Subchronic Exposure of Mice to Love Canal Soil Contaminants. SILKWORTH, J. B., MCMARTIN, D. N., REJ, R. NARANG, R. S., STEIN, V. B., BRIGGS, R. G., AND KAMINSKY, L. S. (1984). Fundam. Appl. Toxicol. 4, 231–239. The health hazard potential of soil collected from the surface of the Love Canal chemical dump site in Niagara Falls, New York, was assessed in 90-day exposure studies. Female CD-I mice were exposed to two concentrations of the volatile components of 1 kg of soil with and without direct soil contact. Control mice were identically housed but without soil. The soil was replaced weekly and 87 compounds were detected in the air in the cages above fresh and 7-day-old soil as analyzed by gas chromatography/mass spectrometry. The concentration of many of these compounds decreased during the 7-day exposure cycle. Histopathologic, hematologic, and serum enzyme studies followed necropsy of all mice. There was no mortality of mice exposed for up to 90 days under any condition. Thymus and spleen weights relative to body weight were increased after 4 weeks of exposure by inhalation but not after 8 or 12 weeks of exposure, α-, β-, and Δ-Benzenehexachlorides, pentachlorobenzene, and hexachlorobenzene were detected in liver tissue from these animals. Mice exposed to 5- to 10-fold elevated concentrations of volatiles had increased body and relative kidney weights. There was no chemically induced lesion in any animal exposed only to the volatile soil contaminants. Mice exposed by direct contact with the soil without elevated volatile exposure had increased body (10%) and relative liver weights (169%). Centrolobular hepatocyte hypertrophy, which involved 40 to 70% of the lobules, was observed in all mice in this group. Mice exposed to the soil for 90 days by direct contact and simultaneously to elevated volatile concentrations had centrolobular hepatocyte hypertrophy and increased relative liver (184%), spleen (25%), and kidney (14%) weights. These results indicated that Love Canal soil was more toxic by direct contact than without contact, and that the liver was the primary target organ.