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Modeling Tribal Exposures to PCBs from Fish Consumption
Citation:
Xue, J. AND V. Zartarian. Modeling Tribal Exposures to PCBs from Fish Consumption. ISES Annual Meeting, Henderson, NV, Henderson, NV, October 18 - 23, 2015.
Impact/Purpose:
The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
Description:
Studies have shown that U.S. population continues to be exposed to polychlorinated biphenyls (PCBs), despite the ban ~40 years ago. Fish intake is a major pathway, especially, for high fish-consumption groups. Exposure assessment and risk management considerations for tribal fish consumption are different from that for the general U.S. population because of higher fish intake from subsistence fishing and/or from unique cultural practices. This research summarizes analyses of available data and methodologies for estimating tribal exposures to PCBs from fish consumption. Large scale fish tissue concentration data sets from the Environmental Protections Agency’s (EPA’s) Office of Water, USGS’s EMMMA program, and other data sources, were integrated, analyzed, and combined with tribal fish intake data for exposure analyses using EPA’s SHEDS-Dietary model from SHEDS-multimedia. SHEDS-Multimedia is a physically-based, probabilistic model, that can simulate cumulative (multiple chemicals) or aggregate (single chemical) exposures over time for a population via residential and dietary routes of exposure for a variety of multimedia, multipathway environmental chemicals. SHEDS was used to integrate PCBs concentrations in fish tissue, fish consumption data, and other data to estimate the dietary exposures. Contribution analyses indicates that length of fish, fish types, and fish lipid percentage are major contributors to PCBs concentrations in fish tissue. Sensitivity analyses identify key variables and exposure pathways. Our results show that PCBs exposure of tribal populations from fish consumption are about 5 to 15 times higher than the U.S. general population and that those exposures pose potential health risks. These exposure assessment methods and tools can help inform decisions regarding meal sizes and frequency, types of fish and water bodies to avoid, and other factors to minimize exposures and potential health risks from contaminated fish in tribal fields.
