When Dr. Janette Sherman was practicing internal medicine in suburban Detroit in the 1970s, she noticed that several of her patients were reporting similar symptoms, and that they all worked in automobile factories.

She soon realized that they were all being exposed to the same hazardous chemicals, including arsenic. She shared her findings with the consumer activist Ralph Nader’s Health Research Group, and in 1973 they issued a report on the health of 489 Detroit autoworkers.

Their jobs, the report said, were “associated with increased amounts of chronic bronchitis, chronic obstructive lung disease, or other disabling and killing diseases.”

A key finding was that nonsmokers had just as much chronic illness as smokers. The nonsmokers also had a 50 percent greater chance of developing those diseases than nonsmokers whose jobs did not expose them to the dust, smoke, fumes, chemicals and exhaust from forklift trucks to be found in factories. Such diseases had previously been attributed to cigarettes.