| We investigated effects of storage temperature and duration on release of antimony (Sb), bisphenol A (BPA) and phathlates (PAEs) from 16 brands of polyethylene terephthalate (PET) drinking water bottles in China. The PAEs studied include dimethyl phthalate (DMP), di-n-butyl phthalate (DBP),benzyl butyl phthalate (BBP) and di-2-ethylhexyl phthalate (DEHP). Before the release experiment, we also measured the total contents of Sb in all PET bottles by acid-digestion on hot-plate at 250℃ for 4 hrs, and extracted BPA and PAEs by ultrasonic-extraction using ethanol as solvent for 2 days. The values for Sb were 104-166 mg/kg; BPA were 37.7-64.1μg/kg; and the DMP, DBP, BBP, and DEHP were 40.6-57.4,5.14-7.08,14.1-19.0 and 1.85-3.62μg/kg, respectively. Meanwhile, the initial concentrations of Sb, BPA and PAEs in PET bottled water, were 55.1-597 and 1.38-48.6 ng/L, and only sample 6 and 9 have detectable PAEs, i.e., BBP (35.4±28.3 and 38.4±0.00 ng/L), DEHP (69.1±0.00 and 883±70.0 ng/L) and DBP (0 and 191±64.8 ng/L). Milli-Q water was used as the aqueous stimulant in the migration test. After 1-wk storage, Sb migrated from the 16 PET bottles increased from 1.88-8.32 ng/L at 4℃, to 2.10-18.4 ng/L at 25℃ and to 20.3-2604 ng/L at 70℃. The corresponding migration for BPA were relatively less with values of 0.26-18.7,0.62-22.6, and 2.89-38.9 ng/L. However, for PAEs, no DMP, DEP, and BBP were detectable.In the case of brand 7, these values were 18.5±1.52, 77.1±3.68, and 53.3±3.48 ng/L for DBP; and 5.78±0.18,12.9±0.02, and 10.7±0.16 ng/L for DEHP, indicating that no effect of temperature can be observed on PAE migration, even at 70℃. As for the influence of storage duration on contaminant migration, Sb increased with storage duration up to 44-wk, and the migration rates decreased with storage time, indicating that Sb migrated from PET bottles may become stable under long term storage. The Sb migration amount after 44 weeks at 70℃ was 197-9211 ng/L, with the highest value of 9211 ng/L for brand 10, which was higher than the maximum concentration limit (MCL) based on EPA regulation for water. Since the summer heat and the common storage duration of one case of PET bottled water, we evaluated the human health risk based on the storage at 70℃ for 4-wk, Sb release in one brand exceeded the USEPA regulated chemical daily intake (CDI,400 ng/kg·bw/d) with values of 409 and 1430 ng/kg·bw/d for adult and children. We also measured the Sb speciation that released from PET bottle into Milli-Q water, found only less toxic Sb(V) was exist. Migration amount of BPA after 44weeks at 70℃ were lower with values of 443-1161 ng/L, which was well below the EPA MCL (10μg/L). Due to the high background contamination, there is sudden increase trend for PAEs during the 44-week storage. The non-migration behavior indicated that PAEs measured in the current study may come from the unavoidable background blank not from PET bottles. Therefore, the domestic PET bottled water are generally safe for drink only if proper storage condition was applied. Besides, we also analyzed the effects of PET bottle characteristics (thickness, weight, density and inner area) on contaminant migration, and found that only thickness and weight have positive correlations with Sb and BPA concentrations of the initial PET bottled water. Due to the fact that complexity influence of many factors (temperature, storage duration, PET bottle characteristics and chemical properties of PET bottled drinks) and low pH can stimulate chemical release from PET bottle into drinks, pH can also affect Sb speciation in PET bottled water, more attention should be paid on drinks, especially the acid soda drinks in PET bottles in the future study.We also investigated the safety of children toys in China. Totally 48 toys, including plastic, metallic, play dough, and jigsaw puzzle, were purchased from Nanjing markets. The total lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd), antimony (Sb), and nickel (Ni) in all the samples were measured after acid-digestion on hot-plate at 250℃ for 4 hrs. Ten of the 48 tested samples had excessive amount of metals higher the European regulation. For sample 39-42 (metallic toys), the Pb concentrations were (6.03±2.04)×103, (4.96±0.07)×103, (8.57±0.30)×105, and (1.91±0.75)×105 mg/kg, respectively; the Cr concentrations of sample 9-12 were 846±11.5, 753±79.9,1292±321, and 3212±120 mg/kg; the concentrations of Ni in sample 39,43, and 44 were 1947±158,1169±104, and 1306±82.6 mg/kg, respectively; and for sample 39 and 41, they also have high concentrations of Cd, which were 139±3.06 and 42.1±1.33 mg/kg.In order to study the bioaccessibility of metals in toy samples, artificial saliva,0.07 M HCl, and 0.43 M HNO3 were used to extract metals in these 10 samples and other 12 samples. Varies results were got for the three surrogates (saliva, HCl, and HNO3), indicating diluted acid can’t be simply used as stimulant for risk assessment due to the higher results than saliva extraction. For sample 40 and 42, although high Pb concentrations ((4.96±0.07)×103 and(1.91±0.75)×105 mg/kg) were found in the two samples, no Pb was extractable by saliva. The metals dissolved in saliva of 16 in 22 samples pose serious health risk on children between 6 months and 1 years old. Besides, more attention should be put on Cr speciation of children toys in the near future since high Cr concentrations were detected in some sample (9-12 and 46-50), and Cr(Ⅵ) is more toxic than Cr(Ⅲ). |
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