Chapel Hill bisphenol A expert panel consensus statement: integration of mechanisms, effects in animals and potential to impact human health at current levels of exposure.

Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, MA 02111, United States
Reproductive Toxicology (Impact Factor: 2.77). 01/2007; 24(2):131-8. DOI: 10.1016/j.reprotox.2007.07.005
Source: PubMed


Available from: Scott M Belcher, Jun 05, 2015
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    ABSTRACT: While there is evidence that maternal exposure to benzene is associated with spina bifida in offspring, to our knowledge there have been no assessments to evaluate the role of multiple hazardous air pollutants (HAPs) simultaneously on the risk of this relatively common birth defect. In the current study, we evaluated the association between maternal exposure to HAPs identified by the United States Environmental Protection Agency (U.S. EPA) and spina bifida in offspring using hierarchical Bayesian modeling that includes Stochastic Search Variable Selection (SSVS). The Texas Birth Defects Registry provided data on spina bifida cases delivered between 1999 and 2004. The control group was a random sample of unaffected live births, frequency matched to cases on year of birth. Census tract-level estimates of annual HAP levels were obtained from the U.S. EPA's 1999 Assessment System for Population Exposure Nationwide. Using the distribution among controls, exposure was categorized as high exposure (>95(th) percentile), medium exposure (5(th)-95(th) percentile), and low exposure (<5(th) percentile, reference). We used hierarchical Bayesian logistic regression models with SSVS to evaluate the association between HAPs and spina bifida by computing an odds ratio (OR) for each HAP using the posterior mean, and a 95% credible interval (CI) using the 2.5(th) and 97.5(th) quantiles of the posterior samples. Based on previous assessments, any pollutant with a Bayes factor greater than 1 was selected for inclusion in a final model. Twenty-five HAPs were selected in the final analysis to represent "bins" of highly correlated HAPs (ρ > 0.80). We identified two out of 25 HAPs with a Bayes factor greater than 1: quinoline (ORhigh = 2.06, 95% CI: 1.11-3.87, Bayes factor = 1.01) and trichloroethylene (ORmedium = 2.00, 95% CI: 1.14-3.61, Bayes factor = 3.79). Overall there is evidence that quinoline and trichloroethylene may be significant contributors to the risk of spina bifida. Additionally, the use of Bayesian hierarchical models with SSVS is an alternative approach in the evaluation of multiple environmental pollutants on disease risk. This approach can be easily extended to environmental exposures, where novel approaches are needed in the context of multi-pollutant modeling.
    Environmental Health 02/2015; 14(16). DOI:10.1186/1476-069X-14-16 · 2.71 Impact Factor
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    ABSTRACT: Reactive oxygen species (ROS) generation, induced by Bisphenol A (BPA) may cause mammalian sperm damage according to research findings. BPA is a known contaminant that with increased exposure in the body can exert both toxic and estrogenic effects in mammalians cells. The aim of this study was to evaluate the effect of BPA-induced oxidative stress in the liver on epididymal semen quality in adult rat. BPA was mixed in corn oil and intra-peritoneally administered for 20 days in dose dependent manner. After 24 h of the last treatment, rats were weighed, sacrificed and organs harvested for analysis. BPA caused a reduction in the epididymal semen quality and sperm count in a dose dependent manner. Sperm analyses results showed that there was oligozoospermia (˂20 x106 spermatozoids/ml) and asthenozoospermia (motility ˂50%) in the treatment group compared to control groups. The levels malondialdehyde (MDA) and superoxide dismutase (SOD) increased significantly in the treatment group compared to control group (P ˂0.05; P ˂0.01, respectively). While, the levels of glutathione peroxidase (GSH-Px) decreased in the treatment group compared to control group (P ˂0.01). These results indicate that exposure of graded doses of BPA may elicit depletion of antioxidant system and induce oxidative stress in epididymal sperm of rat thereby decreasing sperm count and quality. These findings provide a possible toxicological evidence of an adverse effect of BPA on semen quality.
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    ABSTRACT: Objective. The present study aimed to examine the association between serum BPA and hypertension and evaluated whether it was influenced by estradiol level. Methods. A subsample of 2588 sera randomly selected from the Thai National Health Examination Survey IV, 2009, was measured for serum BPA and estradiol. Logistic regression was used to examine the association controlling for age, sex, diabetes, body mass index, and estradiol level. Results. Compared with the lowest quartile, the adjusted odds ratio (AOR) of hypertension for the fourth quartile of serum BPA was 2.16 (95% CI 1.31, 3.56) in women and 1.44 (0.99, 2.09) in men. There was no interaction between serum BPA and estradiol level. For analysis using log(BPA) as a continuous variable, the AOR per unit change in log(BPA) was 1.09 (95% CI 1.02, 1.16). Among postmenopausal women, the AOR for the fourth quartile of BPA was 2.33 (95% CI 1.31, 4.15) and, for premenopausal women, it was 2.12 (95% CI 0.87, 5.19). Conclusion. Serum BPA was independently associated with hypertension in women and was not likely to be affected by estrogen; however, its mechanism related to blood pressure needs further investigation.
    02/2015; 2015:1-8. DOI:10.1155/2015/594189