Astronauts’ Children Unlikely to Inherit Cosmic Ray-Induced Genetic Defects

April 14, 2005

Male astronauts exposed to cosmic rays in space are not likely to pass on possible mutations caused by the rays to their offspring, according to a new study by a collaboration that includes a scientist from the U.S. Department of Energy’s Brookhaven National Laboratory. The results are published in the April 11, 2005, online issue of the Proceedings of the National Academy of Sciences.

“We concluded that one hazard to male astronauts as a result of exposure to cosmic rays - high-energy, heavy nuclei that zoom in from deep space - is probably temporary sterility, but not significant effects to their future offspring,” said biophysicist Richard Setlow, the Brookhaven scientist who participated in the research.

Cosmic-ray exposure could pose serious health risks to astronauts, who are not protected by Earth’s atmosphere and magnetic field - natural defense systems that prevent most cosmic rays from reaching the ground. Compared to high-energy electromagnetic radiation, such as x-rays and gamma rays, cosmic rays may cause more severe damage to cells and are more likely to result in gene mutations or cancer. Scientists are now using animals to model the health effects of cosmic-ray exposure on humans.

To test how cosmic-ray exposure might affect the children of astronauts, Setlow and his collaborators used Medaka fish, which are small fresh-water fish native to Japan, South Korea, and China. The group exposed male Medaka to one of two types of high-energy nuclei - iron and carbon - that simulate cosmic rays. The iron-nuclei exposures were performed at Brookhaven’s Alternating Gradient Synchrotron facility, and the carbon exposures were carried out at the National Institute of Radiological Sciences in Chiba, Japan.

After exposure, the males were mated to non-exposed females. Fifteen to 20 embryos were collected daily for several months and observed under a microscope at the University of Tokyo. “Medaka fish were an excellent system to use for this study,” said Setlow. “Their biggest advantage is that the covering of their embryos is clear, allowing us to visually observe mutations within a few days of fertilization.”

The researchers looked for particular signs that the male Medaka - specifically, their sperm - had been damaged by the nuclei: dead embryos, which pointed to the presence of dominant lethal mutations, and color abnormalities, which indicated that a permanent, but not lethal, genetic change had occurred.

The group found that, in total, mutations resulting from exposure to iron and carbon nuclei occurred somewhat more frequently than mutations in fish exposed to gamma rays, which served as a control group. But within the total, dominant lethal mutations occurred far more frequently than color mutations. This indicates that sperm cells in male astronauts exposed to cosmic rays are more likely to die (causing temporary sterility) than undergo a non-lethal mutation that could pass on to children.

Source: Brookhaven National Laboratory

Explore further: Research investigates whether solar events could trigger birth defects on Earth

Related Stories

Rare find backs shape-shifting neutrino

March 27, 2013

Physicists announced further proof Wednesday for a theory that mysterious particles called neutrinos which go "missing" on the journey from the Sun to Earth are in fact shape-shifting along the way, arriving undetected.

Experiment examining a SLICE of the interstellar medium

December 14, 2012

(Phys.org)—When you look up at the stars at night, the space between stars looks empty. But, yes there is something there. It's called the interstellar medium. An experiment from the University of Colorado will fly on a ...

Recommended for you

Model shows how surge in wealth inequality may be reversed

July 30, 2015

(Phys.org)—For many Americans, the single biggest problem facing the country is the growing wealth inequality. Based on income tax data, wealth inequality in the US has steadily increased since the mid-1980s, with the top ...

The sound of music, according to physicists

July 30, 2015

Joshua Bodon is sick of hearing "Somewhere Over the Rainbow." More specifically, he's sick of hearing one 25-second clip of the song repeated more than 550 times.

Unusual red arcs spotted on icy Saturn moon Tethys

July 30, 2015

Like graffiti sprayed by an unknown artist, unexplained arc-shaped, reddish streaks are visible on the surface of Saturn's icy moon Tethys in new, enhanced-color images from NASA's Cassini spacecraft.

Power grid forecasting tool reduces costly errors

July 30, 2015

Accurately forecasting future electricity needs is tricky, with sudden weather changes and other variables impacting projections minute by minute. Errors can have grave repercussions, from blackouts to high market costs. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.