BIODOSIMETRY IN ASTRONAUTS (BIODOSIMETRY)
Research Area: Radiation Impacts on Humans
Expedition(s): 4, 10
Principal Investigator(s): ● Marco Durante, PhD, University Federico II, Naples, Italy
RESEARCH OBJECTIVES
It is known that DNA is damaged by ionizing radiation, which may lead to chromosomal
aberrations (ie, malfunction or malformation of chromosomes). This in turn could lead to
elevated risks of cancer and other disorders. Biodosimetry in Astronauts (Biodosimetry)
measures the frequency of chromosomal aberrations preflight and postflight from short-
duration mission space explorers.
RESULTS
To evaluate the possible alteration of cellular
response to ionizing radiation, extracted whole
blood was exposed to X-rays before and after the
mission. The previous data on chromosome
aberrations in peripheral lymphocytes of the same
astronaut after the Marco Polo mission in 2002
(Soyuz 4S / 3S exchange) showed a significant
increase in the yield of total aberrations. This
observation suggested a higher radio sensitivity of
lymphocytes when collected after flight compared
to preflight. However, this effect was not
reproduced during the Eneide mission in 2005
(Soyuz 10S / 9S exchange).Similar results were obtained after exposure to
gamma rays of blood samples of astronauts involved in short-duration missions. The results
suggested that intra-individual variations in radiation sensitivity can be significant, but they
cannot be related to the spaceflight. Follow-up data showed a reduced radio-sensitivity
compared to both preflight and postflight Marco Polo data. This may be seen as a result of an
increased resistance from repeat exposure or longer stay in space. This observation was
consistent with data reported in Russian cosmonauts, also showing evidence for a possible
acquired radiation adaptation. The yield of baseline chromosomal aberrations in the blood not
exposed on Earth was not modified after Marco Polo or Eneide, and this was consistent with
the low dose absorbed in these short-term space missions. However, while no significant
alterations were observed in metaphase samples, a slight increase was measured in premature
chromosome condensation (PCC). This may reflect the occurrence of slowly cycling aberrant
cells undetectable at mitosis and caused by the high-LET space radiation.
Multi-fluorescent chromosome map of a cell
exposed to cosmic radiation. ESA image.