Criteria air pollutants and toxic air pollutants

This review presents a brief overview of the health effects and exposures o f two criteria pollutants-ozone and particulate matter-and two toxic air po llutants-benzene and formaldehyde. These pollutants were selected from the six criteria pollutants and from the 189 toxic air pollutants on the basis of their prevalence in the United States, their physicochemical behavior, a nd the magnitude of their potential health threat. The health effects data included in this review primarily include results from epidemiologic studie s; however, some findings from animal studies are also discussed when no ot her information is available. Health effects findings for each pollutant ar e related in this review to corresponding information about outdoor, indoor , and personal exposures and pollutant sources.