Intake of bisphenol A from canned beverages and foods on the Belgian market

Effect of bisphenol F, an analog of bisphenol A, on the reproductive functions of male rats

OBJECTIVE

Bisphenol A (BPA) is a monomer primarily used in the production of polycarbonate plastic and epoxy resins. Bisphenol F (BPF) is apparently the main BPA replacement that is used increasingly. BPF has been detected in canned food, thermal paper receipts, and soft drinks. In the present experiment, we did both in vitro and in vivo studies to evaluate the effect of low and high-dose BPF exposures on testosterone concentration, oxidative stress, and antioxidants activity in reproductive tissues of male rats.

METHODS

Adult (80-90 days old) male Sprague Dawley rats (n = 36) obtained from the rodent colony of Animal Sciences Department of Quaid-i-Azam University. The direct effects of BPF on the antioxidant enzymes and testosterone secretion were measured in vitro and in vivo studies. In an in vivo experiment, adult male Sprague Dawley rats (n = 42) were exposed to different concentrations of bisphenol F (1, 5, 25, and 50 mg/kg/d) for 28 days. Various biochemical parameters were analyzed including the level of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), reactive oxygen species (ROS), and lipid peroxidation (LPO). Moreover, sperm motility, daily sperm production (DSP), comet assay, and histological analysis were performed.

RESULTS

In vitro study showed that BPF exposure significantly (p < 0.05) induced oxidative stress biomarkers, i.e., ROS and LPO, while it did not change antioxidant enzyme and testicular testosterone concentration. Whereas, an in vivo study revealed that BPF induced dose-dependent effect and high-dose (100 mg/kg) exposure of BPF significantly reduced tissue protein (p < 0.05) content, CAT (p < 0.001), SOD (p < 0.05), and POD (p < 0.05) levels while significantly (p < 0.05) augmented ROS and lipid peroxidation. Furthermore, BPF reduces testosterone, LH, and FSH secretion in a dose-dependent manner. Significant (p < 0.001) reduction in plasma and intra-testicular testosterone, LH, and FSH was noticed at 100 mg/kg BFP dose. High-dose exposure reduces spermatogenesis.

CONCLUSION

BPF showed an antagonistic effect on male reproductive hormones and induce alterations in testicular morphology. Increased oxidative stress and decreased testicular antioxidant status might be the underlying mechanism of BFP-induced testicular toxicity.

Risk characterization of bisphenol-A in the Slovenian population starting from human biomonitoring data

The current study aims to characterize exposure and risk associated to bisphenol-A (BPA) exposure in Slovenia, starting from biomonitoring data. Based on the urinary data, daily intake for the individuals was back-calculated using a physiology based biokinetic (PBBK) model properly parameterized for BPA, coupled with an exposure reconstruction algorithm. Re-running the PBBK model in forward mode allowed the estimation of biologically effective dose (free plasma BPA) and the respective daily area under the curve (AUC). Finally, risk characterization ratio was derived using both external and internal dose metrics. The urinary BPA levels were found low, with GM of 0.79, 1.51 and 0.20 μg/g creatinine for mothers, children and fathers respectively, similar to the levels of other European countries. Based on the above and accounting for the dynamics of exposure and biokinetics, daily intake was estimated, median exposure levels have been estimated equal to 0.019, 0.035 and 0.005 μg/kg_bw/d for mothers, fathers and children respectively. The highest estimated intake level was found in a child, equal to 0.87 μg/kg_bw/d, while the maximum intake for mothers and fathers were 0.7 and 0.8 μg/kg_bw/d respectively. The respective RCR levels using the EFSA t-TDI of 4 μg/kg_bw/d were 2 magnitudes of order lower below 1, independently of the selected method. It has to be noted that had daily intake been estimated solely based on the urinary concentrations mass balance, the estimated intake would be lower, as a result of the oversimplification on exposure and elimination time dynamics. This highlights the importance for using PBBK modelling based exposure reconstruction schemes for rapidly metabolized and excreted compounds such as BPA, as well as the study design of efficient sampling for rapidly metabolized compounds.

Advancing Chemical Risk Assessment through Human Physiology-Based Biochemical Process Modeling

Physiology-Based BioKinetic (PBBK) models are of increasing interest in modern risk assessment, providing quantitative information regarding the absorption, metabolism, distribution, and excretion (ADME). They focus on the estimation of the effective dose at target sites, aiming at the identification of xenobiotic levels that are able to result in perturbations to the biological pathway that are potentially associated with adverse outcomes. The current study aims at the development of a lifetime PBBK model that covers a large chemical space, coupled with a framework for human biomonitoring (HBM) data assimilation. The methodology developed herein was demonstrated in the case of bisphenol A (BPA), where exposure analysis was based on European HBM data. Based on our calculations, it was found that current exposure levels in Europe are below the temporary Tolerable Daily Intake (t-TDI) of 4 μg/kg_bw/day proposed by the European Food Safety Authority (EFSA). Taking into account age-dependent bioavailability differences, internal exposure was estimated and compared with the biologically effective dose (BED) resulting from translating the EFSA temporary total daily intake (t-TDI) into equivalent internal dose and an alternative internal exposure reference value, namely biological pathway altering dose (BPAD); the use of such a refined exposure metric, showed that environmentally relevant exposure levels are below the concentrations associated with the activation of biological pathways relevant to toxicity based on High Throughput Screening (HTS) in vitro studies.

