Harvard Six Cities study

The Harvard "Six Cities" study was a major epidemiological study of over 8,000 adults in six American cities that helped to establish the connection between fine-particulate air pollution (such as diesel engine soot) and reduced life expectancy ("excess mortality").^[1] Widely acknowledged as a landmark piece of public health research,^[2][3][4] it was initiated by Benjamin G. Ferris, Jr^[5] at Harvard School of Public Health and carried out by Harvard's Douglas Dockery, C. Arden Pope of Brigham Young University, Ferris himself, Frank E. Speizer, and four other collaborators, and published in the New England Journal of Medicine in 1993.^[1] Following a lawsuit by The American Lung Association, the study, and its various follow-ups, led to a tightening of pollution standards by the US Environmental Protection Agency. This prompted an intense backlash from industry groups in the late 1990s, culminating in a Supreme Court case, in what Science magazine termed "the biggest environmental fight of the decade".^[6][7]