US EPA

Why should exposure analysts be interested in personal exposure to ambient PM as opposed to total personal exposure to both ambient and nonambient PM? The National Ambient Air Quality Standards for PM are based largely on epidemiologic studies that find a statistical association between daily PM concentrations, measured at a stationary outdoor air monitoring site, and daily health effects. The NRC felt that In order to make responsible decisions about the level of the National Ambient Air Quality Standards (NAAQS) for PM, EPA needed to know the qualitative and quantitative errors resulting from the use of ambient PM measurements as a surrogate for total personal exposure.

Wilson Jr., W E. Impact Of Ambient PM On The Indoor Environment And Personal Exposure. Presented at Research Priorities for Airborne Particulate Matter, Charleston, SC, November 9, 2001.