Effects of in utero exposure to Bisphenol A or diethylstilbestrol on the adult male reproductive system

The objective of this study was to determine whether in utero exposure to Bisphenol A (BPA) induced reproductive tract abnormalities in the adult male testis. Using the C57/Bl6 mouse, we examined sex‐organ weights, anogenital distance, and testis histopathology in adult males exposed in utero via oral gavage to sesame oil, 50 µg/kg BPA, 1000 µg/kg BPA, or 2 µg/kg diethylstilbestrol (DES) as a positive control from gestational days 10 to 16. No changes in sperm production or germ cell apoptosis were observed in adult testes after exposure to either chemical. Adult mRNA levels of genes associated with sexual maturation and differentiation, GATA4 and ID2, were significantly lower only in DES‐exposed testes. In summary, the data indicate no gross alterations in spermatogenesis after in utero exposure to BPA or DES. At the molecular level, in utero exposure to DES, but not BPA, leads to decreased mRNA expression of genes associated with Sertoli cell differentiation. Birth Defects Res (Part B) 92:526–533, 2011. © 2011 Wiley Periodicals, Inc.     

Perinatal BPA exposure demasculinizes males in measures of affect but has no effect on water maze learning in adulthood

Bisphenol A (BPA) is an endocrine disrupting agent that can alter the normal gonadal steroid-sensitive sexual differentiation of the brain and behavior. While reproductive behavior and physiology are known to be altered by perinatal exposure to this compound, less is known about BPA's effects on sex differences in learning and measures of affect. In order to evaluate the effects of perinatal BPA treatment on learning and affect in adulthood, we exposed rats to one of five doses of BPA through gestation and lactation then examined adult behavior in the Morris Water Maze (MWM), the Elevated Plus Maze (EPM) and the Forced Swim Test (FST). No effect of BPA was observed in the MWM, but on both the EPM and FST, low doses (5 μg/kg) of BPA eliminated sex differences found between controls; furthermore, a non-monotonic dose-response observed in previous studies was confirmed for these tasks. Overall, our study adds to the growing data suggesting that BPA interferes with the normal development of affective behaviors in a non-linear, dose-dependent manner.     

Developmental exposure to low-dose estrogenic endocrine disruptors alters sex differences in exploration and emotional responses in mice

Estrogenic endocrine disruptors (EEDs) are naturally occurring or man-made compounds present in the environment that are able to bind to estrogen receptors and interfere with normal cellular development in target organs and tissues. There is mounting evidence that EEDs can interfere with the processes of sexual differentiation of brain and behavior in different animal models. We investigated the effects of maternal exposure to EEDs, at concentrations within the range of human exposure and not patently teratogenic, on behavioral responses of male and female house mice (Mus musculus domesticus) before and after puberty. Pregnant dams were trained to spontaneously drink daily doses of corn oil with or without the estrogenic plastic derivative, bisphenol A (BPA 10 microg/kg), or the estrogenic insecticide methoxychlor (MXC 20 microg/kg) from gestation day 11 to postpartum day 8. Their male and female offspring were examined at different ages to examine several components of explorative and emotional behaviors in 3 experimental paradigms: a novelty test before puberty and, as adults, a free-exploratory open-field test and the elevated plus maze test. The main results are sex differences in control mice on a number of behavioral responses at both ages and in all experimental paradigms, while perinatal exposure to BPA or MXC decreased or eliminated such sex differences. The present findings are evidence of long-term consequences of developmental exposure to BPA and MXC on neurobehavioral development and suggest a differential effect of low-dose exposure to these estrogenic chemicals in males and females.     

