Exposure modeling and risk assessment at a water pollution control plant

This study utilized tracer gas methods, influent source analysis, and simulation techniques to develop a method for predicting air concentrations of volatile organic compounds (VOCs) in a barscreen room at a water pollution control plant. Water pollution control plant workers are potentially exposed to numerous VOCs during routine tasks including wastewater sampling, equipment maintenance, and cleaning. Since air concentrations of VOCs within the barscreen room are assumed to be related to the VOC loading of the wastewater, exposures are expected to be variable. Due to the limitations of plant staff, limited resources, and the large number of sampling days required to adequately characterize exposures, traditional industrial hygiene monitoring methods were not judged to be feasible for exposure evaluation. This study incorporated source analysis and Monte Carlo simulation techniques to address the variability and uncertainty associated with the air contaminant emissions and to evaluate the risks associated with exposure to this area of the plant. The study was successful in developing a method for estimating barscreen room air concentrations of dissolved VOCs.