Genesis of Eden
Living Dangerously
New Scientist 28 Feb 98
YOUNG children and old people around the world could be exposed to damaging doses of radiation from nuclear plants and other sources because the database that is used to set safe limits is flawed. A new analysis by a leading British epidemiologist suggests that the young and old are more sensitive to radiation damage than was previously thought. The international system of radiation safety limits is mostly based on epidemiological studies of 76 000 people from Hiroshima and Nagasaki who were still alive five years after their cities were obliterated by American atom bombs in 1945. The rates at which they have contracted cancers compared with people from other Japanese cities are used by regulatory agencies to estimate the risks of exposing people to radiation from nuclear plants, bomb tests and fallout from accidents such as that at Chernobyl in 1986. But Alice Stewart, famous for her work in the 1950s revealing the dangers of X-raying pregnant women, argues that the atom bomb survivors are not a normal, homogeneous population. She says her analysis shows that children and old people are more vulnerable to radiation, and that a high proportion of them died between 1945 and 1950 before studies of the Hiroshima and Nagasaki residents began. The young and old are therefore under-represented among the survivors. "The atom bomb data are no good as a basis for radiation safety regulations," she says.
Aged 91, Stewart is an honorary professor
at the University of Birmingham School of Medicine. Her study,
which is due to be published by the Scientific and Technological
Options Assessment unit of the European Parliament in the next
few weeks, compares 2601 survivors who suffered from acute radiation
injuries with 63 072 survivors who did not. Stewart found that
of those with acute injuries, children who were under 10 when
the bombs exploded were a thousand times as likely to die of cancer
as people aged between 10 and 55. People over 55 at the time of
the explosions were twice as likely to die of cancer as those
aged between 10 and 55, the study shows. Among those who did not
suffer acute injuries, children under 10 at the time of the explosions
were three times as likely to die of cancer as other age groups.
Stewart says her results show that the very young and very old
are particularly sensitive to radiation. She suggests that the
immune systems of the young and old are more easily harmed because
they are either still developing or are breaking down. A damaged
immune system makes people more vulnerable to cancers and infections,
she says. The National Radiological Protection Board, which advises
the British govemment, accepts that the Japanese database is not
perfect because it lacks information on the first five years of
exposure. But the board's spokesman, Mike Clark, points out that
safety limits are also derived from other databases-including
Stewart's earlier work on X-rays. Rob Edwards
Bomb Damage New Scientist 4 Apr 98
UP TO 40 per cent of the British soldiers who watched nuclear weapons tests in the 1950s now suffer from a rare and debilitating skin and bone disease, a controversial new report claims. It warns that the veterans' children and grandchildren may inherit the disease-and are also more likely to develop spina bifida. More than 21 000 members of the British armed forces witnessed 46 nuclear explosions in the atmosphere in Australia and the Pacific between 1952 and 1962. Although many veterans believe their exposure to radiation made them ill, successive British governments have refused to grant them compensation. Two studies commissioned by the Ministry of Defence in 1988 and 1993 concluded that the veterans suffered no increase in cancer risk. The veterans have criticised the studies and have appealed to the European Court of Human Rights in Strasbourg, which is expected to issue its verdict in May (This Week, 8 February 1997, p 4). Sue Rabbitt Roff of Dundee University has analysed the illnesses reported by 1041 British and 235 New Zealand test veterans. More than 500 suffer from skin problems, arthritis in the chest and gastrointestinal conditions that she says are consistent with a syndrome called Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO), first described in Japan in the late 1960s. The SAPHO syndrome, which has never before been linked to radiation and for which there is no known single cause, is extremely rare. Roff's research, which veterans have submitted as evidence to the European Court, suggests that up to 40 per cent of the 5125 children and grandchildren of the veterans may also have the same group of illnesses. "There is a specific syndrome of conditions which may have been triggered by these men's exposure to radiation in their early twenties and which unfortunately seems to be heritable," she says. Roff believes that radiation could have harmed the veterans' immune systems, rendering them more vulnerable to the SAPHO syndrome. It could also, she claims, have caused genetic damage to the veterans'sperm. Among the 2261 children of British veterans, she found 15 victims of spina bifida, a congenital deformity of the spine caused by a neural defect. She contrasts this to the 2 to 3 cases per 1000 live births found in the general population. Roff is due to report her findings to the annual meeting of the British Institute of Radiology in Birmingham in June. Her work is likely to create controversy. Government scientists who have studied the veterans are sceptical of her conclusions. "We are awaiting the publication of her work in a peer reviewed journal," says a spokesman for the National Radiological Protection Board. Others, however, are not so dismissive. Riitta Myllykangas, an arthritis expert from Ktiopio University Hospital in Finland, says it is possible that the arthritis that forms part of the SAPHO syndrome is triggered by radiation damaging stem cells in bone marrow. Rob Edwards