Inflammatory repercussions in female steroid responsive glands after perinatal exposure to bisphenol A and 17-β estradiol

The mammary gland (MG) and female prostate are plastic reproductive organs which are highly responsive to hormones. Thus, endocrine disruptors, such as bisphenol A (BPA) and exogenous estrogens, negatively affect glandular homeostasis. In addition to previously described alterations, changes in inflammatory markers expression also trigger the development of a microenvironment that contributes to tumor progression. The current work aimed to evaluate the inflammatory responses of the MG and prostate gland to BPA (50 µg/kg) and 17-β estradiol (35 µg/kg) exposure during the perinatal window of susceptibility. The results showed that at 6 months of age there was an increase in the number of phospho-STAT3 (P-STAT3) positive cells in the female prostate from animals perinatally exposed to 50 µg/kg BPA daily. In addition, the number of macrophages increased in these animals in comparison with nonexposed animals, as shown by the F4/80 marker. Despite an increase in the incidence of lobuloalveolar and intraductal hyperplasia, the MG did not show any difference in the expression of the four inflammatory markers evaluated: tumor necrosis factor-α, COX-2, P-STAT3, and F4/80. Analysis of both glands from the same animal led to the conclusion that exposure to endocrine disruptors during the perinatal window of susceptibility leads to different inflammatory responses in different reproductive organs. As the prostate is more susceptible to these inflammatory mechanisms, it is reasonable to affirm that possible neoplastic alterations in this organ are related to changes in the inflammatory pattern of the stroma, a characteristic that is not evident in the MG.     

妊娠期和哺乳期双酚A暴露对幼年子代小鼠焦虑和抑郁行为的影响

双酚A(bisphenol-A,BPA)对脑和行为发育的低剂量效应已引起广泛关注。本研究分别于妊娠最后2周和分娩后前2周母鼠灌胃BPA(0.4和4 mg/kg.d),然后以旷场、高架十字迷宫、明暗箱、镜子迷宫、强迫游泳和被动回避箱等模型,分别测试幼年期(生后21～28 d)子代小鼠的行为,探讨围生期不同阶段的BPA暴露对幼年仔鼠自发活动、探究、焦虑、抑郁和被动回避记忆等行为的影响。结果表明,围生期不同阶段的BPA暴露对这些行为的影响不同,主要表现为:妊娠期BPA暴露促进幼年仔鼠的活动性,减弱其焦虑状态,提高雄性仔鼠的探究能力,促进雌性仔鼠的被动回避记忆;哺乳期BPA暴露减少幼年仔鼠的活动性,但对其焦虑行为的影响相对较弱,不影响仔鼠的探究能力和被动回避记忆;而妊娠期和哺乳期BPA暴露均加剧幼年仔鼠的抑郁行为。以上结果提示,妊娠期和哺乳期BPA暴露均可影响幼年仔鼠的焦虑、抑郁、被动回避记忆等多种行为,而妊娠期可能是BPA影响的更敏感时期。     

DNA methylome changes by estradiol benzoate and bisphenol A links early-life environmental exposures to prostate cancer risk

Developmental exposure to endocrine-disrupting chemicals (EDCs), 17β-estradiol-3-benzoate (EB) and bisphenol A (BPA), increases susceptibility to prostate cancer (PCa) in rodent models. Here, we used the methylated-CpG island recovery assay (MIRA)-assisted genomic tiling and CpG island arrays to identify treatment-associated methylome changes in the postnatal day (PND)90 dorsal prostate tissues of Sprague-Dawley rats neonatally (PND1, 3, and 5) treated with 25 µg/pup or 2,500 µg EB/kg body weight (BW) or 0.1 µg BPA/pup or 10 µg BPA/kg BW. We identified 111 EB-associated and 86 BPA-associated genes, with 20 in common, that have significant differentially methylated regions. Pathway analysis revealed cancer as the top common disease pathway. Bisulfite sequencing validated the differential methylation patterns observed by array analysis in 15 identified candidate genes. The methylation status of 7 (Pitx3, Wnt10b, Paqr4, Sox2, Chst14, Tpd52, Creb3l4) of these 15 genes exhibited an inverse correlation with gene expression in tissue samples. Cell-based assays, using 5-aza-cytidine-treated normal (NbE-1) and cancerous (AIT) rat prostate cells, added evidence of DNA methylation-mediated gene expression of 6 genes (exception: Paqr4). Functional connectivity of these genes was linked to embryonic stem cell pluripotency. Furthermore, clustering analyses using the dataset from The Cancer Genome Atlas revealed that expression of this set of 7 genes was associated with recurrence-free survival of PCa patients. In conclusion, our study reveals that gene-specific promoter methylation changes, resulting from early-life EDC exposure in the rat, may serve as predictive epigenetic biomarkers of PCa recurrence, and raises the possibility that such exposure may impact human disease.     

