TIMES OBITUARIES, June 27, 2002

 Dr Alice Stewart
 Epidemiologist who proved links between exposure to radiation and cancer,
 and forced the authorities into greater openness

 For more than 40 years the epidemiologist Alice Stewart challenged official
 estimates of the risks of radiation. Her research in 1956 and 1958 alerted
 the medical profession to the link between foetal X-rays and childhood
 cancer. Two decades later, in her seventies, she again called for a change
 in working practices when she published a study showing that workers at
 nuclear weapons plants are at greater health risk than international safety
 standards admit.
 She was born Alice Mary Naish in Sheffield in 1906. Her parents were both
 physicians and widely known for their dedication to children’s welfare.
 Alice took a medical degree at Cambridge, where she formed an intense
 relationship with the literary critic William Empson. Their friendship
 ended only with his death in 1984. But in 1933 she married Ludovick
 Stewart. They had a son and a daughter, but divorced in the early 1950s.

 During the war she studied the health risks of industrial chemicals in
 factories and among miners, and in 1946 she was one of the founders of the
 British Journal of Industrial Medicine. This first stage of her career
 culminated with her election as a Fellow of the Royal College of
 Physicians, the youngest woman to achieve this distinction. She already had
 a reputation as a brilliant teacher and clinician.

 Shortly after the war, she accepted a position under Professor John Ryle,
 at the new department of social medicine at Oxford, and became a Fellow of
 Lady Margaret Hall. Ryle hoped to direct the attention of the medical
 profession towards public health, and his ideals greatly appealed to
 Stewart, but with his death in 1949 social medicine at Oxford was demoted,
 and although she was kept on as a reader, she was left with “barely enough
 to light a gas fire”.

 Then, with a grant of £1,000, she launched her landmark study of the causes
 of childhood cancer. Beginning from a hunch that mothers might remember
 something that the doctors had forgotten, she devised a questionnaire for
 women whose children had died of any form of cancer between 1953 and 1955.
 By the time a mere 35 questionnaires had been returned, the answer was
 clear: a single diagnostic X-ray, well within the exposure considered safe,
 was enough almost to double the risk of early cancer.

 This news was a surprise to Stewart and was not welcome in the scientific
 community. Enthusiasm for nuclear technology was at a high point in the
 1950s, and radiography was being used for everything from treating acne and
 menstrual disorders to ascertaining shoe fit. X-rays, as Stewart put it,
 “were the favourite toy of the medical profession”. The British and
 American Governments were investing heavily in the arms race and promoting
 nuclear energy, and there was little willingness to recognise that
 radiation was as dangerous as Stewart claimed. She never again received a
 major grant in England.

 For the next two decades, however, she and her statistician, George Kneale,
 extended, elaborated and refined their database at what became the Oxford
 Survey of Childhood Cancer, until in the 1970s major medical bodies
 recommended that pregnant women should not be X-rayed, and the practice
 ceased.

 The Oxford Survey had collected information on hundreds of thousands of
 children across Britain over a 30-year period. Stewart and Kneale had
 demonstrated that children incubating cancer have greatly increased
 susceptibility to infections, and turned up a connection between
 inoculations and resistance to cancer which suggests links between cancer
 and the immune system. They also had theories about ultrasound and sudden
 infant death syndrome that they would have liked to test — but such funding
 as they had was cut off.

 In 1974, having officially retired and moved from Oxford to Birmingham,
 where she had accepted a research appointment, the 68-year-old Stewart
 received an unexpected phone call from America. Dr Thomas Mancuso, who had
 been at work on a government study of the health of nuclear workers at
 Hanford, the weapons complex that produced plutonium for the Manhattan
 Project, wanted her to “take a closer look” at his data.

