AN ASSESSMENT OF THE TUMORIGENIC PROPERTIES OF A HUDSON COUNTY SOIL SAMPLE HEAVILY CONTAMINATED WITH HEXAVALENT CHROMIUM

During much of this century, Hudson County, New Jersey, was a major ce nter for the processing of chromium ore. Some of the residue from this processing was used in landfills and in construction materials throug hout the county and, in some cases, in highly populated areas. Given t hat it is widely accepted that exposure to hexavalent chromium compoun ds poses a risk for the development of respiratory-tract cancer, conce rns were raised that individuals who worked or resided in chromium-con taminated areas might be at increased risk for the development of resp iratory cancer. To address these concerns, we evaluated a Hudson Count y soil sample--heavily contaminated with chromium ore residue (Cr+6 co ncentration at 5 895 mg/kg)--with respect to its carcinogenic potentia l to the respiratory tract of Sprague-Dawley rats. Groups of animals w ere given repeated intratracheal exposures to one of four materials: ( 1) Hudson County chromium-contaminated soil (CCS), (2) CCS augmented w ith calcium chromate (CaCrO4, (3) CaCr0(4) alone, or (4) control soil. Nominal total doses of Cr+6 for each respective group were 324 mu g/k g 7 975 mu g/kg, 8 700 mu g/kg, and 0.02 mu g/kg. Incidences of malign ant tumors and nephritis were not elevated in any group. Four primary lung tumors appeared in animals that received CCS + CaCrO4, and one pr imary lung tumor appeared in the group treated with CaCrO4 alone. Thes e incidences were not significant statistically, but the rare spontane ous occurrence of these tumors in Sprague-Dawley rats suggested that t hey were treatment related. No primary lung tumors appeared in the con trol or CCS-treated groups.