Perinatal exposure to bisphenol-A impairs learning-memory by concomitant down-regulation of N-methyl-d-aspartate receptors of hippocampus in male offspring mice

Bisphenol-A (BPA) has been shown to influence development of the brain and behaviors. The purpose of the present report was to investigate the effects of perinatal exposure to BPA on learning/memory and its mechanism of action, especially focusing on N-methyl-d-aspartate receptor (NMDAR). Perinatal maternal exposure to BPA at 0.5, 5, and 50 mg/kg/d significantly extended the escape length to find the hidden platform in Morris water maze, and BPA at 0.5 or 5 mg/kg/d markedly decreased the percentage of time spent in the quadrant where the platform had been during training both in postnatal day (PND) 21 and PND 56 mice. The results of passive avoidance test showed that the error frequency to step down from a platform after received footshock was significantly increased, and the latency of the step-down response onto the grid floor 24 h after received footshock was obviously reduced by exposure to BPA at 5 and 50 mg/kg/d (P < 0.01) in the PND 21 offspring or at 50 mg/kg/d in the PND 56 offspring (P < 0.01). Furthermore, perinatal exposure to BPA significantly inhibited the expressions of NMDAR subunits NR1, NR2A, and 2B in the hippocampus during the development stage, especially in PND 56 mice. The expressions of estrogen receptor beta (ERβ) in both PND 21 and PND 56 mice were markedly down-regulated by BPA at 0.5, 5, and 50 mg/kg/d. These results indicate that perinatal exposure to BPA affects normal behavioral development in both spatial memory and avoidance memory, and also permanently influences the behavior of offspring in adulthood. The inhibition of expressions of NMDAR subunits and ERβ in hippocampus during postnatal development stage may be involved.     

Gestational exposure to bisphenol A and cross-fostering affect behaviors in juvenile mice

Bisphenol-A (BPA) is a component of polycarbonate resins, and, lately, concern has been raised about its potential negative effects on human health. BPA is an estrogen analog and, in addition, it can act as a DNA hypomethylator. We examined the effects of gestational exposure to BPA on several behaviors in C57BL/6J mice. Because BPA affects maternal care, which, may have long-lasting effects on offspring behavior, we tested mice raised by either biological or fostered dams. Both diet and dam affected behavior in juvenile mice in a social novelty task and the elevated plus maze (EPM). In a social novelty task, the amount of time spent interacting with an adult male was affected by sex and gestational diet, but only in juveniles raised by a foster dam. Control females spent less time sniffing a novel adult than did control males or females exposed to BPA during gestation. In the EPM, juveniles reared by foster dams and exposed to BPA during gestation spent less time in the distal half of the open arm as compared with juveniles gestated on a control diet. Adult offspring raised by their biological dams showed the same response pattern; gestational BPA increased anxiety as compared with control diet. Our results show that prenatal BPA exposure affects social behavior and anxiety in the EPM. Moreover, some facet(s) of the infant–maternal interaction may modify these effects.     

