Radiation exposure in space would not have a significant impact on the causes of astronaut deaths, according to US researchers. More than half a century of history has spoken: from the beginning of space exploration, in the 1960s to the present day, astronauts remain the cream of the crop for health, explain the researchers.
Astronauts’ mortality from cardiovascular disease or cancer is no higher, despite increased exposure to radiation, according to US researchers Robert Reynolds and Steven Day of Mortality Research & Consulting, Inc. Their study, published in the journal Occupational & Environmental Medicine, compared the health of NASA astronauts and professional athletes, from the beginnings of the space conquest to the present day.
Indeed, the job of astronaut, like that of high level athlete, is not within the reach of anyone. Only a handful of 12 candidates were selected by NASA for its 2017 promotion, while 18,300 had come forward. This careful selection keeps only the most physically and mentally fit, which means that astronauts are a minority of people in better health than the general population. Hence the need for researchers to find a group of individuals of equal level of good health, but who never had to work in space, to serve as witnesses. Thus the comparison with high level athletes
The researchers compared astronaut mortality to that of the NBA and Major League Baseball players between January 1960 and May 2018. These athletes look like astronauts “on many important aspects, except that they have never been to space,” Robert Reynolds tells Reuters. They therefore reflect the state of health of astronauts as if they “had a comparable job” but remained all their lives on Earth.
This approximation avoids what is known in statistics as “a healthy worker effect”: the fact that studies of mortality, morbidity, use of care, or cost of health care derived only from a population of adult workers cannot be generalized to the population at large, because those who are working are, on the whole, healthier than those who are not.
Researchers have found that astronauts, like professional athletes, have lower mortality than the general population. There are, however, some differences in the causes of death, with astronauts more likely to fall victim to external factors, such as accidents, and less likely to succumb to cardiovascular disease and other natural but premature causes.
These results indicate that radiation exposure generally has not led to premature deaths from heart disease or cancer among astronauts. “We believe that cardiovascular health is the most important factor in their longevity,” says Robert Reynolds, who points out that limited data can not be categorical. The study only deals with NASA astronauts of the male sex, ie less than 300 people.
While government or private space agencies dream of the first Man on Mars in the 2030s, this study seems auspicious. But beware however of hasty conclusions. It does not mean that space travel is safe, because until now, astronauts from the Apollo missions to the moon and the ISS crew have been subjected to “low radiation”, comments Reuters Francis Cucinotta, radiation specialist at the University of Nevada, who is not involved in the study. “The dose will be 50 to 100 times higher for a mission to Mars. “