QuantAQ

EPA’s Human Exposure Model (HEM) is a probabilistic exposure assessment tool used to estimate how people are exposed to contaminants (often air pollutants, but not limited to them) through different pathways and microenvironments. It is designed to support human health risk assessments by translating environmental concentrations into population exposure distributions for specific pollutants, locations, and demographic groups. HEM uses information on contaminant levels, population characteristics, and time–activity patterns to produce quantitative estimates of average and high-end exposures suitable for regulatory analyses and comparative policy evaluations.