Pre- and postnatal bisphenol A treatment results in persistent deficits in the sexual behavior of male rats, but not female rats, in adulthood

Perinatal administration of the endocrine disruptor bisphenol A (BPA) reportedly inhibits the sexual behavior of sexually naïve adult male rats. In order to evaluate the effects of BPA administration during early development on later reproductive behavior, we administered one of five doses of bisphenol A daily to pregnant female rats throughout gestation and lactation, and quantified the appetitive and consummatory sexual behaviors of the resultant male and female offspring over multiple sexual encounters in adulthood. Males receiving low dose perinatal BPA (50 μg/kg bw/day) showed persistent deficits in sexual behavior in adulthood. Males receiving the highest dose (5 mg/kg bw/day), however, were indistinguishable from controls with respect to consummatory sexual behaviors but showed decreased latencies to engage in those behaviors when sexually naïve, with significant non-linear, or U-shaped, dose-response relationships observed on the first and last day of testing. Adult female sexual behavior was not affected by early BPA administration at any dose tested. These results are consistent with previous reports that BPA exerts behavioral effects especially at low doses, and further indicates that BPA can cause lasting impairment of sexual behavior in males, but does not alter the normal development of female appetitive or consummatory sexual behaviors. To our knowledge, this is the first report indicating that adult sexual performance is impaired in sexually experienced animals following perinatal exposure to bisphenol A.     

Proteomic analysis in mammary glands of rat offspring exposed in utero to bisphenol A

Bisphenol A (BPA) is a ubiquitous environmental contaminant with established endocrine disruptor properties. The objective of our study was to determine the effects of prenatal exposure to BPA on the rat mammary gland proteome in postnatal rats as a first step toward the investigation of translational biomarkers of susceptibility in the human population. Pregnant rats were treated orally with 0, 25 or 250 µg BPA/kg body weight from days 10 to 21 post-conception. Female offspring were euthanized at 21 and 50 days, and mammary glands were collected. Proteomic analysis was conducted using 2-DE, followed by a combination of MALDI-TOF–TOF and LC–MS/MS, which led to the identification of 21 differentially abundant proteins including vimentin, SPARC and 14–3–3. Western blot analysis of key downstream signaling proteins demonstrated increased phospho-AKT, c-Raf, phospho-ERKs-1 and 2, but decreased TGF-β in mammary glands of 50 day old rats exposed prenatally to BPA. Our studies indicate for the first time that key proteins involved in signaling pathways such as cellular proliferation are regulated at the protein level by BPA. This data is expected to aid in the understanding of how BPA may be influencing the susceptibility of the mammary gland to cancer transformation.     

Gestational exposure to low dose bisphenol A alters social behavior in juvenile mice

Bisphenol A (BPA) is a man-made compound used to make polycarbonate plastics and epoxy resins; public health concerns have been fueled by findings that BPA exposure can reduce sex differences in brain and some behaviors. We asked if a low BPA dose, within the range measured in humans, ingested during pregnancy, would affect social behaviors in prepubertal mice. We noted sex differences in social interactions whereby females spent more time sitting side-by-side, while males engaged in more exploring and sitting alone. In addition BPA increased display of nose-to-nose contacts, play solicitations and approaches in both sexes. Interactions between sex and diet were found for self grooming, social interactions while sitting side-by-side and following the other mouse. In all these cases interactions were produced by differences between control and BPA females. We examined brains from embryos during late gestation to determine if gene expression differences might be correlated with some of the sexually dimorphic or BPA affected behaviors we observed. Because BPA treatments ended at birth we took the brains during embryogenesis to increase the probability of discovering BPA mediated effects. We also selected this embryonic age (E18.5) because it coincides with the onset of sexual differentiation of the brain. Interestingly, mRNA for the glutamate transporter, Slc1a1, was enhanced by exposure to BPA in female brains. Also we noted that BPA changed the expression of two of the three DNA methyltransferase genes, Dnmt1 and Dnmt3a. We propose that BPA affects DNA methylation of Sc1a1 during neural development. Sex differences in juvenile social interactions are affected by BPA and in particular this compound modifies behavior in females.     

