Study suggests space travelers are not yet at greater risk of dying from cancer or cardiovascular disease
A team of researchers with Mortality Research & Consulting, Federal State Budgetary Scientific Institution Izmerov Research Institute of Occupational Health and the Russian State Research Center has found that thus far, astronauts and cosmonauts are not at increased risk of dying from cancer or cardiovascular disease (CVD) due to radiation exposure during their space adventures.
Throughout the history of space flight, scientists and astronauts have known that space travel entails an increased risk of cancer or CVD—with less protection from the sun's radiation, exposure levels rise. Space engineers in the U.S. and Russia have added as much protection as possible to spacecraft and spacesuits, but have assumed that those going into space face increased health risks. In this new effort, the researchers sought to test that assumption—more specifically, to find out if space travel has resulted in early deaths.
To learn more about the impact of space travel for cosmonauts and astronauts, the researchers reviewed the medical histories of all astronauts and cosmonauts that conducted space missions over the years 1959 to 2018, which covered almost all of the history of human space flight. In all, that included 117 cosmonauts and 301 astronauts. In so doing, they found that 89 have died. They also found that 75 percent of the deaths of the cosmonauts were due to cancer or heart disease. For astronauts, the number was 50 percent. More specifically, they found that 30 percent of the astronauts died from cancer, and under 15 percent from CVD. For the cosmonauts, the numbers were 28 and 50 percent.
The researchers report that none of these statistics stand out, but more importantly, they were not able to find any linkages between flying in space and incurring the expected increased risk of cancer or CVD. They acknowledge that their findings have little bearing on future missions to Mars, because all but 24 of the space travelers in their study never left the safety of the Earth's magnetic field. And the 24 astronauts who did—those who traveled to the moon and back—are too small a cohort to provide meaningful statistics.
More information: Robert J. Reynolds et al. Contrapositive logic suggests space radiation not having a strong impact on mortality of US astronauts and Soviet and Russian cosmonauts, Scientific Reports (2019). DOI: 10.1038/s41598-019-44858-0
Journal information: Scientific Reports
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