DEVELOPMENT OF QSARS IN TERRESTRIAL ECOTOXICOLOGY - EARTHWORM TOXICITY AND SOIL SORPTION OF CHLOROPHENOLS, CHLOROBENZENES AND DICHLOROANILINE

Soil adsorption and the toxicity towards earthworms of four chlorobenzenes were investigated in two soil types. The toxicity tests were carried out with two earthworm species, i.e. Eisenia andrei and Lumbricus rubellus. LC50 values in mg/kg dry soil were recalculated as molar concentrations in pore water using data from soil adsorption experiments. Attempts have been made to develop QSARs using these results and including data on five chlorophenols, dichloroaniline and trichlorobenzene in four soils published previously. Significant QSAR relationships were obtained between (i) adsorption coefficients (log K(om)) and the octanol/water partition coefficient (log P(oct)), and (ii) LC50 values (in mu-mol/l soil pore water) and log P(oct). A significant increase of the quality of the QSAR relationships was obtained after correcting the data on chlorophenols for dissociation effects of soil pH by recalculating K(om) or LC50 (in mu-mol/l soil pore water) values to concentrations of non-dissociated fractions.