Human health risk assessment and source diagnosis of polycyclic aromatic hydrocarbons (PAHs) in the corn and agricultural soils along main roadside in Changchun,China

This work was to investigate distribution characteristics, human health risk assessment, and possible sources of 16 priority polycyclic aromatic hydrocarbons (PAHs) in corn and surface soils of farmlands along main roadside in Changchun City, Jilin Province, China. Total concentrations of 16 PAHs ranged from 1572.4 to 4390.2 µg/kg with a mean value of 2954.9 µg/kg in soils and from 219.9 to 627 µg/kg with a mean value of 362µg/kg in corn. Light-molecular-weight PAHs (2–3 rings) concentration was dominant in soils, accounting for 51%, whereas high-molecular-weight PAHs (5–6 rings) concentration was highest in corn, accounting for 48%. The results of plant concentration factor indicated that high-molecular-weight PAHs have greater mobility. To evaluate potential risk to human health, hazard index (HI) and risk index (RI) were employed. The values of HI for corn and soils were both smaller than 1, indicating that exposure of PAHs posed no or little potential risk to local residents. The fact that values of RI for corn and soils were smaller than 1 × 10^–4 suggested that exposure of PAHs posed no or little cancer risk to local residents. The possible sources of PAHs in corn and soils were both identified as mixture patterns of pyrogenic and petrogenic sources.     

Bisphenol A induces permanent squamous change in mouse prostatic epithelium

Bisphenol A (BPA) is a monomer of plastic products widely used in daily life, and has weak estrogenic activity. In this study, male BALB/c mice were treated with BPA and diethylstilbestrol (DES) in adult and fetal periods to investigate whether BPA could affect prostatic epithelial differentiation. Eight-to 9-week-old mice treated for 3 weeks with subcutaneous implants of 0.2-200 mg BPA pellets induced the expression of cytokeratin 10 (CK10) in prostatic basal epithelial cells in a dose-dependent manner. Utilizing organ culture of adult prostate, 1 nM and 1 microM BPA also induced CK10 expression and squamous metaplasia with multilayering of basal epithelial cells, respectively. Fetal exposure to low-dose BPA (20 microg/kg/day) from gestation day (GD) 13 to GD18 induced permanent CK10 expression in basal cells of the adult prostate similar to DES (0.2 microg/kg/day). These results indicate that in mouse, BPA can directly elicit CK10 expression in prostatic epithelium, and that this change can be elicited by doses as low as 20 microg/kg/day. We speculate that low-dose BPA during fetal life may also induce permanent squamous change in human prostate.     

Galangin treatment during dendritic cell differentiation confers tolerogenic properties in response to lipopolysaccharide stimulation

Tolerogenic dendritic cells (tolDCs) can induce the differentiation of immunosuppressive regulatory T cells and are therefore candidates for the prevention or treatment of various inflammatory diseases. Galangin, a major component of propolis and Alpinia officinarum, has well-established anti-inflammatory effects, but its ability to induce a tolerogenic state in DCs has not been demonstrated. In this study, we investigated the effects of galangin on DC differentiation and immune responses. In particular, we compared phenotypic and functional differences between DCs (Gal-DCs) generated by galangin treatment during DC differentiation and bone marrow-derived DCs. Gal-DCs were generated by adding culture medium containing various doses of galangin (1.8–18.5 µM) on 3 and 6 day. Upon lipopolysaccharide (100 ng/mL) stimulation for 24 h, Gal-DCs generated with 7.4 µM galangin treatment showed lower levels of CD86 and lower major histocompatibility complex class II antigen-presentation than those of bone marrow-derived DCs. Furthermore, Gal-DCs showed markedly increased programmed death ligand 1 expression and IL-10 production via the activation of mitogen-activated protein kinases. Interestingly, Gal-DCs co-cultured with allogeneic CD4 T cells exhibited the reduced cell proliferation and differentiation into Th1-, Th2-, and Th17-type cell; instead, Gal-DCs contributed to the induction of CD4⁺CD25⁺Foxp3⁺ Tregs. Taken together, our data suggest that exposure to galangin during DC differentiation confers tolerogenic properties, efficiently inducing Th cell differentiation to immunosuppressive Tregs. These findings provide new insights into the molecular mechanism underlying the anti-inflammatory effects of galangin on DCs.     

