQ(L)F_\gamma (L)L</math>
# The effective dose is used as a summation over radiation type and tissue using the tissue weighting factors, ''w<sub>γ</sub>'' <ref name=127-131 /><br><math>E=\sum_\gamma w_\gamma H_\gamma</math>
# For a mission of duration ''t'', the effective dose will be a function of time, ''E(t)'', and the effective dose for mission ''i'' will be  <ref name=127-131 /><br><math>E_i = \int E(t) dt</math>
# The effective dose is used to scale the mortality rate for radiation-induced death from the Japanese survivor data, applying the average of the multiplicative and additive transfer models for solid cancers and the additive transfer model for leukemia by applying life-table methodologies that are based on U.S. population data for background cancer and all causes of death mortality rates. A dose-dose rate effectiveness factor (DDREF) of 2 is assumed.<ref name=127-131 />
 
===Evaluating Cumulative Radiation Risks===
The cumulative cancer fatality risk (%REID) to an astronaut for occupational radiation exposures, ''N'', is found by applying life-table methodologies that can be approximated at small values of %REID by summing over the tissue-weighted effective dose, ''E<sub>i</sub>'', as<br>
::<math>Risk = \sum_{i=1}^N E_i R_0 (age_i, gender)</math>
where ''R<sub>0</sub>'' are the age- and gender- specific radiation mortality rates per unit dose.<ref name=127-131 />
 
For organ dose calculations, NASA uses the model of Billings et al.<ref name=Billings>{{cite book|last=Billings|first=MP|title=Body self-shielding data analysis|year=1973|publisher=McDonnell-Douglas Astronautics Company West|edition=MDC-G4131|coauthors=Yucker, WR; Heckman, BR}}</ref> to represent the self-shielding of the human body in a water-equivalent mass approximation.  Consideration of the orientation of the human body relative to vehicle shielding should be made if it is known, especially for SPEs <ref name=Wilson>{{cite journal|last=Wilson|first=JW|coauthors=Kim, M; Schimmerling, W; Badavi, FF; Thibeaullt, SA; Cucinotta, FA; Shinn, JL; Kiefer, R|title=Issues in space radiation protection|journal=Health Phys,|year=1993|volume=68|pages=50–58|url=http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970006977_1997005102.pdf|doi=10.1097/00004032-199501000-00006}}</ref>
 
Confidence levels for career cancer risks are evaluated using methods that are specified by the [http://www.ncrponline.org/Publications/Press_Releases/126press.html NPRC in Report No. 126].<ref name=127-131 />  These levels were modified to account for the uncertainty in quality factors and space dosimetry.<ref name="Cucinotta and Durante 2006" /><ref name=127-131 /><ref name="Cucinotta 2001">{{cite journal|last=Cucinotta|first=FA|coauthors=Schimmerling, W; Wilson, JW; Peterson, LE; Badhwar, GD; Saganti, PB; Dicello, JF|title=Space radiation cancer risks and uncertainties for Mars missions|journal=Radiation research|date=Nov 2001|volume=156|issue=5 Pt 2|pages=682–8|pmid=11604093|jstor=3580473|doi=10.1667/0033-7587(2001)156[0682:SRCRAU]2.0.CO;2}}</ref>
 
The uncertainties that were considered in evaluating the 95% confidence levels are the uncertainties in:
::* Human epidemiology data, including uncertainties in
::::* statistics limitations of epidemiology data
::::* dosimetry of exposed cohorts
::::* bias, including misclassification of cancer deaths, and
::::*the transfer of risk across populations.
 
::* The DDREF factor that is used to scale acute radiation exposure data to low-dose and dose-rate radiation exposures.
 
::* The radiation quality factor (Q) as a function of LET.
 
::* Space dosimetry
 
The so-called "unknown uncertainties" from the NCRP report No. 126 <ref name="NCRP 1997a">{{cite book|last=NCRP|title=NCRP Report No. 126, Uncertainties in Fatal Cancer Risk Estimates Used in Radiation Protection|year=1997|publisher=NCRP|location=Bethesda, Md|url=http://www.ncrponline.org/Publications/Press_Releases/126press.html}}</ref> are ignored by NASA.
 
==Models of Cancer Risks and Uncertainties==
 
===Life-table methodology===
The double- detriment life-table approach is what is recommended by the [http://www.ncrponline.org/ National Council on Radiation Protection and Measurements (NPRC)] <ref name="NCRP 2000" /> to measure radiation cancer mortality risks.  The age-specific mortality of a population is followed over its entire life span with competing risks from radiation and all other causes of death described.<ref name="Bunger 1981">{{cite journal|last=Bunger|first=BM|coauthors=Cook, JR; Barrick, MK|title=Life table methodology for evaluating radiation risk: an application based on occupational exposures|journal=Health physics|date=Apr 1981|volume=40|issue=4|pages=439–55|pmid=7228696|url=http://journals.lww.com/health-physics/Abstract/1981/04000/Life_Table_Methodology_for_Evaluating_Radiation.2.aspx|doi=10.1097/00004032-198104000-00002}}</ref><ref name="144-145">{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=8 June 2012|coauthors=Durante, M.|pages=144–145}}</ref>
 
