6533b831fe1ef96bd1299820

RESEARCH PRODUCT

Chloroanisoles in soils and earthworms

subject

description

One important group of metabolites of chlorophenols in Finnish soils is their methylation products, i.e. chloroanisoles. Bioaccumulation of chloroanisoles into the biomass of earthworms was studied both in laboratory and by taking earthworm samples from contaminated soils. Concentrations of these compounds in the soils were also analysed. In the laboratory experiment, concentrations of 2,3,4,6-tetrachloroanisole (2346-TeCA) and pentachloroanisole (PeCA) were high in earthworms 1 week after introduction (approx. 50 μ/g fat). Later on, the concentrations decreased to a low level at a considerable rate, bcth in soil and in earthworms. The higher the concentration of chloroanisoles in the soil was, the higher was the microbial activity measured as production of carbon dioxide. Demethylation of chloroanisoles back to corresponding chlorophenols was observed. In the field samples taken from an area of a sawmill which had been closed nearly 30 years before, concentrations of TeCA and PeCA in the soil varied from 0.01 to 1 μg/g (dry mass). Chloroanisole concentrations in the tissues of earthworms varied from 0.04 to 0.24 μg/g fat. In Aporrectodea caliginosa tuberculata, which ingest large amounts of soil, higher concentrations were found than in Lumbricus species, which feed on leaf litter from the soil surface.