John Snow, the Broad Street pump, and the precautionary principle

“John Snow, the Broad Street pump, and the precautionary principle”
Article by Bernard D. Goldstein

In 1854 John Snow was responsible for a major advance in environmental health science when he demonstrated that cholera epidemics were waterborne rather than airborne. By mapping the disease outbreak he identified a specific London water source, the Broad Street pump, as its proximate cause. Removal of the pump handle was temporally related to the end of the epidemic. For his very careful mapping of an epidemic resulting in a new understanding of the cause of disease, John Snow is considered to be the father of the science of epidemiology.

More recently, many who advocate the precautionary principle have adopted this historic event as paradigmatic of action taken under precaution. They point out that Snow\'s efforts occurred before the identification of the cholera microbe or an understanding of the germ theory of disease. Snow\'s example seems to demonstrate that it is important to act on the possible association of a cause with an effect without a theoretical underpinning for the association and in preference to obtaining the scientific information needed to appropriately inform the decision.

In contrast, Goldstein argues that Snow, an accomplished inhalation toxicologist, used his basic science knowledge to discard the erroneous associations that had previously led to the belief that cholera was an airborne disease. Snow\'s action is in many ways the antithesis of a precautionary approach in that his rigorous science overturned mistaken and harmful conclusions about the cause of cholera, which had been based on well documented but non-causal associations.

Read the entire Elsevier Environmental Development journal article.

Goldstein, former dean of GSPH, is an environmental toxicologist with research interests focusing largely on the concept of biological markers in the field of risk assessment. He is professor of environmental and occupational health at GSPH and served as the interim director of the Center for Healthy Environments and Communities (CHEC). He is author of more than 150 peer-reviewed publications related to environmental medicine.

Goldstein\'s past experience includes an appointment as assistant administrator for research and development at the U.S. Environmental Protection Agency and the accomplishment of being the founding director of the Environmental and Occupational Health Sciences Institute, a state university program that responded to environmental issues in New Jersey. He is an elected member of the Institute of Medicine of the National Academies. Goldstein has been president of the Society for Risk Analysis and a member or chair of numerous federal and World Health Organization committees, including chair of the National Institutes of Health Toxicology Study Section and EPA\'s Clean Air Scientific Advisory Committee.

Learn about events related to this year’s GSPH One Book One Community exploration of The Ghost Map by Steven Johnson, a book about the 1854 London summer that shaped the world in which we now live.


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