For a homogenous population receiving an effective dose E at age a<sub>E</sub>, the probability of dying in the age-interval from ''a'' to ''a+1'' is described by the background mortality-rate for all causes of death, ''M(a)'', and the radiation cancer mortality rate, ''m(E,a<sub>E</sub>,a)'', as:<ref name=144-145 />
 
::<math>q(E,a_E,a)=\frac{M(a)+m(E,a_E,a)}{1+\frac{1}{2}\left[ M(a)+m(E,a_E,a)\right]}</math>
 
The survival probability to age, ''a'', following an exposure, ''E'' at age ''a<sub>E</sub>'', is:<ref name=144-145 />
 
::<math>S(E,a_E,a)= \prod_{u=a_E}^{a-1} \left[ 1-q(E,a_E,u)\right]</math>
 
The excessive lifetime risk (ELR - the increased probability that an exposed individual will die from cancer) is defined by the difference in the conditional survival probabilities for the exposed and the unexposed groups as:<ref name=144-145 />
 
::<math>ELR=\sum_{a=a_E}^ \infty \left[M(a)+m(E,a_E,a)\right]S(E,a_E,a)-\sum_{a=a_E}^ \infty M(a)S(0,a_E,a)</math>
 
A minimum latency-time of 10 years is often used for low-LET radiation.<ref name="NCRP 2000" />  Alternative assumptions should be considered for high-LET radiation.  The REID (the lifetime risk that an individual in the population will die from cancer caused by radiation exposure) is defined by:<ref name=144-145 />
 
::<math>REID=\sum_{a=a_E}^\infty m(E,a_E,a)S(E,a_E,a)</math>
 
Generally, the value of the REID exceeds the value of the ELR by 10-20%.
 
The average loss of life-expectancy, LLE, in the population is defined by:<ref name=144-145 />
 
::<math>LLE=\sum_{a=a_E}^\infty S(0,a_E,a) - \sum_{a=a_E}^\infty S(E,a_E,a)</math>
 
The loss of life-expectancy among exposure-induced-deaths (LLE-REID) is defined by:<ref name=144-145 /><ref name="Vaeth 1990">{{cite journal|last=Vaeth|first=M|coauthors=Pierce, DA|title=Calculating excess lifetime risk in relative risk mdels|journal=Environmental Health Perspectives|year=1990|volume=81|pages=83–94|jstor=3431010|doi=10.1289/ehp.908783}}</ref>
 
::<math>LLE-REID=\frac {LLE}{REID}</math>
 
===Uncertainties in Low-LET Epidemiology Data===
The low-LET mortality rate per Sievert, ''m<sub>i</sub>'' is written<br>
::<math>m(E,a_x,a) = \frac {m_0 (E,a_x,a)}{DDREF} \frac {x_D x_s x_T x_B}{x_{Dr}}</math>
where ''m<sub>0</sub>'' is the baseline mortality rate per Sievert and ''x<sub>α</sub>'' are quantiles (random variables) whose values are sampled from associated probability distribution functions (PDFs), ''P(X<sub>a</sub>)''.<ref name=145-147>{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=8 June 2012|coauthors=Durante, M.|pages=145–147}}</ref>
 
[http://www.ncrponline.org/Publications/Press_Releases/126press.html NPRC in Report No. 126] defines the following subjective PDFs, ''P(X<sub>a</sub>)'', for each factor that contributes to the acute low-LET risk projection:<ref name=145-147 />
# ''P<sub>dosimetry</sub>'' is the random and systematic errors in the estimation of the doses received by atomic-bomb blast survivors.
# ''P<sub>statistical</sub>'' is the distribution in uncertainty in the point estimate of the risk coefficient, ''r<sub>0</sub>''.
# ''P<sub>bias</sub>'' is any bias resulting for over- or under-reporting cancer deaths.
# ''P<sub>transfer</sub>'' is the uncertainty in the transfer of cancer risk following radiation exposure from the Japanese population to the U.S. population.
# ''P<sub>Dr</sub>'' is the uncertainty in the knowledge of the extrapolation of risks to low dose and dose-rates, which are embodied in the DDREF.
 
==Risk in Context of Exploration Mission Operational Scenarios==
The accuracy of galactic cosmic ray environmental models, transport codes and nuclear interaction cross sections allow NASA to predict space environments and organ exposure that may be encountered on long-duration space missions.  The lack of knowledge of the biological effects of radiation exposure raise major questions about risk prediction.<ref name="155-161">{{cite web|last=Cucinotta|first=F.A.|title=Risk of Radiation Carcinogenesis|url=http://humanresearchroadmap.nasa.gov/evidence/reports/Carcinogenesis.pdf|work=Human Health and Performance Risks of Space Exploration Missions Evidence reviewed by the NASA Human Research Program|publisher=NASA|accessdate=6 June 2012|coauthors=Durante, M.|pages=155–161}}</ref>
 
The cancer risk projection for space missions is found by <ref name=155-161 /><br>
::<math>m_J(E,a_E,a)_{lJ}(E,a_E,a) \int dL \frac{dF}{dL}LQ_{trial-J}(L)X_{L-J}</math>
where <math>\frac{dF}{dL}</math> represents the folding of predictions of tissue-weighted LET spectra behind spacecraft shielding with the radiation mortality rate to form a rate for trial ''J''.
 
