Organic solvents, such as acetone, TCE, and PCE, have the tendency to disperse quickly and widely when released into the air or water. Exposures to these chemicals can occur through contaminated drinking water, intrusion of vapor from groundwater into buildings, and inhalation and/or dermal contact with degreasing agents in the workplace. Because these chemicals are highly volatile and soluble in water, an intimate understanding of their physicochemical and fate-and-transport properties in the environment is needed to characterize exposure. For example, the intrusion of PCE vapor from groundwater into buildings is a complex process that is influenced by groundwater flow, soil type, and saturation of the soil layer, as well as building structure and ventilation.
Exponent scientists and engineers have estimated exposure to these chemicals under current-day conditions, and have reconstructed exposures based on historical conditions (i.e., exposure or dose reconstruction) for a number of projects. Examples include estimating exposures from inhalation of air in the workplace, contact with contaminated soils and surface water, and vapor intrusion into homes and office buildings. These projects typically involve multidisciplinary efforts to obtain relevant exposure information. We have developed site-specific studies to fill crucial data gaps, such as workplace surveys. To quantify exposures, we have applied or developed mathematical models that incorporate the best available scientific understanding of the behaviors of these chemicals.