One of the aims of publishing accounts of the history of important events in occupational and environmental medicine, by those who were involved, is to acquaint the newcomer to this field with the considerations and the consequences of participating in controversy at first hand. Authors, whose contributions have been solicited for the series in this journal under the general heading "Historical Perspectives in Occupational Medicine," have responded in several ways. Some have produced accounts in which one must read imaginatively between the lines to get any suspicion that the path of scientific enquiry ran other than smooth. Some, even after the interval of several decades, either have found the process of recollection too painful to contemplate, or having felt able to contemplate recounting in tranquility their experience, in the event have found the process more difficult than they had anticipated. The wounds and scars received by advocates of unpopular opinions, and by persons publishing reports of adverse effect that are "inconvenient," in terms of their personal health and professional careers, are real but rarely presented in scientific journals. It is reassuring to discover that despite the undoubted casualties, it is possible for a number of scientists to survive professionally despite the vicissitudes of airing honest doubt and publishing early reports of hazard.
In this issue, one of the important contributors to the ionizing radiation doseresponse data base and to its interpretation, Alice Stewart, describes her and her colleagues Mancuso and Kneale's involvement in the debate [1991]. The tone of her account is low key and will disappoint those who prefer the more highly spiced Hanford Works, Richland, Washington, was one of the largest atomic plants in the United States. Several tens of thousands of persons employed at that site have been followed over four decades. Impressive as this number may seem at first sight, the Mancuso/Stewart/Kneale team consider it too small to estimate a cancer risk even 10 times as large as the low level radiation estimate produced by the International Commission on Radiation Protection [Stewart and Kneale, 19811. It has been estimated [Stern, 19811 that a population 10-100 times the size would be required, even employing sophisticated techniques of analysis.