Alternatively, particle-specific energy spectra, ''F<sub>j</sub>(E)'', for each ion, ''j'', can be used <ref name=155-161 /><br>
::<math>m_J (E,a_E,a) = m_{lJ}(E,a_E,a) \sum_j (E)L(E)Q_{trial-J}(L(E))x_{L-J}</math>.
 
The result of either of these equations is inserted into the expression for the REID.<ref name=155-161 />
 
Related probability distribution functions (PDFs) are grouped together into a combined probability distribution function, ''P<sub>cmb</sub>(x)''.  These PDFs are related to the risk coefficient of the normal form (dosimetry, bias and statistical uncertainties).  After a sufficient number of trials have been completed (approximately 10<sup>5</sup>), the results for the REID estimated are binned and the median values and confidence intervals are found.<ref name=155-161 />
 
The chi-squared (χ<sup>2</sup>) test is used for determining whether two separate PDFs are significantly different (denoted ''p<sub>1</sub>(R<sub>i</sub>)'' and ''p<sub>2</sub>(R<sub>i</sub>)'', respectively).  Each ''p(R<sub>i</sub>) follows a Poisson distribution with variance <math>\sqrt{p(R_i)}</math>.<ref name=155-161 />
 
The χ<sup>2</sup> test for n-degrees of freedom characterizing the dispersion between the two distributions is <ref name=155-161 /><br>
::<math>\chi^2=\sum_n \frac{\left[p_1(R_n)-p_2(R_n)\right]^2}{\sqrt{p_1^2(R_n)+p_2^2(R_n)}}</math>.
 
The probability, ''P(ņχ<sup>2</sup>)'', that the two distributions are the same is calculated once χ<sup>2</sup> is determined.<ref name=155-161 />
 
===Radiation Carcinogenesis Mortality Rates===
Age- and gender-dependent mortality rare per unit dose, multiplied by the radiation quality factor and reduced by the DDREF is used for projecting lifetime cancer fatality risks.  Acute gamma ray exposures are estimated.<ref name="NCRP 2000" />  The additivity of effects of each component in a radiation field is also assumed.
 
Rates are approximated using data gathered from Japanese atomic bomb survivors.  There are two different models that are considered when transferring risk from Japanese to U.S. populations.
 
* Multiplicative transfer model - assumes that radiation risks are proportional to spontaneous or background cancer risks.
* Additive transfer model - assumes that radiation risk acts independently of other cancer risks.
 
The NCRP recommends a mixture model to be used that contains fractional contributions from both methods.<ref name="NCRP 2000" />
 
The radiation mortality rate is defined as:
 
::<math> m(E,a_E,a)=\left[ERR(a_E, a)M_c(a)+(1-v)EAR(a_E,a)\right]{\frac{\sum_LQ(L)F(L)L}{DDREF}}</math>
 
Where:<br>
::ERR = excess relative risk per Sievert
::EAR = excess additive risk per Sievert
::M<sub>c</sub>(a) = the gender- and age-specific cancer mortality rate in the U.S. population
::F = the tissue-weighted fluence
::L = the LET
::v = the fractional division between the assumption of the multiplicative and additive risk transfer models.  For solid cancer, it is assumed that v=1/2 and for leukemia, it is assumed that v=0.
 
==Biological and Physical Countermeasures==
Identifying effective countermeasures that reduce the risk of biological damage is still a long term goal for space researchers.  These countermeasures are probably not needed for extended duration lunar missions,<ref name="Durante 2008" /> but will be needed for other long-duration missions to Mars and beyond.<ref name=155-161 /> On 31 May 2013, NASA scientists reported that a possible [[manned mission to Mars]] may involve a great [[radiation|radiation risk]] based on the amount of [[radiation|energetic particle radiation]] detected by the [[Radiation assessment detector|RAD]] on the [[Mars Science Laboratory]] while traveling from the [[Earth]] to [[Mars]] in 2011-2012.<ref name="SCI-20130531a" /><ref name="SCI-20130531b" /><ref name="NYT-20130530" /><ref name="SN-20130629" />
 
There are three fundamental ways to reduce exposure to ionizing radiation:<ref name=155-161 />
* increasing the distance from the radiation source
* reducing the exposure time
* shielding (i.e.: a physical barrier)
 
Since space radiation is omnidirectional, distance has no bearing in space.  Also, since the duration of space missions will only increase, reducing the exposure time is not a feasible option.
 
