Abstract |
Structure-activity analysis was used to evaluate the effects of 19 hazardous organic chemicals on microbial respiration in two slightly acidic soils (a Captina silt loam from Roane County, Tennessee, and a McLaurin sandy loam from Stone County, Mississippi), both low in organic carbon and typical of the southeastern United States. The chemicals included in the study were the following: acrylonitrile, furan, methyl ethyl ketone, tetrahydrofuran, benzene, toluene, 1,2-dichloroethane, p-xylene, chlorobenzene, chloroform, nitrobenzene, trans-1,4-dichloro-2-butene, cis-1,4-dichloro-2-butene, 1,2-dichlorobenzene, 1,2,3-trichloropropane, carbon tetrachloride, 1,2-dibromoethane (ethylene dibromide), 1,2,4,5-tetrachlorobenzene and hexachlorobenzene. Seventeen of the chemicals caused temporary depressions in CO2 efflux in at least one soil, but treatments were not significantly different from controls by the sixth day for most of these compounds, indicating the ability of the microbial community to recover from chemically induced toxicity at this concentration. Acrylonitrile, nitrobenzene, and the 1,4-dichloro-2-butenes caused sustained depressions, whereas methyl ethyl ketone and benzene increased respiration. (Copyright (c) 1989 SETAC.) |