 Mancuso’s study had been going on for more than a decade, and was not
 expected to turn up anything troubling, since workers’ exposure at Hanford,
 the oldest and largest nuclear weapons facility in the world, was well
 within the safety limits set by international guidelines. But Stewart and
 Kneale found that the cancer risk to the workers was about 20 times higher
 than was being claimed, a discovery that put them at odds with the
 multimillion-dollar Hiroshima and Nagasaki studies on which international
 safety guidelines are based.

 The American Department of Energy dismissed Mancuso and attempted to seize
 the data. But Stewart and Kneale took their work back to England and,
 together with Mancuso, published a series of studies which continued to
 corroborate a cancer effect considerably higher than the Hiroshima studies
 indicated. The Energy Department denied the scientists further access to
 the workers’ records and kept research under strict government control.
 Although the statistical methods of the study were criticised by the Oxford
 epidemiologist Richard Doll (who had been one of the first to prove the
 link between smoking and cancer), the Mancuso findings attracted public
 attention and provoked congressional investigations in 1978 and 1979.

 The accidents at Three Mile Island in 1979 and Chernobyl in 1986, while the
 British and American Governments were trying to expand nuclear facilities
 and weapons production, brought the anti-nuclear movement back to life, and
 Stewart became one of its heroes. She found herself much in demand, called
 on as an expert witness to testify against the siting of nuclear facilities
 and dumps and to testify in compensation cases by veterans and victims who
 had lived downwind of various plants.

 In 1986, when she was 80, she received the Right Livelihood Award, the
 “alternative Nobel” as it is called, which is awarded in the Swedish
 Parliament the day before the Nobel Prize to honour those who have made
 contributions to the betterment of society. The British Embassy, however,
 refused even to send a car to the airport to pick her up. In 1992 she was
 awarded the Ramazzini Prize for epidemiology.

 Even in the years when Stewart was making dozens of public appearances on
 behalf of activists in Britain and America, she always insisted that she
 was a scientist, not an activist, and that she did not have a political
 programme. She published more than 400 papers in scientific journals.
 However, although she could deliver her findings in person with exceptional
 clarity, her publications were often very hard to decipher.

 Also in 1986, Stewart received a $1.4 million grant to study the effects of
 low-dose radiation. This came not from a government agency or academic
 institute, but from activists, and derived from a fine imposed upon the
 Three Mile Island facility. To undertake the study, Stewart needed access
 to the nuclear workers’ records, but the American Government refused to
 release them. It took several years and several freedom of information
 suits to get at them. When in 1992 Stewart was finally granted access to
 the records of one third of all workers in nuclear weapons facilities in
 the US, the front page of The New York Times called it a blow for
 scientific freedom.

 Stewart continued to publish and present papers into her nineties. She was
 a charismatic speaker and a person of great warmth and generosity. She did
 not have an easy time as a lone woman in male-dominated fields, and she
 suffered keenly from the loss of funding and her isolation as a result of
 taking unpopular stances, but she maintained that obscurity had its
 advantages, since it allowed her to take risks that other scientists could
 not.

 “Truth is the daughter of time,” she was fond of saying; and “It helps in
 this field to be long-lived” — since in such a political area truth is slow
 in coming out. She lived long enough to see radiation science move in her
 direction, with each official estimate of radiation risk acknowledging
 greater danger than previous estimates admitted.

 She also lived to see her efforts help to break the American Department of
 Energy’s hold on radiation health research. She had the satisfaction of
 seeing one Secretary of Energy in 1993 open the record of the Government’s
 management of nuclear operations during the Cold War, including the records
 of human experimentation, and then seeing another in 2000 recommending
 compensation for nuclear workers suffering from cancers that may have been
 incurred at work.

 A biography of her, The Woman Who Knew Too Much by Gayle Green, was
 published in England and America in 1999.

 Alice Stewart is survived by her daughter.

 Alice Stewart, epidemiologist, was born on October 4, 1906. She died on
 June 23, 2002, aged 95.
 http://www.alicestewart.org/
 DEPLETED URANIUM