[3][4] In the early 1960s, Ferris and colleague Donald O. Anderson carried out the first large-scale statistical study in the United States linking cigarette smoking to respiratory disease.
[6][7] This became the Harvard Six Cities study, a landmark piece of public health research that helped to prove the link between fine-particulate air pollution and higher death rates when it was published in 1993.
[1][9] Ferris' first few scientific papers, all concerning heat exchange and blood flow in the human hand, were published in 1946,[10] and he returned to Harvard School of Public Health as a research fellow in physiology in 1948.
[5] The study, published in The New England Journal of Medicine in 1962, showed that the heaviest smokers had 4.4 times the risk of developing chronic respiratory disease compared to nonsmokers.
[17] Ferris and Donald Anderson carried out a number of other "community" studies using an approach pioneered by the British researchers, which combined interview questionnaires with simple tests of lung function.
[25] In the mid-1960s, Ferris and Harvard colleague Frank E. Speizer studied chronic respiratory disease in road workers in Boston's Sumner Tunnel.
[35][36] Ferris also explored the effects of industrial plants on the respiratory health of people in nearby communities,[37] and the potential environmental hazards of electromagnetic radiation.