Effects of developmental exposure to bisphenol A on spatial navigational learning and memory in rats: A CLARITY-BPA study

Bisphenol A (BPA) is a ubiquitous industrial chemical used in the production of a wide variety of items. Previous studies suggest BPA exposure may result in neuro-disruptive effects; however, data are inconsistent across animal and human studies. As part of the Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY-BPA), we sought to determine whether female and male rats developmentally exposed to BPA demonstrated later spatial navigational learning and memory deficits. Pregnant NCTR Sprague–Dawley rats were orally dosed from gestational day 6 to parturition, and offspring were directly orally dosed until weaning (postnatal day 21). Treatment groups included a vehicle control, three BPA doses (2.5 μg/kg body weight (bw)/day—[2.5], 25 μg/kg bw/day—[25], and 2500 μg/kg bw/day—[2500]) and a 0.5 μg/kg/day ethinyl estradiol (EE)-reference estrogen dose. At adulthood, 1/sex/litter was tested for seven days in the Barnes maze. The 2500 BPA group sniffed more incorrect holes on day 7 than those in the control, 2.5 BPA, and EE groups. The 2500 BPA females were less likely than control females to locate the escape box in the allotted time (p value = 0.04). Although 2.5 BPA females exhibited a prolonged latency, the effect did not reach significance (p value = 0.06), whereas 2.5 BPA males showed improved latency compared to control males (p value = 0.04), although the significance of this result is uncertain. No differences in serum testosterone concentration were detected in any male or female treatment groups. Current findings suggest developmental exposure of rats to BPA may disrupt aspects of spatial navigational learning and memory.     

Estimation of whole‐body SAR from electromagnetic fields using personal exposure meters

In this article, personal electromagnetic field measurements are converted into whole‐body specific absorption rates for exposure of the general public. Whole‐body SAR values calculated from personal exposure meter data are compared for different human spheroid phantoms: the highest SAR values (at 950 MHz) are obtained for the 1‐year‐old child (99th percentile of 17.9 µW/kg for electric field strength of 0.36 V/m), followed by the 5‐year‐old child, 10‐year‐old child, average woman, and average man. For the 1‐year‐old child, whole‐body SAR values due to 9 different radiofrequency sources (FM, DAB, TETRA, TV, GSM900 DL, GSM1800 DL, DECT, UMTS DL, WiFi) are determined for 15 different scenarios. An SAR matrix for 15 different exposure scenarios and 9 sources is provided with the personal field exposure matrix. Highest 95th percentiles of the whole‐body SAR are equal to 7.9 µW/kg (0.36 V/m, GSM900 DL), 5.8 µW/kg (0.26 V/m, DAB/TV), and 7.1 µW/kg (0.41 V/m, DECT) for the 1‐year‐old child, with a maximal total whole‐body SAR of 11.5 µW/kg (0.48 V/m) due to all 9 sources. All values are below the basic restriction of 0.08 W/kg for the general public. 95th percentiles of whole‐body SAR per V/m are equal to 60.1, 87.9, and 42.7 µW/kg for GSM900, DAB/TV, and DECT sources, respectively. Functions of the SAR versus measured electric fields are provided for the different phantoms and frequencies, enabling epidemiological and dosimetric studies to make an analysis in combination with both electric field and actual whole‐body SAR. Bioelectromagnetics 31:286–295, 2010. © 2009 Wiley‐Liss, Inc.     

