At age 65, a time in life when most people are winding down and spending life recalling past accomplishment, Judson Wells started a new career after retiring as chemist and then executive at Dupont Chemical Company. This PhD in chemistry (Harvard undergraduate 1938 and PhD 1941) started working on lung cancer and secondhand smoke issues from his home in Kennett Square, Pennsylvania, as a volunteer for the American Lung Association. In retirement, Jud Wells became one of the most influential—if not widely recognised—epidemiologists in the world on the issue of secondhand smoke.

He published the first comprehensive estimate of the deaths due to secondhand smoke in his landmark 1988 paper in Environment International.1 He was the first person to highlight the connection between passive smoking and heart disease. While very controversial at the time, the conclusion that secondhand smoke causes heart disease was a central new health conclusion in the 2006 Surgeon General’s report2 18 years later.

Jud’s work on heart disease had a major effect—it demonstrated clearly that heart disease—not lung cancer—was the main source of premature death from passive smoking exposure. His 1988 paper estimated that passive smoking was causing 50 000 deaths per …