气候变化领域集成服务门户

Using the United States Environmental Protection Agency's (U.S. EPA) Multimedia, Multi-pathway, Multi-receptor Exposure and Risk Assessment (3MRA) technology, a computer-based biosolids groundwater risk characterization screening tool (RCST) was developed. The objective of this study was to apply the RCST to characterize the potential human health risks associated with exposure to biosolid pollutants. RCST application to two Virginia biosolids land application sites predicted that pollutant concentrations as large as ten times the current regulatory limit could be safely applied to land with no apparent human health effects associated with groundwater consumption. Only under unrealistically high biosolids application rates and pollutant concentrations were the public health risks associated with groundwater impairment characterized as significant (hazard quotient. 1.0). For example, when the biosolids land application rate was increased to 900 Mg/ha and the pollutant concentrations were increased to ten times the legal limit, the hazard quotient value ranged from 1.27 (zinc) to 248.19 (selenium).