Distribution and mass loads of xenoestrogens bisphenol a, 4-nonylphenol, and 4-tert-octylphenol in rainfall runoff from highly urbanized regions: A comparison with point sources of wastewater

Highlights: • BPA, 4-NP, and 4-t-OP in rainfall runoff, effluents, and river were investigated. • High detection frequencies suggest the ubiquitous in receiving Pearl Rivers. • They were detected in runoff samples, especially high levels in street runoff. • The mass load of rainfall runoff was 3.4–251 times high than WWTP effluents. • Potential high estrogenic activity risks are posed by rainfall runoff. This study pays a special attention to three phenolic endocrine disrupting compounds (EDCs), — bisphenol A (BPA), 4-nonylphenol (4-NP), and 4-tert-octylphenol (4-t-OP) — that are present in urban environments, resultant of several anthropogenic activities that can be also carried through rainfall runoff. We investigated the distributions of BPA, 4-NP, and 4-t-OP in Pearl River basin and estimated the mass loads in rainfall runoff, wastewater treatment plant (WWTP) effluents, and industrial wastewater from urbanized Huizhou and Dongguan regions. These three phenolic EDCs were detected frequently in tributaries and mainstream of Dongjiang River with the maximum 4-NP concentrations of 14,540 ng/L in surface waters and 3088 ng/g in sediments. BPA showed high concentrations in rainfall runoff samples with maximum concentrations of 5873 and 2397 ng/L in Huizhou and Dongguan regions, respectively, while concentrations for 4-NP and 4-t-OP were detected at tens to hundreds of nanograms per liter. Mass loads of phenolic EDCs from rainfall runoff were 3–62 times higher than those of WWTP effluents, suggesting rainfall runoff is an important source of phenolic EDCs into receiving waters. Sources and tributaries showed median to high estrogenic risks, while low to median risks were found in mainstream, implying the source control should be focused.