Shielding is a plausible option, but due to current launch mass restrictions, it is prohibitively costly.  Also, the current uncertainties in risk projection prevent the actual benefit of shielding from being determined.  Strategies such as drugs and dietary supplements to reduce the effects of radiation, as well as the selection of crew members are being evaluated as viable options for reducing exposure to radiation and effects of irradiation.  Shielding is an effective protective measure for terrestrial radiation workers.  In space, high-energy radiation is very penetrating and the effectiveness of radiation shielding depends on the atomic make-up of the material used.<ref name=155-161 />
 
Antioxidants are effectively used to prevent the damage caused by radiation injury and oxygen poisoning (the formation of reactive oxygen species), but since antioxidants work by rescuing cells from a particular form of cell death (apoptosis), they may not protect against damaged cells that can initiate tumor growth.<ref name=155-161 />
 
==Benefits to Earth==
{{Empty section|date=June 2012}}
 
==Evidence Sub-pages==
The evidence and updates to projection models for cancer risk from low-LET radiation are reviewed periodically by several prestigious bodies, which include the following organizations:<ref name=127-131 />
* The NAS Committee on the Biological Effects of Ionizing Radiation
* The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)
* The ICRP
* The NCRP
 
These committees release new reports about every 10 years on cancer risks that are applicable to low-LET radiation exposures.  Overall, the estimates of cancer risks among the different reports of these panels will agree within a factor of two or less.  There is continued controversy for doses that are below 5 mSv, however, and for low dose-rate radiation because of debate over the linear no-threshold hypothesis that is often used in statistical analysis of these data.  The BEIR VII report,<ref name="BIER 2006" /> which is the most recent of the major reports is used in the following sub-pages.  Evidence for low-LET cancer effects must be augmented by information on protons, neutrons, and HZE nuclei that is only available in experimental models.  Such data have been reviewed by NASA several times in the past and by the NCRP.<ref name="NCRP 2000" /><ref name=127-131 /><ref name="NCRP 1989">{{cite book|last=NCRP|first=NCRP Report No. 98|title=Guidance on radiation received in space activities|year=1989|publisher=NCRP|location=Bethesda, Md.|url=http://www.ncrppublications.org/Reports/098}}</ref><ref name="NCRP 2006">{{cite book|last=NCRP|first=NCRP Report No. 153|title=Information needed to make radiation protection recommendations for space missions beyond low-Earth orbit|year=2006|publisher=NCRP|location=Bethesda, Md.|url=http://www.ncrponline.org/Publications/Press_Releases/153press.html}}</ref>
 
[[Epidemiology data for low-linear energy transfer radiation|Epidemiology data for low linear energy transfer radiation]]
 
[[Radiobiology evidence for protons and HZE nuclei]]
 
[[Radiation carcinogenesis in past space missions]]
 
==See also==
*[[Dosimetry]]
*[[Health threat from cosmic rays]]
*[[Radiation syndromes#Spaceflight|Radiation Syndrome]]
*[[Central nervous system effects from radiation exposure during spaceflight]]
 
==External links==
*{{cite journal |last1=Asaithamby |first1=A |last2=Uematsu |first2=N |last3=Chatterjee |first3=A |last4=Story |first4=MD |last5=Burma |first5=S |last6=Chen |first6=DJ |title=Repair of HZE-particle-induced DNA double-strand breaks in normal human fibroblasts |journal=Radiation Research |date=April 2008 |volume=169 |issue=4 |pages=437–46 |pmid=18363429 |doi=10.1667/RR1165.1}}
*{{cite journal |last1=Chatterjee |first1=A. |last2=Borak |first2=T.H. |title=Physical and biological studies with protons and HZE particles in a NASA supported research center in radiation health |journal=Physica Medica |year=2001 |volume=17 |issue=1 |pages=59–66 |url=http://www.physicamedica.com/VOLXVII_S1/13-CHATTERJEE-BORAK.pdf |accessdate=5 June 2012}}
*{{cite web |last=Snyder |first=Kendra |title=One-Two Particle Punch Poses Greater Risk for Astronauts |url=http://www.bnl.gov/bnlweb/pubaf/pr/pr_display.asp?prid=06-99 |publisher=Brookhaven National Laboratory |accessdate=6 June 2012 |date=August 2006}}
*{{cite journal |last1=Bucker |first1=H |last2=Facius |first2=R |title=The role of HZE particles in space flight: results from spaceflight and ground-based experiments |journal=Acta Astronautica |date=Sep–Oct 1981 |volume=8 |issue=9–10 |pages=1099–107 |pmid=11543100 |doi=10.1016/0094-5765(81)90084-9}}
*{{cite book |author=Committee on the Evaluation of Radiation Shielding for Space Exploration, Aeronautics and Space Engineering Board, Division on Engineering and Physical Sciences, National Research Council of the National Academies |title=Managing space radiation risk in the new era of space exploration |year=2008 |publisher=National Academies Press |location=Washington, D.C. |isbn=978-0-309-11383-0}}
* [http://three.usra.edu/ The Health Risks of Extraterrestrial Environments]
 
