Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil. 3. Sublethal effects on soil invertebrates

Sewage sludge applied to agricultural soils often contains considerable amo unts of linear alkylbenzene sulfonates (LAS). Toxic effects of LAS on soil organisms should, therefore, be evaluated to ensure safe use of sewage slud ge as a fertilizer In this study, dose-response relationships for the toxic ity of Na-LAS to six species of soil invertebrates (survival, reproduction, and growth) were established using a sandy, agricultural soil as test subs trate. In general, toxic effects on reproduction and growth appeared when t he concentration in soil exceeded 40 to 60 mg/kg. Reproduction was approxim ately fourfold more sensitive in earthworms and enchytraeids than in spring tails and mites. It is argued that this difference in sensitivity is relate d to the dependency of soil pore water, which is high in the annelids but c omparatively low in the arthropods.