Hexing Wang

Association between bisphenol A exposure and body mass index in Chinese school children: a cross-sectional study

BackgroundThere is increasing evidence suggesting that Bisphenol A (BPA), one of the highest volume chemicals produced worldwide, can interfere with the body’s natural weight control mechanisms to promote obesity. However, epidemiological studies for this are limited, especially for children.MethodsA cross-sectional study was conducted to investigate the association between BPA exposure and body mass index (BMI) in school children. Three primary and three middle schools were randomly selected from 26 primary and 30 middle candidate schools in Changning District of Shanghai City in China. According to the BMI-based criteria by age and sex for screening of overweight or obese children, we randomly chose 20 obese, 10 overweight, and 30 normal weight children aged 8-15 years of age from each selected school. First morning urine was collected and total urine BPA concentrations were determined by ultra-performance liquid chromatography tandem mass spectrometry. Multiple linear regression analysis was conducted to examine the association of urine BPA concentrations and daily intake estimates with BMI.ResultsBPA was detected in 84.9% of urine samples with a geometric mean of 0.45 ng/mL. The daily intake estimates ranged from 0.03 μg/day to 1.96 μg/day with a geometric mean of 0.37 μg/day. The average urine BPA concentrations and daily intake estimates were similar for boys and girls, but significantly higher in older children than younger ones, and showed an increasing trend with BMI. Multiple linear regression analyses showed that urine BPA concentrations were significantly associated with increasing BMI values in all subjects after adjustment for age and sex and the results were similar before and after corrected by urine specific gravity. When stratified by age or sex, the associations remained significant in females and in those 8-11 years of age before corrected by specific gravity. Similar results were shown for the association between BMI and daily intake estimates.ConclusionsThere is a possibility that BPA exposure increases BMI in school children. Given the cross-sectional nature of this study, longitudinal studies are warranted to confirm BPA exposure as a contributor to increased BMI in children.

Urinary phthalate metabolites are associated with body mass index and waist circumference in Chinese school children.

Background Lab studies have suggested that ubiquitous phthalate exposures are related to obesity, but relevant epidemiological studies are scarce, especially for children. Objective To investigate the association of phthalate exposures with body mass index (BMI) and waist circumference (WC) in Chinese school children. Methods A cross-sectional study was conducted in three primary and three middle schools randomly selected from Changning District of Shanghai City of China in 2011–2012. According to the physical examination data in October, 2011, 124 normal weight, 53 overweight, and 82 obese students 8–15 years of age were randomly chosen from these schools on the basis of BMI-based age- and sex-specific criterion. First morning urine was collected in January, 2012, and fourteen urine phthalate metabolites (free plus conjugated) were determined by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Multiple linear regression was used to explore the associations between naturally log-transformed urine phthalate metabolites and BMI or WC. Results The urine specific gravity-corrected concentrations of nine urine phthalate metabolites and five molar sums were positively associated with BMI or WC in Chinese school children after adjustment for age and sex. However, when other urine phthalate metabolites were included in the models together with age and sex as covariables, most of these significant associations disappeared except for mono (2-ethylhexyl) phthalate (MEHP) and monoethyl phthalate (MEP). Additionally, some associations showed sex- or age-specific differences. Conclusions Some phthalate exposures were associated with BMI or WC in Chinese school children. Given the cross-sectional nature of this study and lack of some important obesity-related covariables, further studies are needed to confirm the associations.

Antibiotics in Drinking Water in Shanghai and Their Contribution to Antibiotic Exposure of School Children

