High-performance liquid chromatography-bioassay profiles of endocrine disrupters discharged from point and non-point pollution sources in Lake Biwa basin

Toxic pollution loading from both point and non‐point sources in Lake Biwa should be further reduced. In order to tackle toxicity problems, it is necessary to analyse characteristics of toxic pollution. We have developed a new profiling technique to display toxic distributions of endocrine disrupters in complex mixtures of environmental samples, using high‐performance liquid chromatography in combination with yeast bioassays. We have applied this technique to the major point and non‐point pollution sources in the Lake Biwa basin, that is, to municipal sewage‐treatment water (point) and road dust (non‐point). The dominant oestrogenic chemical in sewage‐treatment water was 17 β‐estradiol. The extracts from screened road dust showed arylhydrocarbon‐receptor binding activity (AhR–ligand activity), with much of this located in smaller particles of sifted dust. There were at least seven major AhR–ligand peaks in the road‐dust sample.