The general public is repeatedly in contact with time-varying amounts of environmental chemicals in air, water, food, and soil. On a daily basis, individuals are exposed in a variety of microenvironments that correspond to the daily activities that place persons in contact with environmental chemicals (e.g., soil contaminants during gardening, lawn chemicals during and following application, in-transit exposures to benzene from gasoline, environmental tobacco smoke [ETS] in residences and office buildings, volatile organic compounds [VOCs] from consumer products used in the residence). In response to the need to characterize multiple chemical exposures from multiple environmental media (e.g., soil, air, food, water), a number of ongoing efforts have been undertaken to develop methodologies to aid in quantifying these exposures (McKone 1991, Cal-EPA 1994).
