The World Health Organization estimates that worldwide more than 2 million people die each year from outdoor air pollution.Recent articles published in Lancet on the Global Burden of Disease show that Indoor and outdoor air pollution both rank in the top ten causes of mortality attributed to all factors including disease,infections,poor diet,poor water quality,etc.This talk will present a history of air pollution,providing examples of past air pollution disasters that stimulated the formation of air pollution standards in the United States and Europe.It will discuss how these standards have continued to evolve as recent and current research has more precisely defined concentrations that are harmful,and populations that are particularly susceptible to air pollutants,as well as contrast health effects associated with both acute and chronic exposure to air pollutants.It will also describe some potential biological mechanisms by which air pollution can kill people.Air pollution standards have resulted in decreased air pollution levels in the United States over the past several decades.These improvements in air quality have resulted in decreased morbidity and mortality.This abstract of a presentation does not necessarily reflect EPA policy.