Exposure Science: Inhalation

Inhalation exposure increases the body burden of airborne pollutants, but since people spend more time indoors than outdoors, exposure is more closely correlated to indoor air concentrations. The air concentrations of many pollutants in the home, workplace, school, entertainment venues, and automobile are often higher than outdoors because even small emissions indoors lead to elevated concentrations due to the relative small volume of indoor venues. People's activities and consumer products can result in high gradients in air concentration near people further increasing inhalation exposure. Thus, it is necessary to combine the time spent and air concentrations in microenvironments encountered by people to develop exposure models or collect personal air samples to measure inhalation exposures rather than rely on modeling outdoor emissions or ambient monitoring. Advances in underlying exposure science principles have improved the understanding of inhalation exposure to individuals and population and have led to comprehensive approaches to determine aggregate and cumulative exposure. Approaches to reduce inhalation exposure should focus on where the highest exposure occurs; and as new personal and commercial products are introduced it is critical to determine how they will actually be used and the associated emissions to establish potential exposure and health risks, and remediation approaches.