Developmental exposure to xenoestrogens at low doses alters femur length and tensile strength in adult mice

Developmental exposure to high doses of the synthetic xenoestrogen diethylstilbestrol (DES) has been reported to alter femur length and strength in adult mice. However, it is not known if developmental exposure to low, environmentally relevant doses of xenoestrogens alters adult bone geometry and strength. In this study we investigated the effects of developmental exposure to low doses of DES, bisphenol A (BPA), or ethinyl estradiol (EE(2)) on bone geometry and torsional strength. C57BL/6 mice were exposed to DES, 0.1 μg/kg/day, BPA, 10 μg/kg/day, EE(2), 0.01, 0.1, or 1.0 μg/kg/day, or vehicle from Gestation Day 11 to Postnatal Day 12 via a mini-osmotic pump in the dam. Developmental Xenoestrogen exposure altered femoral geometry and strength, assessed in adulthood by micro-computed tomography and torsional strength analysis, respectively. Low-dose EE(2), DES, or BPA increased adult femur length. Exposure to the highest dose of EE(2) did not alter femur length, resulting in a nonmonotonic dose response. Exposure to EE(2) and DES but not BPA decreased tensile strength. The combined effect of increased femur length and decreased tensile strength resulted in a trend toward decreased torsional ultimate strength and energy to failure. Taken together, these results suggest that exposure to developmental exposure to environmentally relevant levels of xenoestrogens may negatively impact bone length and strength in adulthood.     

Effect of bisphenol A toxicity on growth performance,biochemical variables,and oxidative stress biomarkers of Nile tilapia,Oreochromis niloticus (L.)

Bisphenol A (BPA) is one of the industrial chemical compound which is used in the production of polycarbonate plastics and epoxy resins. BPA is used throughout the world and it could enter the aquatic ecosystems causing serious problems. To evaluate the potential effects of BPA toxicity on Nile tilapia, Oreochromis niloticus (L.) performance, its lethal concentration (LC₅₀) was determined and it was 13.13 µg/L. After that, fish (33.9 ± 0.55 g/fish) were exposed to 0.0, 1.64, or 3.28 µg/L of BPA for 6 weeks after which growth performance, biochemical variables, and oxidative defense system were assessed. The results showed that fish growth and feed intake were significantly reduced as BPA levels increased with no significant difference in fish survival. Total protein, albumin, globulin, and acetylcholine esterase decreased significantly; meanwhile, aspartate transferase, alanine transferase, alkaline phosphatase, uric acid, and creatinine increased significantly with exposure to BPA in a dose dependent manner. Furthermore, malondialdehyde value and the activities of superoxide dismutase and catalase increased significantly; while glutathione peroxidase and glutathione S‐transferase decreased significantly as BPA levels increased. In conclusion, BPA exposure in aquatic environment deteriorated fish performance and health causing liver and kidney dysfunction. Thus, fish exerted oxidative defense enzymes as a protection tool against BPA toxicity.     

Health risk assessment from dermal exposure to pesticide residues on vegetables among greengrocers in fresh market,Bangkok, Thailand

Pesticide residues (PRs) in market vegetables have been reported regularly. Greengrocers may be exposed to several sorts of PRs on vegetables through hand contact. Health risk assessment from occupational exposure to PRs on vegetables is particularly concerning. This study was conducted among 91 vegetable vendors at a large fresh market in Bangkok. Hand wipe samples were collected in the dry season to extract and analyze PRs including organophosphates (OPs), pyrethroids (PYs), and carbamates (CAs) by gas chromatography (GC-FPD/GC-μECD) and liquid chromatography (LC–MS). The results showed that all wipe samples contained OPs, PYs, and CAs, mainly chlorpyrifos (0.01–0.14 µg/hands) and cypermethrin (0.42–11.64 µg/hands). The frequently detected PRs were aldicarb (87.2%), carbofuran (69.2%), permethrin (63.7%), and profenofos (60.0%). At 99th percentile values of PR exposure, average daily dose was 2.42 × 10^?5 mg/kg/d and hazard index did not exceed the acceptable level (0.287). Glove wearing, hand washing, and work-related factors were significantly associated with PRs on hands after adjusted for gender (p-value < 0.05). Greengrocers may therefore not be at risk from PRs on vegetables and exposure via hands during their work. However, these findings suggest that proper personal hygiene practices among greengrocers should be considered to prevent them from PR exposure and potential health risks.