Tony Stefani used to be a firefighter and a cancer patient. The two, he believes, had something to do with each other.

Stefani was a firefighter in his native San Francisco for 28 years, nearly half of them as captain of a rescue squad.

But the profession he loved may have nearly cost him his health. The job involved breathing all kinds of substances, from the diesel fumes of fire engines to smoke laced with flame retardants in people’s homes…

Stephanie M. Lee