Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Space radiation may cause prolonged cellular damage to astronauts

16.04.2008
With major implications for long-duration space travel, a study from the Lombardi Comprehensive Cancer Center at Georgetown University Medical Center demonstrates that the high-energy radiation found in space may lead to premature aging and prolonged oxidative stress in cells.

The findings suggest that astronauts may be at increased risk of colon cancer due to exposure to the high linear energy transfer (LET) radiation found in space.

“Radiation exposure, either intentional or accidental, is inevitable during our lifetimes,” says Kamal Datta, M.D., assistant professor at Lombardi and the study’s lead author. “But with plans for a mission to Mars, we need to understand more about the nature of radiation in space. There is currently no conclusive information for estimating the risk that astronauts may experience.”

The kickoff of Project Constellation – the National Aeronautics and Space Administration (NASA) program to return humans to the moon and travel to Mars – has led to increased scrutiny of radiation exposures during space travel. A 2004 report from the National Academies suggested that cancer incidence may be higher in the astronaut population as compared to the general U.S. population, and the National Research Council published a report last month that recommended increased research into the radiation exposures experienced by astronauts during space travel, as well as development of new radiation shielding technologies.

Current risk estimates for radiation exposure rely exclusively on the cumulative dose a person receives in his or her lifetime. The Lombardi study suggests that a more accurate risk assessment should include not only dose, but also the quality of radiation.

To conduct the study, Datta and his team measured the level of free radicals present as well as the expression of stress response genes in the cells of mice exposed to high-LET radiation similar to that found in space. The researchers concluded that the cellular environment of the gastrointestinal tract was highly oxidative – or full of free radicals – for prolonged periods of time, a state which is conducive to cancer development.

The free radicals produced by the radiation causes damage to cells’ DNA, and as this damage accumulates, it can lead to mutations -- and in some cases, malignant tumors. The prolonged exposure to free radicals creates ample opportunity for DNA damage to accumulate within individual cells. In fact, Datta and his team observed that the stress response continued for as long as two months after exposure to the high-LET radiation.

In addition the cellular damage from oxidative stress, the researchers also found that the mice exposed to the high-LET radiation aged prematurely. Datta says the mice’s coats became prematurely grey, an observation the team plans to follow-up with MRI brain scans.

The Lombardi study, funded by NASA and presented at the 2008 American Association for Cancer Research annual meeting, compared these effects to those from low-LET radiation, such as gamma rays. Low-LET radiation is often used in medical imaging and radiotherapies for cancer, so humans are more often exposed to this class of radiation. The study showed that low-LET radiation did not create an oxidative environment in cells, though both types of radiation did induce a pro-inflammatory response.

High-LET radiation is found in solar flares and is made up of high-energy protons, charged iron particles, and some gamma radiation. The earth’s atmosphere blocks the majority of this radiation, preventing exposure to these particles in normal life. High-LET radiation is known to cause a great deal of damage in a localized area, whereas the impact of low-LET tends to be more diffuse within a tissue.

Karen Mallet | EurekAlert!
Further information:
http://www.georgetown.edu
http://lombardi.georgetown.edu

More articles from Physics and Astronomy:

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

Construction of practical quantum computers radically simplified

05.12.2016 | Information Technology

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>