A variety of antibiotics have been found in aquatic environments, but antibiotics in drinking water and their contribution to antibiotic exposure in human are not well-explored. For this, representative drinking water samples and 530 urine samples from schoolchildren were selected in Shanghai, and 21 common antibiotics (five macrolides, two β-lactams, three tetracyclines, four fluoquinolones, four sulfonamides, and three phenicols) were measured in water samples and urines by isotope dilution two-dimensional ultraperformance liquid chromatography coupled with high-resolution quadrupole time-of-flight mass spectrometry. Drinking water included 46 terminal tap water samples from different spots in the distribution system of the city, 45 bottled water samples from 14 common brands, and eight barreled water samples of different brands. Of 21 antibiotics, only florfenicol and thiamphenicol were found in tap water, with the median concentrations of 0.0089 ng/mL and 0.0064 ng/mL, respectively; only florfenicol was found in three bottled water samples from a same brand, with the concentrations ranging from 0.00060 to 0.0010 ng/mL; no antibiotics were found in barreled water. In contrast, besides florfenicol and thiamphenicol, an additional 17 antibiotics were detected in urine samples, and the total daily exposure doses and detection frequencies of florfenicol and thiamphenicol based on urine samples were significantly and substantially higher than their predicted daily exposure doses and detection frequencies from drinking water by Monte Carlo Simulation. These data indicated that drinking water was contaminated by some antibiotics in Shanghai, but played a limited role in antibiotic exposure of children.

Antibiotic body burden of Chinese school children: a multisite biomonitoring-based study.

To explore the antibiotic body burden of Chinese school children, total urinary concentrations (free and conjugated) of 18 representative antibiotics (5 macrolides, 2 β-lactams, 3 tetracyclines, 4 quinolones, and 4 sulfonamides) were measured by ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry among 1064 school students recruited from 3 economically and geographically distinct areas in east China in 2013. All 18 antibiotics were detected in urine samples with the detection frequencies ranging from 0.4 to 19.6%. The antibiotics were detected in 58.3% of urine samples overall, and this detection frequency reached at 74.4% in one study site. Of them, 47.8% of the urine samples had a sum of mass concentration of all antibiotics between 0.1 (minimum) and 20.0 ng/mL, and 8 antibiotics had their concentrations of above 1000 ng/mL in some urine samples. Three veterinary antibiotics, 4 human antibiotics, and 11 human/veterinary antibiotics were found overall in 6.3, 19.9, and 49.4% of urine samples, respectively. The detection frequencies and concentration levels of antibiotics in urine samples differed by study areas. Concerning mixed exposures, a total of 137 combinations of antibiotics and 20 combinations of antibiotic categories were found overall. Two or more antibiotics or categories were concurrently detected in more than 20% of urine samples. On the basis of a usage analysis, contaminated food or environment might be relevant exposure sources for tetracyclines, quinolones, and sulfonamides.

Antibiotics detected in urines and adipogenesis in school children

BACKGROUND Although antibiotic use during early life has been demonstrated to be related to the altered adipogenesis in later life, limited data are available for the effect of antibiotic exposure in school children on adiposity from various sources, including from the use or contaminated food or drinking water. OBJECTIVE To explore the association between the internal exposure of antibiotics from various sources and adipogenesis in school children using the biomonitoring of urinary antibiotics. METHODS After 586 school children aged 8-11years were selected from Shanghai in 2013, total urinary concentrations (free and conjugated) of 21 common antibiotics from six categories (macrolides, β-lactams, tetracyclines, fluoroquinolones, sulfonamides, and phenicols), including five human antibiotics (HAs), two antibiotics preferred as HA, four veterinary antibiotics (VAs), and ten antibiotics preferred as VA, were measured by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Creatinine-corrected urinary concentrations of antibiotics were used to assess their exposure. Overweight or obesity was determined by the body mass index or waist circumference-based criteria deriving from national data. RESULTS All 21 antibiotics were found in urines with the overall detection frequency of 79.6%. The multinomial logistic regression analyses showed the significant associations of overweight and obesity with the exposure to VAs and antibiotics preferred as VA, but not with HAs or antibiotics preferred as HA. After adjusted for a number of obesity-relevant variables, the odds ratios (95% confidence interval) of BMI-based obesity risk of tertiles 2 and 3 of urinary concentrations relative to tertile 1 were respectively 2.54 (1.27, 5.07) and 2.92 (1.45, 5.87) for florfenicol, 0.57 (0.12, 2.63) and 3.63 (1.41, 9.32) for trimethoprim, and 3.00 (1.56, 5.76) and 1.99 (0.99, 4.01) for sum of veterinary antibiotics. Similar results were found when the outcome used WC-based obesity risk. The associations were sex related and mainly observed in boys. CONCLUSIONS Some types of antibiotic exposure, which were mainly from food or drinking water, were associated with an increased risk of obesity in school children. Due to the cross-sectional design, more longitudinal and experimental studies are warranted to further test these findings.

