Environment: History

London’s Killer Smog

Though air pollution was long recognized as a health hazard, it took outright catastrophes to prompt significant change. On a Friday in December 1952, a great fog blanketed London and mixed with the smoke from more than a million residential chimneys. By Saturday, visibility was at zero and transportation systems shut down. On Sunday, emergency services collapsed. By the time the air cleared on Tuesday, more than 4,000 had died, and the stage was set for the passage of Britain’s Clean Air Act of 1956.

Vitamin A

After observing how rats thrived when their diets included egg yolks or butterfat, Elmer V. McCollum isolated the nutrient he called “factor A”—now vitamin A.

Anna Baetjer

In 1924, a feisty young woman named Anna Baetjer joined the faculty just as governments were beginning to examine how conditions of daily life and work might make people ill. “A lot of people talked about it, and there was a lot of speculation… but nobody really knew… what happened inside the body,” Baetjer would later say. “It became clear we needed a lot of basic research.”

Baetjer, who in 1963 established a program in environmental toxicology, was one of the first scientists to positively correlate certain occupations to increased rates of disease. In particular, she drew indisputable links between lung cancer and exposure to chromium. Widely respected for her exacting lab and field work, she was “equally scornful of alarmist propaganda from self-styled ‘public interest’ voices and of disingenuous public relations on the part of industry,” the president of the National Association of Manufacturers noted after her death in 1984.