On a Wednesday morning nearly 50 years ago, a heavy smog settled on the Pennsylvania town of Donora. At first, residents simply remarked on a few sore throats. By Friday, however, hundreds of people were seriously ill. By Sunday, 19 were dead.
Such smog disasters helped persuade the government to start controlling air pollution. Federal laws were passed—most notably the 1970 Clean Air Act—and as a result many people now assume that death by smog is a thing of the past.
Not quite. Some pollutants are safely under control, but others are still killing, according to the Environmental Protection Agency, which this past year proposed to tackle them. The worst are fine particulates—grit and chemicals that travel deep into the lungs. By aggravating heart and lung disease, says the epa, fine particulates contribute to 60,000 deaths a year in the United States. Two large health studies reviewed by the agency ...