Exposure to bisphenol A among school children in eastern China: A multicenter cross-sectional study

Bisphenol A (BPA) is one of the highest production and consumption volume chemicals in the world. Although exposure of children to BPA has been studied in Western countries, little is known about its level in China. In this study, total BPA was measured in the morning urine samples of 666 school children aged 9–12 years from three regions in eastern China in 2012. A rapid and sensitive ultraperformance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) method was used for the measurement and urinary concentrations of BPA were presented as unadjusted (ng/ml), creatinine-adjusted (μg/g creatinine) and specific gravity (SG)-adjusted (ng/ml) forms. BPA was detected in 98.9% of urine samples with their unadjusted concentrations ranging from 0.1 to 326.0 ng/ml (LOD=0.06 ng/ml), indicating that the exposure of BPA was common for school children living in eastern China. The geometric mean and median of BPA was 1.11 ng/ml (creatinine-adjusted: 2.32 μg/g creatinine; SG-adjusted: 1.17 ng/ml) and 1.00 ng/ml (creatinine-adjusted: 2.22 μg/g creatinine; SG-adjusted: 1.07 ng/ml), respectively. The highest urinary BPA level was found in the age group of 12 years with GM concentration of 1.55 ng/ml, and it decreased with decreasing age (11 years: 1.18 ng/ml; 10 years: 1.05 ng/ml; and 9 years: 0.99 ng/ml), but there was a lack of consistency for age associated with BPA levels in three study areas. The estimated daily intake of BPA (0.023 μg/kg bw/day) was much lower than the tolerable daily and reference dose of 50 μg/kg bw/day recommended by either the European Food Safety Authority or the US Environment Protection Agency. There was no significant difference in urinary BPA concentrations between children who were overweight or obese and those with normal weight (P=0.26), whereas BPA daily intake was unexpectedly higher among normal-weight children (P=0.003). Compared with creatinine correction, the correction method of specific gravity is preferred to evaluate BPA exposure for children.

Influence of Bisphenol A on Thyroid Volume and Structure Independent of Iodine in School Children.

Background Although several studies have evaluated the relationship between bisphenol A (BPA) and thyroid functions, their results are not entirely consistent. Little is known about BPA in relation to thyroid volume and structure. Methods We examined the association of BPA with thyroid volume and thyroid nodules using data from 718 Chinese children living in the East Coast of China in 2012. First morning urine samples were collected for the determination of urinary BPA, creatinine, and urinary iodine concentrations (UIC). Thyroid volume (TV) and nodules were assessed by thyroid ultrasonography. Results The median of TV was 3.14ml. 459(63.9%) children took iodized salt at home and the median of UIC was 159μg/l. BPA was detected in 99.9% of the urine samples and the medians for boys and girls were 2.64 and 2.35μg/g creatinine, respectively. Of all participants 14.0% had thyroid nodules. Urinary BPA concentration was inversely associated with thyroid volume (β = -0.033, 95% CI: -0.053, -0.013) and the risk for multiple nodules (OR = 0.78; 95% CI: 0.63, 0.97). The associations above were similar for children who consumed iodized salt and those consumed non-iodized salt. Conclusions The data suggest that BPA may be one of the influencing factors for TV and thyroid nodules and its effects are independent of iodine nutrition status in children.

