Occurrence of eight bisphenol analogues in indoor dust from the United States and several Asian countries: implications for human exposure.

Bisphenol A has been reported to be a ubiquitous contaminant in indoor dust, and human exposure to this compound is well documented. Information on the occurrence of and human exposure to other bisphenol analogues is limited. In this study, eight bisphenol analogues, namely 2,2-bis(4-hydroxyphenyl)propane (BPA), 4,4'-(hexafluoroisopropylidene)diphenol (BPAF), 4,4'-(1-phenylethylidene)bisphenol (BPAP), 2,2-bis(4-hydroxyphenyl)butane (BPB), 4,4'-dihydroxydiphenylmethane (BPF), 4,4'-(1,4-phenylenediisopropylidene)bisphenol (BPP), 4,4'- sulfonyldiphenol (BPS), and 4,4'-cyclohexylidenebisphenol (BPZ), were determined in indoor dust samples (n = 156) collected from the United States (U.S.), China, Japan, and Korea. Samples were extracted by solid-liquid extraction, purified by automated solid phase extraction methods, and determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total concentrations of bisphenols (∑BPs; sum of eight bisphenols) in dust were in the range of 0.026-111 μg/g (geometric mean: 2.29 μg/g). BPA, BPS, and BPF were the three major bisphenols, accounting for >98% of the total concentrations. Other bisphenol analogues were rare or not detected, with the exception of BPAF, which was found in 76% of the 41 samples collected in Korea (geometric mean: 0.0039 μg/g). The indoor dust samples from Korea contained the highest concentrations of both individual and total bisphenols. BPA concentrations in dust were compared among three microenvironments (house, office, and laboratory). The estimated median daily intake (EDI) of ∑BPs through dust ingestion in the U.S., China, Japan, and Korea was 12.6, 4.61, 15.8, and 18.6 ng/kg body weight (bw)/day, respectively, for toddlers and 1.72, 0.78, 2.65, and 3.13 ng/kg bw/day, respectively, for adults. This is the first report on the occurrence of bisphenols, other than BPA, in indoor dust.