==References==
{{reflist|2}}
 
{{NASA|article=Human Health and Performance Risks of Space Exploration Missions|url=http://humanresearchroadmap.nasa.gov/evidence/reports/EvidenceBook.pdf|comment=NASA SP-2009-3405}}
 
{{Space medicine}}
 
[[Category:Space medicine]]

Revision as of 05:18, 17 August 2013

Template:Multiple issues

File:Iss002e5952.jpg
The Phantom Torso, seen here in the Destiny laboratory on the International Space Station (ISS), is designed to measure the effects of radiation on organs inside the body by using a torso that is similar to those used to train radiologists on Earth. The torso is equivalent in height and weight to an average adult male. It contains radiation detectors that will measure, in real-time, how much radiation the brain, thyroid, stomach, colon, and heart and lung area receive on a daily basis. The data will be used to determine how the body reacts to and shields its internal organs from radiation, which will be important for longer duration space flights.

Astronauts are exposed to approximately 50-2,000 mSv (mili-Sievert) while on six-month-duration missions to the International Space Station (ISS), the moon and beyond.[1][2] The risk of cancer caused by ionizing radiation is well documented at radiation doses beginning at 50 mSv and above.[1][3][4]

Related radiological effect studies have shown that survivors of the atomic bomb explosions in Hiroshima and Nagasaki, nuclear reactor workers and patients who have undergone therapeutic radiation treatments have received low-linear energy transfer (LET) radiation (x-rays and gamma rays) doses in the same 50-2000 mSv range.[5]

Composition of space radiation

While in space, astronauts are exposed to protons, helium nuclei, and high-Z high energy ions (HZE ions), as well as secondary radiation from nuclear reactions from spacecraft parts or tissue.[6]

Space radiation is composed mostly of high-energy protons, helium nuclei, and HZE ions. The ionization patterns in molecules, cells, tissues and the resulting biological insults are distinct from typical terrestrial radiation (x-rays and gamma rays, which are low-LET radiation). GCRs (galactic cosmic rays) from outside of the Milky Way galaxy consist mostly of highly energetic protons with a small component of HZE ions.[6]

Prominent HZE ions:

GCR (galactic cosmic ray)[7] energy spectra peaks (with median energy peaks up to 1,000 MeV/amu) and nuclei (energies up to 10,000 MeV/amu) are important contributors to the dose equivalent.[6]

Uncertainties in cancer projections

One of the main roadblocks to interplanetary travel is the risk of cancer caused by radiation exposure. The largest contributors to this roadblock are: (1) The large uncertainties associated with cancer risk estimates, (2) The unavailability of simple and effective countermeasures and (3) The inability to determine the effectiveness of countermeasures.
[6] Operational parameters that need to be optimized to help mitigate these risks include:[6]

  • length of space missions
  • crew age
  • crew gender
  • shielding
  • biological countermeasures

Major uncertainties[6]

  • effects on biological damage related to differences between space radiation and x-rays
  • dependence of risk on dose-rates in space related to the biology of DNA repair, cell regulation and tissue responses
  • predicting solar particle events (SPEs)
  • extrapolation from experimental data to humans and between human populations
  • individual radiation sensitivity factors (genetic, epigenetic, dietary or "healthy worker" effects)

Minor uncertainties[6]

  • data on GCR (galactic cosmic ray) environments
  • physics of shielding assessments related to transmission properties of radiation through materials and tissue
  • microgravity effects on biological responses to radiation
  • errors in human data (statistical, dosimetry or recording inaccuracies)

Quantitative methods have been developed to propagate uncertainties that contribute to cancer risk estimates. The contribution of microgravity effects on space radiation has not yet been estimated, but it is expected to be small. The effects of changes in oxygen levels or in immune dysfunction on cancer risks are largely unknown and are of great concern during space flight.[6]

Types of cancer caused by radiation exposure

Studies are being conducted on populations accidentally exposed to radiation (Chernobyl, production sites as well as Hiroshima and Nagasaki). These studies show strong evidence for cancer morbidity as well as mortality risks at more than 12 tissue sites. The largest risks for adults who have been studied include several types of leukemia, including myeloid leukemia [8] and acute lymphatic lymphoma [8] as well as tumors of the lung, breast, stomach, colon, bladder and liver. Inter-gender variations are very likely due to the differences in the natural incidence of cancer in males and females. Another variable is the additional risk for cancer of the breast, ovaries and lungs in females.[9] There is also evidence of a declining risk of cancer caused by radiation with increasing age, but the magnitude of this reduction above the age of 30 is uncertain.[6]

It is unknown whether high-LET radiation could cause the same types of tumors as low-LET radiation, but differences should be expected.[8]

The ratio of a dose of high-LET radiation to a dose of x-rays or gamma rays that produce the same biological effect are called relative biological effectiveness (BRE) factors. The types of tumors in humans who are exposed to space radiation will be different from those who are exposed to low-LET radiation. This is evidenced by a study that observed mice with neutrons and have RBEs that vary with the tissue type and strain.[8]

