Personal exposure to respirable particulates and sulfates.

Measurements of personal exposure to respirable particulates and sulfates were made by 37 volunteers in Watertown, MA and Steubenville, OH. These measurements were compared with simultaneous measurements of outdoor ambient concentrations and measurements in the homes of the participants. Over the large range of outdoor concentrations measured, our limited sample showed that, mean personal exposure for each city was related to the mean outdoor levels for the city. Within each city, however, individuals have markedly different exposures based on their activities. A timeweighted indoor/outdoor activity model gives improved estimates of exposure. However, the model only modestly improves estimates of personal exposures over those predicted from measured indoor concentrations alone.