3 research outputs found

    Organophosphate esters in indoor dust from 12 countries: Concentrations, composition profiles, and human exposure

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    A total of 20 organophosphate triesters (OPEs), including seven alkyl-OPEs, three chlorinated (Cl)-OPEs, seven aryl-OPEs, and three oligomeric-OPEs were measured in 341 house dust samples collected from 12 countries during the period 2010-2014. OPEs were ubiquitous in indoor dust, and the total concentrations of OPEs (Sigma OPEs; sum of 20 OPEs) ranged from 49.4 to 249,000 ng/g dry weight (dw). Generally, Cl-OPEs were the predominant compounds (51% of total) in indoor dust samples, with a median concentration of 800 ng/g, followed by alkyl-OPEs (31%), aryl-OPEs (17%), and oligomeric-OPEs (1%), with median concentrations of 480, 270, and 21.9 ng/g, respectively. Sigma OPE concentrations in indoor dust from more industrialized countries (South Korea: median, 31,300; Japan: 29,800; and the United States: 26,500 ng/g dw) were one or two orders of magnitude higher than those from less industrialized countries (Greece: 7140, Saudi Arabia: 5310, Kuwait: 4420, Romania: 4110, Vietnam: 1190, China: 1120, Colombia: 374, India: 276, and Pakistan: 138 ng/g dw). Statistically significant positive correlations (0.114 < r < 0.748, p < 0.05) were found among the concentrations of 16 OPEs in dust samples, indicating similar sources of these compounds. The median estimated daily intakes of Sigma OPEs via dust ingestion for children and adults were in the ranges of 0.29-64.8 and 0.07-14.9 ng/kg bw/day, respectively

    Bisphenol A in infant urine and baby-food samples among 9- to 15-month-olds

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    Diet is the predominant source of bisphenol A (BPA) intake, but limited data are available on BPA levels in the diet of younger infants. This study investigated BPA levels in baby-food and urine samples collected from young infants (under 2 years old). Samples of homemade baby food (n = 210) and urine (n = 187) were collected at 9, 12, and 15months after birth from a panel of Korean infants (n = 173). BPA levels in urine and food were measured using HPLC-MS/MS and GC-MS, respectively. BPA was above the limit of detection (LOD) in 85.5-85.7% of the urine samples and 32.5-76.3% of the baby-food samples. The median levels of BPA were 0.45 ng/g wet weight (IQR: not detectable to 5.16 ng/g wet weight) in homemade baby food, 0.93 mu g/L (IQR: <LOD to 2.66 mu g/L) in unadjusted urine samples, and 0.94 mu g/L (IQR: bLOD to 2.80 mu g/L) in urine samples adjusted for specific gravity. The BPA levels detected in this study were comparable or lower compared to previously reported levels of BPA in baby-food and infant urine samples. The BPA concentrations in the baby food of 15-month-old children (median: 5.09 ng/g) were significantly greater than those detected at 9 or 12 months of age (median: bLOD and 0.47 ng/g, respectively). Considering that the dietary changes from solid food with high water content to solid food as infants grew were accompanied by greater exposure to BPA, it is noteworthy that urinary BPA levels did not significantly differ according to infants' age. These results suggest that solid food with high water content did not drive the internal dose in younger infants, implying that there may have been other sources of exposure in their baby-food (other than weaning-food) and the environment, although further study would be needed to confirm this possibility. (C) 2019 Elsevier B.V. All rights reserved.We would like to express our gratitude to the mothers who participated in the Children's Health and Environmental Chemicals in Korea (CHECK) Panel. This study was supported by a grant from the Ministry of Food and Drug Safety (12162MFDS731) in 2012-2013 and National Research Foundation of Korea (BK21 PLUS)

    Major AhR-active chemicals in sediments of Lake Sihwa, South Korea: Application of effect-directed analysis combined with full-scan screening analysis

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    This study utilized effect-directed analysis (EDA) combined with full-scan screening analysis (FSA) to identify aryl hydrocarbon receptor (AhR)-active compounds in sediments of inland creeks flowing into Lake Sihwa, South Korea. The specific objectives were to (i) investigate the major AhR-active fractions of organic extracts of sediments by using H4IIE-luc in vitro bioassay (4 h and 72 h exposures), (ii) quantify known AhR agonists, such as polycyclic aromatic hydrocarbons (PAHs) and styrene oligomers (SOs), (iii) identify unknown AhR agonists by use of gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOFMS), and (iv) determine contributions of AhR agonists to total potencies measured by use of the bioassay. FSA was conducted on fractions F2.6 and F2.7 (aromatics with log K-ow 5-7) in extracts of sediment from Siheung Creek (industrial area). Those fractions exhibited significant AhR-mediated potency as well as relatively great concentrations of PAHs and SOs. FSA detected 461 and 449 compounds in F2.6 and F2.7, respectively. Of these, five tentative candidates of AhR agonist were selected based on NIST library matching, aromatic structures and numbers of rings, and available standards. Benz[b]anthracene, 11H-benzo[a]fluorene, and 4,5-methanochrysene exhibited significant AhR-mediated potency in the H4IIE-luc bioassay, and relative potencies of these compounds were determined. Potency balance analysis demonstrated that these three newly identified AhR agonists explained 1.1% to 67% of total induced AhR-mediated potencies of samples, which were particularly great for industrial sediments. Follow-up studies on sources and ecotoxicological effects of these compounds in coastal environments would be required.The authors appreciate anonymous reviewers for their valuable comments and suggestions and improvements to this article. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIP) (2017R1A4A1015393, 2016R1E1A1A01943004, and 2017R1E1A1A01075067). This work was also supported by the project entitled "Development of techniques for assessment and management of hazardous chemicals in the marine environment (2014-0342)" funded by the Ministry of Oceans and Fisheries of Korea. Prof. Giesy was supported by the Canada Research Chairs program of the Natural Sciences and Engineering of Canada
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