| Summary: | 碩士 === 國立臺灣大學 === 環境衛生研究所 === 107 === Perfluoroalkyl substances (PFASs) are widely used in waterproof fabrics and nonstick cookware. Many studies have indicated that PFASs have hepatotoxicity, developmental toxicity, and could disrupt human endocrine systems. Phthalate esters (PAEs), a group of plasticizers, are ubiquitous in the environment and may affect our reproductive organs. Bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) are estrogenic and may pose adverse reproductive effects. Gallium (Ga) and Indium (In) are commonly used in photonic industries; animal studies have shown that these two metals may induce oxidative stress and interfere with cell functions.
This study determined 10 PFASs, six PAEs, three bisphenols, and two metals of Ga and Indium in food samples (pork, pork liver, pork kidney, fish meat, clam, and oyster) and environmental samples (river water and sediment) with three analytical methods that had been developed and validated by Kuan-Ping Chao, Ze-Ying Chen, and You-Chen Liu in 2017. Food samples were collected from three major traditional markets in Hsinchu City; environmental samples were collected from Keya Stream, in which wastewater from Hsinchu Science Park discharges, and Touchien River in Hsinchu. Food samples and environmental samples were collected three times in April, May, and June 2018, respectively. This study analyzed 63 food samples, 21 river water samples, and 19 sediment samples.
Organic analytes were determined with ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). PAEs were separated on an Ascentis Express F5 column (30 × 2.1 mm, 2.0 μm) with mobile phases composed of (B) acetonitrile and (A) 5 mM ammonium acetate(aq) (pH 6.5), and were ionized with positive electrospray ionization (ESI+). The rest organic analytes were separated with a BEH C18 column (50 2.1 mm, 1.7 μm) with mobile phases composed of (B) methanol and (A) 10-mM N-methylmorpholine(aq) (pH 9.6), and were ionized with negative ESI (ESI-). Data were acquired using multiple-reaction monitoring (MRM); the most abundant and the second abundant product ions were selected for quantification and confirmation, respectively.
Food and sediment samples were prepared using QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) approach for organic analysis. Water samples were processed using solid-phase extraction (SPE).
Gallium and Indium were detected using an inductively coupled plasma mass spectrometer (ICP-MS). Food and sediment samples were digested with acids using microwave-assisted digestion for metal analysis.
PFASs were found in foods at low ng/g w.w. levels with higher concentrations in pork liver. Concentrations of individual PAEs could reach g/g w.w.; BBP, DEHP, and DINP were observed in all of the food samples, and were relatively higher in pork liver, pork kidney, and oyster than those in other food items. Bisphenol S and bisphenol F were observed in fish meat and seafood at low ng/g w.w. PFASs, bisphenol S and bisphenol F in river water were found at few ng/L levels, and the concentrations were higher in Keya Stream than those in Touchien River. PAEs in river water were as high as g/L levels, and the concentrations were similar at Keya Stream and Touchien River. PFASs in sediments were found at low ng/g d.w.; PAEs could reach few μg/g d.w.; bisphenol A were observed in sediments at few hundred ng/g d.w. level; bisphenol F and bisphenol S were found at few ng/g d.w. and low ng/g d.w. level, respectively. Trends of concentrations increased from upstream to downstream in all the three categories of analytes in sediment samples with the highest concentration found at the downstream of Keya Stream at Siangya Bridge (K3).
The estimated exposure through food intake was 13.9 ng/kg bw/day to PFASs. The estimated exposure to PAEs was 744 ng/kg bw/day, which DEHP and DINP contributed 33% (244 ng) and 62% (462 ng), respectively. The total exposure to bisphenols were 1.64 ng/kg bw/day. The levels of exposure to PFOA, PFOS, DEHP, BBP, DINP, DIDP and BPA in this study are well within the standards of tolerable daily intake (TDI) set by TFDA. In 2018, EFSA has proposed tolerable weekly intake (TWI) of 13 ng/kg body weight for PFOS and 6 ng/kg body weight for PFOA in foods. Weekly intake of PFOA (8.96 ng/kg bw) in this study showed the need to control PFOA in Taiwan under these new standards.
Ga was in much higher concentrations in clam and oyster (geometric means, GM, at 65.1 and 32.4 ng/g w.w., respectively), and was observed in all other food samples although in much lower levels (GM between 0.18 and 2.02 ng/g w.w.) Levels of Ga in water and sediment reached g/L and mg/kg d.w., respectively, and were about three orders of magnitude than those of In. Concentrations of Indium in the water of Keya Stream after the effluent from Hsinchu Science Park were much higher than the upstream concentrations. This may indicate the impact on water quality from the wastewater of Hsinchu Science Park.
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