Fate of Parabens and Their Metabolites in Two Wastewater Treatment Plants in New York State, United States

Little is known about the occurrence and fate of parabens and their metabolites in wastewater treatment plants (WWTPs). In this study, mass loadings, removal efficiencies, and environmental emission of six parabens, four of their metabolites (4-hydroxy benzoate, 3,4-dihydroxy benzoate, methyl-protocatechuate, and ethyl-protocatechuate) and benzoic acid were studied based on the concentrations determined in wastewater influent, primary effluent, final effluent, suspended particulate matter (SPM), and sludge collected from two WWTPs (denoted as WWTPA and WWTPB) in the Albany area of New York State. The median respective concentrations of sum of parabens (Sigma parabens = 6 parent compounds) and paraben-metabolites (Sigma metabolites = 4 metabolites) were 73.1-158 and 5460-10,000 ng/L in influents, and 1.96-5.57 and 2060-2550 ng/L in final effluents. The concentrations of Sigma metabolites were significantly higher than those of Sigma parabens in sludge and SPM. The removal efficiencies for parabens (89.6-99.9%) were higher than those for their metabolites (25.9-90.6%). The respective mass loadings of parabens and their metabolites were 46.3 and 6210 mg/d/1000 people for WWTPA and 176 and 63,100 mg/d/1000 people for WWTPB. The environmental emission of parabens and their metabolites through WWTP discharges was 4.85-6.16 and 1270-2050 mg/d/1000 people, respectively.