Approaches for Setting Acceptable Risk Levels

The various approaches to setting acceptable levels of radiation risk are summarized below:[10]

Comparison of Radiation Doses - includes the amount detected on the trip from Earth to Mars by the RAD on the MSL (2011 - 2013).[11][12][13][14]
  • Unlimited Radiation Risk - NASA management, the families of loved ones of astronauts, and taxpayers would find this approach unacceptable.
  • Comparison to Occupational Fatalities in Less-safe Industries - The life-loss from attributable radiation cancer death is less than that from most other occupational deaths. At this time, this comparison would also be very restrictive on ISS operations because of continued improvements in ground-based occupational safety over the last 20 years.
  • Comparison to Cancer Rates in General Population - The number of years of life-loss from radiation-induced cancer deaths can be significantly larger than from cancer deaths in the general population, which often occur late in life (> age 70 years) and with significantly less numbers of years of life-loss.
  • Doubling Dose for 20 Years Following Exposure - Provides a roughly equivalent comparison based on life-loss from other occupational risks or background cancer fatalities during a worker's career, however, this approach negates the role of mortality effects later in life.
  • Use of Ground-based Worker Limits - Provides a reference point equivalent to the standard that is set on Earth, and recognizes that astronauts face other risks. However, ground workers remain well below dose limits, and are largely exposed to low-LET radiation where the uncertainties of biological effects are much smaller than for space radiation.

NCRP Report No. 153 (NCRP, 2006) provides a more recent review of cancer and other radiation risks. This report also identifies and describes the information needed to make radiation protection recommendations beyond LEO, contains a comprehensive summary of the current body of evidence for radiation-induced health risks and also makes recommendations on areas requiring future experimentation.[10]

Current Permissible Exposure Limits

Career Cancer Risk Limits

Astronauts' radiation exposure limit is not to exceed 3% of the risk of exposure-induced death (REID) from fatal cancer over their career. It is NASA's policy to ensure a 95% confidence level (CL) that this limit is not exceeded. These limits are applicable to all missions in low Earth orbit (LEO) as well as lunar missions that are less than 180 days in duration.[15]

Cancer Risk to Dose Relationship

The relationship between radiation exposure and risk is both age- and gender-specific due to latency effects and differences in tissue types, sensitivities, and life spans between genders. These relationships are estimated using the methods that are recommended by the NCRP [9] and more recent radiation epidemiology inormation [1][15][16]

The Principle of As Low As Reasonably Achievable

The as low as reasonably achievable (ALARA) principle is a legal requirement intended to ensure astronaut safety. An important function of ALARA is to ensure that astronauts do not approach radiation limits and that such limits are not considered as "tolerance values." ALARA is especially important for space missions in view of the large uncertainties in cancer and other risk projection models. Mission programs and terrestrial occupational procedures resulting in radiation exposures to astronauts are required to find cost-effective approaches to implement ALARA.[15]

Evaluating Career Limits

Organ (T) Tissue weighting factor (wT)
Gonads 0.20
Bone Marrow (red) 0.12
Colon 0.12
Lung 0.12
Stomach 0.12
Bladder 0.05
Breast 0.05
Liver 0.05
Esophagus 0.05
Thyroid 0.05
Skin 0.01
Bone Surface 0.01
Remainder* 0.05
*Adrenals, brain, upper intestine,
small intestine, kidney, muscle,
pancreas, spleen, thymus and uterus.

The risk of cancer is calculated by using radiation dosimetry and physics methods.[15]

For the purpose of determining radiation exposure limits at NASA, the probability of fatal cancer is calculated as shown below:

  1. The body is divided into a set of sensitive tissues, and each tissue, T, is assigned a weight, wT, according to its estimated contribution to cancer risk.[15]
  2. The absorbed dose, Dγ, that is delivered to each tissue is determined from measured dosimetry. For the purpose of estimating radiation risk to an organ, the quantity characterizing the ionization density is the LET (keV/μm).[15]
  3. For a given interval of LET, between L and ΔL, the dose-equivalent risk (in units of Sievert, where 1 SV = 100 rem) to a tissue, T, Hγ(L) is calculated as

    where the quality factor, Q(L), is obtained according to the International Commission on Radiological Protection (ICRP).[15]
  4. The average risk to a tissue, T, due to all types of radiation contributing to the dose is given by [15]

    or, since , where Fγ(L) is the fluence of particles with LET=L, traversing the organ,
  5. The effective dose is used as a summation over radiation type and tissue using the tissue weighting factors, wγ [15]
  6. For a mission of duration t, the effective dose will be a function of time, E(t), and the effective dose for mission i will be [15]
  7. The effective dose is used to scale the mortality rate for radiation-induced death from the Japanese survivor data, applying the average of the multiplicative and additive transfer models for solid cancers and the additive transfer model for leukemia by applying life-table methodologies that are based on U.S. population data for background cancer and all causes of death mortality rates. A dose-dose rate effectiveness factor (DDREF) of 2 is assumed.[15]

