A 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES) with the trade name F-53B, is an alternative to perfluorooctanesulfonate (PFOS) in electroplating industry that is uniquely used in China. It was developed as a mist suppressant initially in the 1970s, but the environmental behaviors and potential adverse effects of the 6:2 Cl-PFAES have only recently been investigated. In this work, the occurrence and distribution of perfluoroalkyl sulfonate (PFSA), fluorotelomer sulfonate (FTSA), and PFAES analogues were investigated in municipal sewage sludge samples collected around China. Perfluorobutane, perfluorohexane, perfluorooctane, and perfluorodecanesulfonates, 6:2 and 8:2 FTSAs, and the emerging 6:2 Cl-PFAES were detected. Moreover, 8:2 and 10:2 Cl-PFAESs were identified for the first time as new polyfluorinated contaminants using high resolution mass spectrometry. These fluorinated analytes were further quantified with the aid of commercial and laboratory-purified standards. PFOS was the predominant contaminant with a geometric mean (GM) value of 3.19 ng/g dry weight (d.w.), which was subsequently followed by 6:2 Cl-PFAES and 8:2 Cl-PFAES (GM: 2.15 and 0.50 ng/g d.w., respectively). Both 6:2 and 8:2 Cl-PFAES were positively detected as the major components in the F-53B commercial product, and discrete 6:2 Cl-PFAES/8:2 Cl-PFAES ratios in the product and sludge samples might suggest 8:2 Cl-PFAES had enhanced sorption behavior in the sludge due to the increase in hydrophobicity.

Synthetic phenolic antioxidants (SPAs) are widely used in various industrial and commercial products to retard oxidative reactions and lengthen product shelf life. In recent years, numerous studies have been conducted on the environmental occurrence, human exposure, and toxicity of SPAs. Here, we summarize the current understanding of these issues and provide recommendations for future research directions. SPAs have been detected in various environmental matrices including indoor dust, outdoor air particulates, sea sediment, and river water. Recent studies have also observed the occurrence of SPAs, such as 2,6-ditert-butyl-4-methylphenol (BHT) and 2,4-di-tert-butyl-phenol (DBP), in humans (fat tissues, serum, urine, breast milk, and fingernails). In addition to these parent compounds, some transformation products have also been detected both in the environment and in humans. Human exposure pathways include food intake, dust ingestion, and use of personal care products. For breastfeeding infants, breast milk may be an important exposure pathway. Toxicity studies suggest some SPAs may cause hepatic toxicity, have endocrine disrupting effects, or even be carcinogenic. The toxicity effects of some transformation products are likely worse than those of the parent compound. For example, 2,6-di-tertbutyl-p-benzoquinone (BHT-Q) can cause DNA damage at low concentrations. Future studies should investigate the contamination and environmental behaviors of novel high molecular weight SPAs, toxicity effects of coexposure to several SPAs, and toxicity effects on infants. Future studies should also develop novel SPAs with low toxicity and low migration ability, decreasing the potential for environmental pollution.

Precise determination of organophosphate esters (OPEs) in the environment is crucial to estimating their potential toxicity effects on human health. Previous studies have mainly focused on OPEs from direct sources. This study explored a potential indirect source of OPEs: the oxidation of organophosphite antioxidants (OPAs). OPAs are frequently used to retard degradation in polymers through their oxidation to OPEs. In this work, five OPAs [tris­(2-chloroethyl) phosphite, triphenyl phosphite, tris­(2,4-di-tert-butylphenyl) phosphite, bis­(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, and trisnonylphenol phosphite] could be identified, with geometric mean (GM) concentrations from 2.46 to 70.4 ng/g, in indoor dust. Their oxidation products, triisodecyl phosphate (TiDeP), tris­(2,4-di-tert-butylphenyl) phosphate (AO168O), bis­(2,4-di-tert-butylphenyl) pentaerythritol diphosphate (AO626O2), and trisnonylphenol phosphate (TNPP), were found at significantly higher GM concentrations (30.5–3759 ng/g). Surprisingly, two novel oxidation products AO168O (GM: 3759 ng/g) and TNPP (GM: 2185 ng/g) had higher concentrations than tris­(2-chloroethyl) phosphate (GM: 1608 ng/g) and triphenyl phosphate (GM: 1827 ng/g), which are well-known OPEs. These four novel OPEs (TiDeP, TNPP, AO168O, AO626O2) contributed 54.1% to the total concentration of the eight OPEs. The present investigation demonstrates that oxidation of OPAs is an important indirect source of novel OPEs in indoor environments. This is the first detection of four OPAs and their newly identified OPE oxidation products in indoor dust.

Quaternary ammonium compounds (QACs) have raised considerable attention due to their wide commercial applications and recent discovery of unknown persistent analogues in aqueous environment. In this work, the occurrence and distribution of alkyltrimethylammonium (ATMAC), benzylakyldimethylethylammonium (BAC) and dialkyldimethylammonium (DADMAC) homologues were investigated in fifty-two municipal sewage sludge samples. ATMAC C10−18, BAC C8−18 and paired DADMAC C8:8-C18:18 as well as emerging homologues such as 18:20 were identified for the first time by nontarget qualitative strategies. A triple quadruple mass spectrometer quantification method was also initially verified with the aid of laboratory synthesized standards for the analysis of the mixed DADMACs with no certificated commercial standards currently available. The total concentrations of ATMACs, BACs and DADMACs were in the range of 0.38−293, 0.09−191 and 0.64−344 μg/g dry weight, respectively, and particularly, mixed DADMACs constituted 39 ± 7% of total DADMAC concentrations. The concentrations and profiles of individual homologues further suggested different QAC applications and fate in China. Significant correlations were also found among the concentrations of various QAC homologues as well as wastewater treatment plant (WWTP) characteristics (total organic carbon contents and daily treatment volumes). ■ INTRODUCTIONRapid development of analytical methods and increasing public health concerns have improved the assessment and regulatory strategies for screening chemicals with persistent, bioaccumulative, and toxic potentials, especially from the high production volume chemical (HPVC) list. 1−5 Surfactants are an economically important class of HPVCs, with wide consumer usages and industrial applications. The transport, fate, and possible adverse effects of some important neutral and anion surfactants, such as nonylphenolethoxylates and relevant metabolites, have been extensively investigated in various environmental compartments. 6,7 However, less attention has been raised on cationic surfactants, although some of these could be environmentally persistent as they result from the amphiphilic and electrostatic interactions with negatively charged surfaces and are potentially toxic to aquatic organisms. 8−12 Here, we focused our research on quaternary ammonium compounds (QACs), a class of cationic surfactants that are commonly used as detergents, phase transfer catalysts, fabric softeners, disinfectants as well as preservatives and antielectrostatics in personal care products. 8,13 QACs mainly consist of the alkyltrimethylammonium (ATMACs), benzylalkyldimethylethylammonium (BACs), and dialkyldimethyl-ammonium compounds (DADMACs) as shown in Figure 1. The analysis and ecological risk assessment of QACs in the environment began in the 1980s. QAC residues have been found in surface water, 14 sewage effluent, 15,16 estuarine sediment, 9,13,17−19 sludge, 13,20,21 Received: November 12, 2013