Identification of an accurate soil suspension/dispersion modeling method for use in estimating health-based soil cleanup levels of hexavalent chromium in chromite ore processing residues.
The primary health concern associated with chromite ore processing residues (COPR) at sites in Hudson County, NJ, is the inhalation of Cr(VI) suspended from surface soils. Since health-based soil standards for Cr(VI) will be derived using the inhalation pathway, soil suspension modeling will be necessary to estimate site-specific, health-based soil cleanup levels (HBSCLs). The purpose of this study was to identify the most appropriate particulate emission and air dispersion models for estimating soil suspension at these sites based on their theoretical underpinnings, scientific acceptability, and past performance. The identified modeling approach, the AP-42 particulate emission model and the fugitive dust model (FDM), was used to calculate concentrations of airborne Cr(VI) and TSP at two COPR sites. These estimated concentrations were then compared to concentrations measured at each site. The TSP concentrations calculated using the AP-42/FDM soil suspension modeling approach were all within a factor of 3 of the measured concentrations. The majority of the estimated air concentrations were greater than the measured, indicating that the AP-42/FDM approach tends to overestimate on-site concentrations. The site-specific Cr(VI) HBSCLs for these two sites calculated using this conservative soil suspension modeling approach ranged from 190 to 420 mg/kg.
Scott
P K
PK
ChemRisk Division of McLaren Hart, Wexford, Pennsylvania, USA.
Finley
B L
BL
Sung
H M
HM
Schulze
R H
RH
Turner
D B
DB
D002857:Chromium / Q000032:analysis* / Q000633:toxicity; D006801:Humans; D007220:Industrial Waste / Q000032:analysis*; D008669:Metallurgy; D008962:Models, Theoretical; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity
D007220:Industrial Waste; D012989:Soil Pollutants; D002857:Chromium