Bisphenol S and Its Chlorinated Derivatives in Indoor Dust and Human Exposure

Bisphenol S (BPS), an environmental endocrine disruptor, has been identified in global environmental matrices. Nevertheless, limited studies have investigated the presence of chlorinated analogues of BPS (Clx-BPSs) with potential estrogenic activities in environmental matrices. In this study, the occurrence of BPS and five types of Clx-BPSs was characterized in indoor dust (n = 178) from Hangzhou City. BPS was measurable in 94% of indoor dust samples, with an average level of 0.63 μg/g (<LD–2.4 μg/g). Among the detected Clx-BPSs homologues, Cl1-BPS (2-chloro-4-(4-hydroxyphenyl)sulfonylphenol; detection frequency 70%), Cl2-BPS-2 (2-chloro-4-(3-chloro-4-hydroxyphenyl)sulfonylphenol; 65%), and Cl2-BPS-1 (2,6-dichloro-4-(4-hydroxyphenyl)sulfonylphenol; 61%) were among the frequently detected Clx-BPSs. Cl1-BPS was the most abundant analyte, with an average of 0.048 μg/g (<LD—0.24 μg/g), followed by Cl2-BPS-1 (0.035 μg/g, <LD—0.14 μg/g), and Cl2-BPS-2 (0.031 μg/g, <LD—0.13 μg/g). Significant correlations in indoor dust concentrations were observed between BPS and Cl1-BPS (p < 0.01), as well as between BPS and Cl2-BPS-1 (p < 0.01). Moreover, an estimation was made for the total daily intake of Clx-BPSs via the ingestion of indoor dust by infants, children, and adults. This study presents the first evidence of the existence of Clx-BPSs in indoor dust, concurrently highlighting the necessity to address their potential human exposure risks.