Evaluating Cumulative Radiation Risks

The cumulative cancer fatality risk (%REID) to an astronaut for occupational radiation exposures, N, is found by applying life-table methodologies that can be approximated at small values of %REID by summing over the tissue-weighted effective dose, Ei, as

where R0 are the age- and gender- specific radiation mortality rates per unit dose.[15]

For organ dose calculations, NASA uses the model of Billings et al.[17] to represent the self-shielding of the human body in a water-equivalent mass approximation. Consideration of the orientation of the human body relative to vehicle shielding should be made if it is known, especially for SPEs [18]

Confidence levels for career cancer risks are evaluated using methods that are specified by the NPRC in Report No. 126.[15] These levels were modified to account for the uncertainty in quality factors and space dosimetry.[1][15][19]

The uncertainties that were considered in evaluating the 95% confidence levels are the uncertainties in:

  • Human epidemiology data, including uncertainties in
  • statistics limitations of epidemiology data
  • dosimetry of exposed cohorts
  • bias, including misclassification of cancer deaths, and
  • the transfer of risk across populations.
  • The DDREF factor that is used to scale acute radiation exposure data to low-dose and dose-rate radiation exposures.
  • The radiation quality factor (Q) as a function of LET.
  • Space dosimetry

The so-called "unknown uncertainties" from the NCRP report No. 126 [20] are ignored by NASA.

Models of Cancer Risks and Uncertainties

Life-table methodology

The double- detriment life-table approach is what is recommended by the National Council on Radiation Protection and Measurements (NPRC) [9] to measure radiation cancer mortality risks. The age-specific mortality of a population is followed over its entire life span with competing risks from radiation and all other causes of death described.[21][22]

For a homogenous population receiving an effective dose E at age aE, the probability of dying in the age-interval from a to a+1 is described by the background mortality-rate for all causes of death, M(a), and the radiation cancer mortality rate, m(E,aE,a), as:[22]

The survival probability to age, a, following an exposure, E at age aE, is:[22]

The excessive lifetime risk (ELR - the increased probability that an exposed individual will die from cancer) is defined by the difference in the conditional survival probabilities for the exposed and the unexposed groups as:[22]

A minimum latency-time of 10 years is often used for low-LET radiation.[9] Alternative assumptions should be considered for high-LET radiation. The REID (the lifetime risk that an individual in the population will die from cancer caused by radiation exposure) is defined by:[22]

Generally, the value of the REID exceeds the value of the ELR by 10-20%.

The average loss of life-expectancy, LLE, in the population is defined by:[22]

The loss of life-expectancy among exposure-induced-deaths (LLE-REID) is defined by:[22][23]

Uncertainties in Low-LET Epidemiology Data

The low-LET mortality rate per Sievert, mi is written

where m0 is the baseline mortality rate per Sievert and xα are quantiles (random variables) whose values are sampled from associated probability distribution functions (PDFs), P(Xa).[24]

NPRC in Report No. 126 defines the following subjective PDFs, P(Xa), for each factor that contributes to the acute low-LET risk projection:[24]

  1. Pdosimetry is the random and systematic errors in the estimation of the doses received by atomic-bomb blast survivors.
  2. Pstatistical is the distribution in uncertainty in the point estimate of the risk coefficient, r0.
  3. Pbias is any bias resulting for over- or under-reporting cancer deaths.
  4. Ptransfer is the uncertainty in the transfer of cancer risk following radiation exposure from the Japanese population to the U.S. population.
  5. PDr is the uncertainty in the knowledge of the extrapolation of risks to low dose and dose-rates, which are embodied in the DDREF.

Risk in Context of Exploration Mission Operational Scenarios

The accuracy of galactic cosmic ray environmental models, transport codes and nuclear interaction cross sections allow NASA to predict space environments and organ exposure that may be encountered on long-duration space missions. The lack of knowledge of the biological effects of radiation exposure raise major questions about risk prediction.[25]

The cancer risk projection for space missions is found by [25]

where represents the folding of predictions of tissue-weighted LET spectra behind spacecraft shielding with the radiation mortality rate to form a rate for trial J.

Alternatively, particle-specific energy spectra, Fj(E), for each ion, j, can be used [25]

.

The result of either of these equations is inserted into the expression for the REID.[25]

Related probability distribution functions (PDFs) are grouped together into a combined probability distribution function, Pcmb(x). These PDFs are related to the risk coefficient of the normal form (dosimetry, bias and statistical uncertainties). After a sufficient number of trials have been completed (approximately 105), the results for the REID estimated are binned and the median values and confidence intervals are found.[25]

The chi-squared (χ2) test is used for determining whether two separate PDFs are significantly different (denoted p1(Ri) and p2(Ri), respectively). Each p(Ri) follows a Poisson distribution with variance .[25]

The χ2 test for n-degrees of freedom characterizing the dispersion between the two distributions is [25]

.

