Toxicity and Uptake Kinetics of Pentachlorophenol on the Eisenia fetida Exposed to Test Soils

Abstract

Pentachlorophenol (PCP) is widely distributed and highly persistent in soil, and represents a threat to the health of ecosystems. The present study aimed to assess the toxicity, bioavailability and uptake kinetics by earthworms on PCP in soils as a function of different aging periods with the attempt to select a good uptake kinetic. The results show that body residues in the controls were significantly different from all the body residues. The bioconcentration factor increased with time at both PCP loadings, the neutral red retention time for earthworms was reduced with increasing exposure concentration of PCP since 28 days of aging, and the NRRT assay was highly sensitive to PCP in E. fetid a lysosomal and appearing decisively more sensitive than the other applied assays, the lysosomal membrane stability may therefore be a useful biomarker tool to estimate toxic effects of PCP on earthworms. The uptake kinetics of PCP in test soil by earthworms could be well described by the uptake kinetics model, with increased aging time, the bioavailability of PCP increased and in theory the rate constants calculated in uptake and elimination studies are indeed constants and can be used to predict accumulation in earthworm. The earthworm uptake PCP demonstrated the enhanced availability of PCP with LMWOA addition, this provides an information to enhance availability of PCP by organic acids.