NASA CATARACT STUDY MAY HELP ASTRONAUTS SEE CLEARLY

[Susan Gawarecki <loc@ICX.NET>]

Radsafers might be interested in the following news release from NASA.



--Susan Gawarecki



***



Dwayne Brown

Headquarters, Washington          Dec. 17, 2001

(Phone: 202/358-1726)



RELEASE: 01-245



NASA CATARACT STUDY MAY HELP ASTRONAUTS SEE CLEARLY



     A recent NASA study that showed astronauts who have 

spent more time in space are more likely to have cataracts 

will pave the way for developing new techniques to protect 

space travelers. 



A research team led by Dr. Francis A. Cucinotta of the 

Radiation Health Office at NASA's Johnson Space Center in 

Houston studied 48 cataract cases in current and retired 

astronauts. The team discovered a significant increase in 

cataracts for those who had higher "lens doses" from space 

radiation. They also found those exposed to higher amounts of 

space radiation got cataracts at a younger age than 

astronauts who received lower dosages. 



The team linked the increased incidence of cataracts to the 

presence of heavy-ion radiation in space -- outside Earth's 

protective atmosphere. The study suggests that long-duration 

space station crewmembers are at higher risk for cataracts 

than space shuttle astronauts. In the past, space shuttle 

crewmembers spent less time in space and often in lower 

inclinations where Earth's magnetic field offers some 

protection from radiation.



NASA is  developing countermeasures to further protect space 

travelers. These include reducing exposure to ultraviolet 

(UV) radiation from sunlight, use of selective UV-blocking 

eyewear, adding shielding on the International Space Station, 

and conducting research to investigate the effectiveness of 

anti-oxidants like vitamins C and E and beta-carotene in 

slowing the progression of age-related and radiation-induced 

cataracts. 



Research studies on cataracts and the effectiveness of anti-

oxidants will be performed by NASA-funded investigators at 

Brookhaven National Laboratory in Upton, N.Y., where particle 

accelerators can reproduce the high-energy heavy ions that 

occur in space.



NASA already is improving the space station's existing 

radiation shielding, especially in the living areas like the 

sleeping quarters and the galley where astronauts spend most 

of their time. Materials with high hydrogen-content like 

polyethylene have been shown to reduce radiation. NASA also 

actively monitors space radiation levels so astronauts can 

move to the best-shielded locations if radiation levels 

increase because of solar disturbances. 



In addition, NASA follows standard radiation-protection 

practices recommended by the U.S. National Academy of 

Sciences Space Science Board and the U.S. National Council on 

Radiation Protection and Measurements to determine acceptable 

levels of risk for astronauts.



To help protect astronauts' health, NASA is improving the 

astronaut optometric exam to include digital imaging and 

analysis of the crystalline lens of the eye. This will allow 

NASA to better understand the different types of cataracts 

occurring in astronauts and their progression from mild to 

more severe. 



This current study was not able to determine whether 

astronauts as a group are more susceptible to cataracts than 

other people, since good vision and health are two criteria 

for astronaut selection. However, NASA is reviewing a 

proposal to perform a follow-on study that would compare 

astronauts to a group of people with similar characteristics 

who have not participated in space missions. Results from 

this study should be available in three to five years.



The results of the study, Space Radiation and Cataracts in 

Astronauts, by F. A. Cucinotta, F. K. Manuel, J. Jones, G. 

Iszard, J. Murray, B. Djojonegoro and M. Wear, have been 

published in the November 2001 issue of the journal Radiation 

Research. An abstract of the study is available on the 

Internet at: 



http://spaceresearch.nasa.gov/general_info/pressrel.html



                               -end-

-- 

.....................................................

Susan L. Gawarecki, Ph.D., Executive Director

Oak Ridge Reservation Local Oversight Committee

Please visit our Web site - http://www.local-oversight.org

.....................................................

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