Airborne Concentrations of Trivalent and Hexavalent Chromium from Contaminated Soils at Unpaved and Partially Paved Commercial/Industrial Sites

Abstract

The primary health hazard to people in areas surrounding contaminated sites is often believed to be exposure to airborne contaminants. Due to insensitive sampling or analytical methods for many chemicals, including hexavalent chromium [Cr(VI)], the only option available for quantifying the hazard posed by ambient airborne concentrations of these chemicals has been limited to predictions based on various modeling approaches. Due to the use of compounded worst-case input parameters in the models, the resulting predictions have often been of questionable accuracy and relevancy. A recent advance in the sampling and analytical methods for airborne Cr(VI) has enabled direct measurement of the low concentrations typically found in ambient air. This method was used to quantify airborne Cr(VI) levels at both indoor and outdoor locations at 21 sites in Hudson County, New Jersey which have soils containing chromite ore processing residue. Of the 21 sites evaluated, nine were unpaved or partially paved industrial/ commercial sites or roadways with a moderate to high level of heavy truck traffic. Most of the remainder were commercial facilities with partially paved or unpaved parking lots and only light vehicle traffic. In addition, 15 residential sites in the area which do not have contaminated soil were sampled to characterize background levels of Cr(VI). The overall arithmetic mean values for indoor and outdoor Cr(VI) in total suspended particulates at the 21 industrial sites were 3.0 ng/m 3 and 9.9 ng/m 3 , respectively. The indoor Cr(VI) concentrations measured at the 15 residential sites ranged from 0.38 to 3.3 ng/m 3 .Airborne Cr(VI) levels outdoors at sites with chromite ore residue appear to be primarily influenced by the level of local vehicle traffic. Measured outdoor concentrations at sites with light vehicle traffic were generally low, within the range of levels measured indoors at the residential sites, and not strongly influenced by Cr(VI) concentrations in surface soils. At sites with a high rate of vehicle traffic, outdoor Cr(VI) concentrations exceeded background levels only on days when surface soils were dry. The average concentrations measured at these sites were more than 5,000-times lower than the current occupational exposure limit for Cr(VI) (TLV = 0.05 mg/m 3 ); thus it may be concluded that these low concentrations of Cr(VI) do not present a significant health hazard to on-site or nearby workers.

Airborne Hexavalent Chromium in Southwestern Ontario

“…Based on the work by Sheehan et al, 4 the anticipated airborne concentrations of Cr(vi) in the Windsor airshed were then expected to be 1-5 ηg/m 3 for both the outdoor and indoor environments. These figures would also be in agreement with the published work of Falerios et al 8 who found that background levels of Cr(vi) of perhaps 1-4 ηg/m 3 exist in urban air as a result of a variety of anthropogenic sources. The MOEE first implemented the new Cr(vi) methodologies during this study.…”

Soil ingestion rate determination in a rural population of Alberta, Canada practicing a wilderness lifestyle

“…The aboriginal people of the Cold Lake First Nations belong to the Dene Suline tribe, whose traditional lands ranged from south of Bonnyville, Alberta to the northernmost point at Peter Pond Lake, Saskatchewan. The area has a humid continental climate, with a lower than average rainfall compared to other Canadian cities, and contains many unpaved roads that can contribute to airborne dust particles (Falerios et al, 1992;Gómez et al, 2005;James et al, 2012). Local bedrock geology is predominantly marine shale of the Lea Park Formation from the Upper Cretaceous (Prior et al, 2013) overlain by various fluvial sediments and glacio-fluvial tills (Fenton and Andriashek, 1983).…”

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

“…This industrial site sampling program has been described in detail elsewhere. 2,4 These samples were collected and analyzed using the ASTM Standard Test Method D 5281-92 for the collection of airborne Cr(VI) and the EPA SW-846 Method 6010 for the collection of total chromium and TSP. 27 The main purpose of this sampling effort was to characterize the ambient air concentrations of Cr(VI) and total chromium at each site.…”

“…In order to quantitatively address the potential inhalation hazards posed by this material, hundreds of air samples were collected and analyzed for Cr(VI) at these sites using a sensitive new method, American Society of Testing and Materials (ASTM) Standard Test Method D 5281-92, developed specifically for this purpose. [2][3][4] Additionally, concentrations of Cr(VI) in surface soil were characterized at these sites in…”