health hazards posed by chromium-contaminated soils in residential and industrial areas: conclusions of an expert panel

• Published in: Regulatory toxicology and pharmacology Vol. 13; no. 2; pp. 195 - 222
• Main Authors: Paustenbach, D.J, Rinehart, W.E, Sheehan, P.J
• Format: Journal Article
• Language: English
• Published: Netherlands 01.04.1991
• Subjects: Air Pollutants - analysis; chromium; Chromium - toxicity; environmental exposure; Food Contamination - analysis; health hazards; hudson county; Humans; Industry; monitoring; New Jersey; residues; Risk; Soil - analysis; Soil Pollutants - toxicity; soil toxicity; toxicology; Water Supply - analysis; New Jersey
• ISSN: 0273-2300; 1096-0295
• DOI: 10.1016/0273-2300(91)90022-N

Between 1905 and 1971, over 2 million tons of residue from chromite ore processing was generated in Hudson Count, New Jersey of which substantial amounts were used as fill and tank diking. A panel of medical, toxicology, and risk assessment experts was convened in early 1990 to evaluate the potential health hazards posed by the resulting chromium contaminated soil. The Panel concluded that soils containing concentrations of 75 ppm hexavalent chromium [Cr(VI)] and 1000 ppm total chromium compounds (about 95% was trivalent chromium [Cr(III)]) did not pose a significant health hazard to nearby residents and workers. They also determined that exposure to chromium from Hudson County sites posed a negligible cancer hazard to residents. Using risk assessment methods, the Panel estimated that the plausible incremental cancer risk to individuals at residential sites would be substantially less than 1 in 1,000,000. The average measured levels of airborne Cr(VI) at typical industrial sites were more than 1000-fold lower than the current OSHA Permissible Exposure Limit (PEL). The maximum plausible increased cancer risk for an average worker at a dusty industrial site as estimated to be less than 1 in 100.000. The Panel also concluded that chromium-containing crystals, which have occasionally, been found in Hudson County buildings, do not pose a significant hazard. However, they suggested that were the concentration to exceed 5000 ppm Cr(VI) in the crystals, site-specific health risk assessments would be conducted and remediation considered. The Panel evaluated the dermal hazard posed by chromium-contaminated soil and acknowledged that there is a small group of persons approximately 0.1% of the United States population) who currently have a dermal sensitization to Cr(VI) primarily through occupational exposure. Based on published studies of human volunteers, the Panel concluded that a small percentage (less than 5%) of persons already sensitized may respond to Cr(VI) in solution at concentrations above 35 ppm. They decided that a much higher concentration in soil, perhaps 350 ppm Cr(VI), would be necessary to elicit dermatitis because only a fraction of the chromium in soil is soluble. The Panel concluded that it was highly unlikely (if not impossible) for a person to become dermally sensitized to Cr(VI) or Cr(III) at the soil concentrations found in most areas in Hudson County. The Panel was of the opinion that the 75 ppm total chromium [Cr(III) and Cr(VI)] cleanup requirement for Hudson County soils, which was established by the New Jersey Department of Environmental Protection (NJDEP), is unusually stringent and that much higher levels would still be protective of public health. Last, the Panel noted that although biological monitoring can be useful for evaluating persons exposed to relatively high concentrations of CR(VI), the urine or blood sampling of persons living or working near these sites would probably not be beneficial until a more sensitive analytical method is available and/or until a very large control group is evaluated so that the background concentrations of chromium in biological fluids (and the variability) can be defined.