Abstract

PIP: In an issue of the American Journal of Epidemiology highlighting the challenges of studying disease risks associated with low-dose environmental exposures, author John Snow was described giving an expert-witness testimony on behalf of industry. It is noted that emanations from the bone-boiling factories were not causing ill health in the community at large. This statement invoked arguments that are often raised when unexpected health effects are encountered following supposed low-dose exposures. In addition to this historical report of John Snow, the issue of the Journal features articles that illustrate various aspects of the difficulties faced in studying health effects of environmental exposures. Several of these issues include innovative attempts to improve the quality of such research. Moreover, these articles demonstrate that technological advances are making possible a wide range of innovative study designs and strategies to better assess both exposures and outcomes.