Persistence of estrogenic activity in soils following land application of biosolids.

Estrogenic compounds may enter the environment when biosolids are applied to land. In the present study, soil samples were collected over 4 mo from a field trial following addition of biosolids. The recombinant yeast estrogen screen bioassay identified estrogenic activity in the soil at all sampling times to concentrations up to 2.3 µg 17ß-estradiol equivalency/kg. The present results indicate the potential for estrogenic compounds to persist in soil following biosolids application.