ROBERT KEHOE. From the darkness it can be difficult to determine the source of a shadow. Dr. Robert Kehoe of the Kettering Laboratory cast such a shadow over us all, one of the darkest of the modern era.

For more than sixty years Americans breathed hundreds of thousands of tons of raw poison wafted into the atmosphere from leaded gasoline. This toxic air contributed to a medical toll of some 5,000 annual deaths from lead-related heart disease and an almost incalculable toll of tragedy in the neurological injuries and learning difficulties imposed on children. One estimate, based on government data, suggests that from 1927 to 1987, 68 million young children in the United States were exposed to toxic amounts of lead from gasoline, until the additive was finally phased out in the United States.

For this in good measure we can thank Dr. Kehoe. Kehoe preached the gospel of leaded gasoline's safety from his pulpit at the Kettering Laboratory for the duration of his scientific career. Kehoe did much the same for fluoride, with health consequences of a potentially similar magnitude.

FRANK SEAMANS. A top lawyer for Alcoa, Seamans was also head of the group of senior attorneys known as the Fluorine Lawyers Committee, which represented big corporations in cases of alleged industrial fluoride pollution.

FRANCIS FRARY. As Director of Research at the Aluminum Company of America from 1918, Frary was one of the most powerful science bureaucrats in the United States and grappled with the issue of fluoride emissions from aluminum smelters. It was Frary who made early suggestions to Gerald Cox, a researcher at the Mellon Institute, that fluoride might make strong teeth.