The Woman Who Knew Too Much: Alice Stewart and the Secrets of Radiation (review)

Gayle Greene. The Woman Who Knew Too Much: Alice Stewart and the Secrets of Radiation. Ann Arbor: University of Michigan Press, 1999. x + 321 pp. Ill. $35.00; £19.95.

For the past twenty years, most American and British obstetricians have avoided taking routine X rays of patients who are pregnant. In dental offices, at least in the United States, no one is X-rayed without first donning a protective apron extending from shoulders to knees. These precautions are the result, at least in part, of research performed by the British physician and epidemiologist Alice Stewart (b. 1906). Gayle Green's lively biography traces the life of Dr. Stewart, principal discoverer of the link between in utero X-ray exposure and the development of childhood leukemia.

As an unexpected consequence of her work on leukemia, Stewart became a leading critic of the nuclear-power industry's worker-safety standards. Greene's book is an openly partisan account of Stewart's struggles to win acceptance for her claim that even low-dose radiation exposure is a health hazard; it is also, incidentally, a case study of the effects of gender discrimination on women physicians' careers in twentieth-century England. The book will surely make Stewart better known among the general public, but Greene's black-and-white portrait of Stewart's uphill fight does not do justice to her subject (and neither does her irritating habit of referring to Stewart by her first name).

Alice Stewart was the daughter of two Sheffield physicians. Her father's elevation to the status of consultant physician forced her mother into semiretirement (apparently an English version of the antinepotism laws), until a wartime opening at the Sheffield Medical College allowed her to become an anatomy tutor. In Stewart's later career as an epidemiologist, she faced many of the same gender-linked career hazards as her mother. But for her first decade in practice, an exceptional academic record at Cambridge and a desirable clinical clerkship at the Royal Free Hospital in London prevented her being shunted to the professional backwaters. Indeed, despite an early marriage and the birth of two children, she seemed on her way to a prestigious consultant's career in London.

The work for which Stewart is remembered really began in 1945 when she was invited to become the assistant to Dr. John Ryle, the founder of British academic social medicine, at the new Institute for Social Medicine at Oxford. With prudent mentoring by Ryle, Stewart might have risen to a position of academic prominence. She was, after all, doing pioneering work in a relatively new field. Unfortunately, Ryle died only a few years later, leaving his assistant to fend for herself--an underfunded, self-taught maverick. The work she produced during these years, the linkage of childhood leukemia to prenatal X rays, came to be known as the Oxford Survey of Childhood Cancer and was published in 1958. Because Stewart's findings implicitly called into question a widely accepted study of radiation exposure hazards, the Atomic Bomb Casualty Commission (ABCC) report, they were challenged immediately. One reason was her unconventional methodology: instead of the prospective studies then considered the only acceptable starting point for public health surveys, she began with interviews of matched pairs of mothers of children with and without childhood cancer. This retrospective approach, with its risk of observer bias, made the study a ready target for defenders of the ABCC, which had concluded that exposure to ionizing radiation carried little or no risk below a precise threshold of exposure. Although Stewart's results are now widely accepted, it took another twenty years--and a corroborating study by another research team--for the Oxford Survey's findings to carry the day.

From about 1970, Stewart turned her attention to the underlying issue raised by her work: the serious underestimation, in her...