Modelling human exposures to air pollution control (APC) residues released from landfills in England and Wales

Abstract

Human exposures to air pollution control (APC) residues released from 6 landfills were modeled and assessed. Following a qualitative risk characterisation, direct and indirect exposures were quantified. Site-specific air dispersion modelling was conducted for PM10, PCDDs/PCDFs, Pb, Cd, As and CrVI concentrations at the closest residential points of exposure for 4 landfill sites accepting, in total, 75 %w/w of the APC residues disposed of in 2000-2001 (UK). Inhalation risks, assessed by reference to air quality standards at residential exposure points were assessed as insignificant. Preliminary modelling suggested that indirect exposures from PCDDs/PCDFs at the 95th percentile level for the site where APC deposition rates were highest, exceed the tolerable daily soil intake (TDSI) but warrant further study given model limitations. These results offer an initial screen of the significance of potential risks from APC disposal, which is of value in addressing concerns about the uncertainty of potential risks to human health from bulk APC disposal at strategic locations.