Giant leap for mankind, but a deadly step for astronauts?
Space radiation could be to blame for high rates of heart disease among Apollo crews
LANDING a man on the Moon was undoubtedly a giant leap for mankind but for the individual men of the Apollo space programme it may have proved a death sentence.
Research from the US has found that astronauts who travelled into deep space on lunar missions were five times more likely to have died from cardiovascular diseases.
Eight astronauts of the 24 astronauts involved in Apollo’s space flights have since died, including Neil Armstrong, who died aged 82 following complications arising from heart bypass surgery in 2012. James Irwin of Apollo 15, who suffered a suspected heart attack on the Moon surface, died from cardiac arrest in 1991, as did Ronald Evans of Apollo 17 in 1990.
Astronauts are fitter than the general population and have access to the best medical care. Those of comparable age but who never flew, or only achieved low Earth orbit, had less than a one in 10 chance of death from cardiovascular disease. But the chance of death rose to 43 per cent for those who reached the Moon or deep space, probably because of the impact of deadly space radiation.
“We know very little about the effects of deep space radiation on human health, particularly on the cardiovascular system,” said Prof Michael Delp, dean of Florida State University’s College of Human Sciences.
“As multiple spacefaring nations contemplate extended manned missions to Mars and the Moon, health risks could be elevated as travel goes beyond the Earth’s protective magnetosphere into the more intense deep space radiation environment.”
The Apollo programme ran from 1961 to 1972, with 11 manned flights into space between 1968 and 1972.
Researchers already feared that high levels of cosmic radiation could cause cancer or Alzheimer’s. Apollo 14’s Alan Shepherd died of leukaemia in 1998 while Apollo 13’s Jack Swigert also died of cancer in 1982.
The latest study, published in Scientific Reports, was the first to look
‘As multiple nations contemplate manned missions to Mars, health risks could be elevated’
at the mortality of all Apollo astronauts and make the link to heart health. It is thought that space radiation can severely damage blood vessels in the heart leading to long-term weakening.
The longest mission, Apollo 17, only spent three days on the Moon, so it is feared the damage could be far worse during longer programmes.
Prof Delp and his colleagues also exposed mice to the type of radiation that Apollo astronauts would have experienced. After six months — the equivalent of 20 human years — the mice demonstrated an impairment of arteries that is known to lead to the development of atherosclerotic cardiovascular disease in humans.
The new research throws into doubt plans for future Moon bases or colonies on Mars unless researchers can find a way to shield space travellers from the deadly radiation.
Dr Dorit Donoviel, head of the National Space Biomedical Research Institute, said there were many physical problems associated with long-term space flight, including radiation exposure, visual impairment syndrome and the fact that the immune system would be compromised.