Accumulation and excretion of fenthion, fenthion sulfoxide and fenthion sulfone by killifish (Oryzias latipes)

Abstract

Accumulation and excretion of fenthion and its oxidation products (fenthion sulfoxide and fenthion sulfone) were studied for killifish (Oryzias latipes). The bioconcentration factors (BCF) in the whole body of the fish were 154 at low concentration and 170 at high concentration for fenthion, 1.7 for fenthion sulfoxide and 3.2 for fenthion sulfone. As reference data, partition coefficients between n-octanol and water (K(ow)) were measured for these compounds. LogK(ow) was 4.04 for fenthion, 1.98 for fenthion sulfoxide and 2.02 for fenthion sulfone. Fenthion was partly oxidized to fenthion sulfoxide in the killifish body. The excretion rate constants (k) from the whole body of the fish were 0.20 hr-1 for fenthion, 0.24 hr-1 for fenthion sulfoxide and 0.16 hr-1 for fenthion sulfone. The contamination of fish and other aquatic organisms in the environment by these oxidation products was presumed to be low from the experimental results described above.