The probability, P(ņχ2), that the two distributions are the same is calculated once χ2 is determined.[25]

Radiation Carcinogenesis Mortality Rates

Age- and gender-dependent mortality rare per unit dose, multiplied by the radiation quality factor and reduced by the DDREF is used for projecting lifetime cancer fatality risks. Acute gamma ray exposures are estimated.[9] The additivity of effects of each component in a radiation field is also assumed.

Rates are approximated using data gathered from Japanese atomic bomb survivors. There are two different models that are considered when transferring risk from Japanese to U.S. populations.

  • Multiplicative transfer model - assumes that radiation risks are proportional to spontaneous or background cancer risks.
  • Additive transfer model - assumes that radiation risk acts independently of other cancer risks.

The NCRP recommends a mixture model to be used that contains fractional contributions from both methods.[9]

The radiation mortality rate is defined as:

Where:

ERR = excess relative risk per Sievert
EAR = excess additive risk per Sievert
Mc(a) = the gender- and age-specific cancer mortality rate in the U.S. population
F = the tissue-weighted fluence
L = the LET
v = the fractional division between the assumption of the multiplicative and additive risk transfer models. For solid cancer, it is assumed that v=1/2 and for leukemia, it is assumed that v=0.

Biological and Physical Countermeasures

Identifying effective countermeasures that reduce the risk of biological damage is still a long term goal for space researchers. These countermeasures are probably not needed for extended duration lunar missions,[3] but will be needed for other long-duration missions to Mars and beyond.[25] On 31 May 2013, NASA scientists reported that a possible manned mission to Mars may involve a great radiation risk based on the amount of energetic particle radiation detected by the RAD on the Mars Science Laboratory while traveling from the Earth to Mars in 2011-2012.[11][12][13][14]

There are three fundamental ways to reduce exposure to ionizing radiation:[25]

  • increasing the distance from the radiation source
  • reducing the exposure time
  • shielding (i.e.: a physical barrier)

Since space radiation is omnidirectional, distance has no bearing in space. Also, since the duration of space missions will only increase, reducing the exposure time is not a feasible option.

Shielding is a plausible option, but due to current launch mass restrictions, it is prohibitively costly. Also, the current uncertainties in risk projection prevent the actual benefit of shielding from being determined. Strategies such as drugs and dietary supplements to reduce the effects of radiation, as well as the selection of crew members are being evaluated as viable options for reducing exposure to radiation and effects of irradiation. Shielding is an effective protective measure for terrestrial radiation workers. In space, high-energy radiation is very penetrating and the effectiveness of radiation shielding depends on the atomic make-up of the material used.[25]

Antioxidants are effectively used to prevent the damage caused by radiation injury and oxygen poisoning (the formation of reactive oxygen species), but since antioxidants work by rescuing cells from a particular form of cell death (apoptosis), they may not protect against damaged cells that can initiate tumor growth.[25]

Benefits to Earth

Template:Empty section

Evidence Sub-pages

The evidence and updates to projection models for cancer risk from low-LET radiation are reviewed periodically by several prestigious bodies, which include the following organizations:[15]

  • The NAS Committee on the Biological Effects of Ionizing Radiation
  • The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)
  • The ICRP
  • The NCRP

These committees release new reports about every 10 years on cancer risks that are applicable to low-LET radiation exposures. Overall, the estimates of cancer risks among the different reports of these panels will agree within a factor of two or less. There is continued controversy for doses that are below 5 mSv, however, and for low dose-rate radiation because of debate over the linear no-threshold hypothesis that is often used in statistical analysis of these data. The BEIR VII report,[4] which is the most recent of the major reports is used in the following sub-pages. Evidence for low-LET cancer effects must be augmented by information on protons, neutrons, and HZE nuclei that is only available in experimental models. Such data have been reviewed by NASA several times in the past and by the NCRP.[9][15][26][27]

Epidemiology data for low linear energy transfer radiation

Radiobiology evidence for protons and HZE nuclei

Radiation carcinogenesis in past space missions

See also

External links

  • One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  • One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  • Template:Cite web
  • One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  • 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  • The Health Risks of Extraterrestrial Environments

References

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

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  1. 1.0 1.1 1.2 1.3 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  2. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  3. 3.0 3.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  4. 4.0 4.1 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  5. Template:Cite web
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Template:Cite web
  7. Template:Cite web
  8. 8.0 8.1 8.2 8.3 Template:Cite web
  9. 9.0 9.1 9.2 9.3 9.4 9.5 9.6 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  10. 10.0 10.1 Template:Cite web
  11. 11.0 11.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  12. 12.0 12.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  13. 13.0 13.1 Template:Cite news
  14. 14.0 14.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  15. 15.00 15.01 15.02 15.03 15.04 15.05 15.06 15.07 15.08 15.09 15.10 15.11 15.12 15.13 15.14 15.15 Template:Cite web
  16. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  17. 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  18. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  19. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  20. 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  21. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  22. 22.0 22.1 22.2 22.3 22.4 22.5 22.6 Template:Cite web
  23. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
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  26. 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

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  27. 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534