Cardno ChemRisk evaluated the potential pathways of exposure to metals and radionuclides and assessed the risk, if any, posed to residents that lived near where the product was used. A risk assessment for a theoretical person that lived directly on soil comprised entirely of the beneficial CCR product determined that exposure would pose no health threat to the residents. For the risk assessment, the concentrations of metals in the CCR product were compared to residential soil screening levels and then to background soil concentrations.
Only arsenic, cobalt, manganese, and vanadium concentrations were above the USEPA residential soil screening levels and concentrations of cobalt, manganese, and vanadium were below background soil concentrations. Exposure to arsenic was evaluated further and after consideration for the limited oral bioavailability of the CCR product, the risk assessment concluded that there were no unacceptable risks to residents.
The risk assessment of the radionuclides was published in the peer-reviewed scientific literature (Towle et al., 2018).
Cardno ChemRisk staff provided a full risk assessment and evaluation of potential pathways for coal combustion residuals, determining they posted no health threat to residents living near landfills.