Air pollution in the United States as a problem affecting health, as well as man's enjoyment of his property, was first noted in 1912 in the reports of the investigators at the Mellon Institute of the University of Pittsburgh. The Selby copper smelter incident in 1915 was among the first episodic air pollution events documented. The US Public Health Service studied carbon monoxide buildup in vehicular tunnels in 1928 and 1929. the Donora (Pennsylvania) pollution episode, where 17 people died, occurred in 1949. It and the onset of smog conditions in the Los Angeles area really initiated broad public awareness of air pollution as a public health hazard in the USA. The symptoms of air pollution-related injuries are discussed, the role of the US Public Health Service in dealing with air pollution, and the effect of the Clean Air Act of 1963 are discussed. 26 references.