Simultaneous Analysis of Nine Estrogens in Milk Powder with Ultra-Performance Liquid Chromatography Coupled to Quadrupole Time-of-Flight Mass Spectrometry

Abstract A rapid, sensitive, and specific method has been developed and validated for the simultaneous analysis of nine estrogens in milk powder, including estriol, β-estradiol, a-estradiol, equilin, 17a-ethinylestradiol, estrone, diethylstilbestrol, dienestrol, and hexestrol using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The milk powder was dissolved in water, the estrogens were extracted with acetonitrile using ultrasonication, and the fat in the extracted solution was removed by liquid-liquid extraction with n-hexane. Then, the estrogens were purified using a NH2-containing solid-phase extraction cartridge, separated on a Waters ACQUITY UPLC HSS T3 column (100 mm × 2.1 mm × 1.8 μm), and analyzed both qualitatively and quantitatively by UPLC-Q-TOF-MS. The overall analysis time of the proposed method was 13 minutes, and the linear range was between 0.001–0.5 mg L−1, with a correlation coefficient greater than 0.993. The limits of detection for the compounds were 0.11–0.30 μg kg−1, and the limits of quantification were within the range 0.37–1.0 μg kg−1. The mass errors between the theoretical and experimental masses obtained for the deprotonated molecules of the nine estrogens and the internal standard (β-estradiol-d3) were between −1.0 and 0.9 mDa. At the spiked levels of 1, 2, 10, and 100 μg kg−1, the average recoveries ranged from 61% to 137%, with relative standard deviations ranging between 1.0% and 22.6%, as determined by the matrix-matched internal-standard method. The results showed that the proposed method was suitable for the multiresidue detection of estrogens in milk powder and was successfully applied to the detection of estrogens in seven real milk powder samples.

Environmental and food contamination with plasticisers in China

e4 www.thelancet.com Vol 378 November 5, 2011 3 Flora SJ, Pachauri V. Chelation in metal intoxication. Int J Environ Res Public Health 2010; 7: 2745–88. 4 Bradberry S, Vale A. Dimercaptosuccinic acid (succimer; DMSA) in inorganic lead poisoning. Clin Toxicol 2009; 47: 617–31. 5 Anon. Investigation into blood lead poisoning case in Jiahe, Hunan. Xinhua News March 16, 2010. http://news.xinhuanet.com/ politics/2010-03/16/content_13178998_6. htm (accessed June 14, 2011). can be exposed to toxic plasticisers through ingestion, inhalation, and dermal exposure. DEHP, the most commonly used and produced phthalate, has been widely detected in the environment including water, air, soil, and food products in China (table). The latest (unpublished) data from our laboratory show an average concentration of DEHP of 0·472 μg/L and a concentration of dibutyl phthalate (DBP) of 0·563 μg/L in drinking water in Shanghai. Other studies indicate that the estimated daily intakes of DEHP and DBP for Chinese people exceeded the reference dose of the US Environmental Protection Agency and the tolerable daily intake of the European Food Safety Authority. In view of the environmental ubiquity of plasticisers in China, short-term and long-term eff ects of environmental exposure to toxic plasticisers on population health should be regarded as a research priority to provide urgently needed information for proper interventions.

Urinary Antibiotics of Pregnant Women in Eastern China and Cumulative Health Risk Assessment

Exposure to antibiotics during pregnancy can pose a systematic effect on human health. A few biomonitoring studies have demonstrated an extensive exposure of children to antibiotics, but there is still a lack of data for pregnant women. To assess the exposure of pregnant women to antibiotics and potential health risk, we investigated 536 pregnant women aged 16-42 years from two geographically different study sites in Eastern China in 2015. We measured 21 antibiotics of five categories (seven fluoroquinolones, three phenicols, four tetracyclines, three macrolides, and four sulfonamides) in urine using the isotope dilution ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. The hazard index (HI) was calculated on the basis of estimated daily exposure dose and acceptable daily intakes. A total of 16 antibiotics were found in urine, with detection frequencies between 0.2 and 16.0%. Antibiotics were overall detected in 41.6% of urine, and two or more antibiotics were detected in 13.1% of urine. Ciprofloxacin, ofloxacin, and trimethoprim were most frequently detected in urine, with detection frequencies between 10 and 20%. The majority of the antibiotics tested had an estimated daily exposure dose less than 1 μg/kg/day, and 4.3% of pregnant women had a HI value of more than 1. These findings indicated that pregnant women were frequently exposed to antibiotics and some individuals were in the potential risk of adverse microbiological effects induced by antibiotics.