Occurrence and estrogenic potency of eight bisphenol analogs in sewage sludge from the U.S. EPA targeted national sewage sludge survey

•BPA, BPS and BPF were determined in 76 sewage sludge from the USA.•Bisphenols were found at concentrations ranging from 12.8 to 4730 ng/g dw in sludge.•Only 0.02% of the total BPA production volume was emitted through sludge disposal.•The estrogenic activity of BPA was lower than that of natural estrogens in sludge.

As health concerns over bisphenol A (BPA) in consumer products are mounting, this weak estrogen mimicking compound is gradually being replaced with structural analogs, whose environmental occurrence and estrogen risks are not well understood yet. We used high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) to determine the concentrations of eight bisphenol analogs in 76 sewage sludge samples collected by the U.S. Environmental Protection Agency (EPA) in 2006/2007 from 74 wastewater treatment plants (WWTPs) in 35 states. Bisphenols were detected at the following concentration ranges (ng/g dry weight) and detection frequencies: BPA (6.5–4700; 100%); bisphenol S (BPS; <1.79–1480; 84%); bisphenol F (BPF; <1.79–242; 68%); bisphenol AF (BPAF; <1.79–72.2; 46%); bisphenol P (BPP; <1.79–6.42; <5%), bisphenol B (BPB; <1.79–5.60; <5%), and bisphenol Z (BPZ; <1.79––66.7; <5%). Bisphenol AP (BPAP) was not detected in any of the samples (<1.79 ng/g dw). Concentrations of BPA in sewage sludge were an order of magnitude higher than those reported in China but similar to those in Germany. The calculated 17β-estradiol equivalents (E2EQ) of bisphenols present in sludge samples were 7.74 (0.26–90.5) pg/g dw, which were three orders of magnitude lower than the estrogenic activity contributed by natural estrogens present in the sludge. The calculated mass loading of bisphenols through the disposal of sludge and wastewater was <0.02% of the total U.S. production. As the usage of BPA is expected to decline further, environmental emissions of BPS, BPF, and BPAF are likely to increase in the future. This study establishes baseline levels and estrogenic activity of diverse bisphenol analogs in sewage sludge.