Urinary bisphenol A in children, mothers and fathers from Slovenia: Overall results and determinants of exposure

In the present study, urinary bisphenol A (BPA) levels were reported for the first time in the Slovenian general population and were evaluated with regard to dietary and non-dietary exposure sources, and compared according to age, gender and area of residence. First morning urine was collected from children (6-11 years), their mothers (30-52 years) and fathers (30-53 years), living in urban and rural areas of Slovenia. Besides basic questionnaire data on general population characteristics, socio-economic status and dietary habits, BPA-specific data was also collected, including consumption of food and beverages from plastic and canned containers, presence of white dental fillings, the use of specific consumer products and hormonal treatments. Urine samples were analysed for both free and conjugated BPA using GC-MS/MS. The urinary levels of total BPA in children, mothers and fathers were low, with geometric means of 1.51, 0.79, and 0.20 μg/g creatinine, respectively. The levels were comparable with the levels reported for other European countries and were all below the current health-based guidance values. In line with large-scale surveys, the data revealed age-dependant BPA urinary levels, with the highest levels in the youngest age group. In mothers, urinary levels of BPA were determined by hormonal interactions more than dietary sources, while a positive association between urinary BPA and diet was apparent in children (canned food/drink and food from plastic material) and fathers (canned food/drink). The study clearly shows that physiological and behavioural differences account for differences in levels of urinary BPA among study groups, a finding that sets the priorities for future research.

Early-life exposure to endocrine disrupting chemicals associates with childhood obesity

Increasing prevalence of childhood obesity poses threats to the global health burden. Because this rising prevalence cannot be fully explained by traditional risk factors such as unhealthy diet and physical inactivity, early-life exposure to endocrine disrupting chemicals (EDCs) is recognized as emerging novel risk factors for childhood obesity. EDCs can disrupt the hormone-mediated metabolic pathways, affect children's growth and mediate the development of childhood obesity. Many organic pollutants are recently classified to be EDCs. In this review, we summarized the epidemiological and laboratory evidence related to EDCs and childhood obesity, and discussed the possible mechanisms underpinning childhood obesity and early-life exposure to non-persistent organic pollutants (phthalates, bisphenol A, triclosan) and persistent organic pollutants (dichlorodiphenyltrichloroethane, polychlorinated biphenyls, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances). Understanding the relationship between EDCs and childhood obesity helps to raise public awareness and formulate public health policy to protect the youth from exposure to the harmful effects of EDCs.

Bisphenol A: Food Exposure and Impact on Human Health

Bisphenol A (BPA) is an industrial compound used extensively to produce synthetic polymers, such as epoxy resins, which are incorporated into the inner coating of metal cans, and also to manufacture polycarbonates with applications in bottles, including bottles of water. Several studies have reported on the transfer of this compound to food. Regarding human exposure to BPA, food intake can be considered the most serious among all the routes, not only because it potentially reaches more people in different age groups (including infants, an especially vulnerable group), but also because it inadvertently occurs over long time periods. BPA is considered an endocrine disruptor and several studies have proposed a relationship between exposure to BPA and the appearance of adverse health effects, such as cancer, infertility, diabetes, and obesity, among others. In 2015 however, the European Food Safety Authority concluded in its last scientific opinion that this compound does not pose any risk to the exposed population's health. Therefore, the EU regards BPA as an authorized product to be used as food contact material. Although BPA intake through food is apparently below the set limits, research into BPA and its potential negative effects is still ongoing. This review contains the most recent in vitro and in vivo studies on BPA toxicity and its harmful effects on health, and it intends to address human exposure to BPA, namely through dietary exposure and its impact on human health.

Differential responses of GC‑1 spermatogonia cells to high and low doses of bisphenol A

Bisphenol A (BPA) is an environmental endocrine disruptor. The exact effect of BPA on spermatogenesis and the specific epigenetic effects on mouse spermatogonia remain to be elucidated. The present study exposed the GC‑1 spermatogonial cell line to a series of differing BPA concentrations and examined the subsequent effects on cell proliferation, mitogen activated protein kinase (MAPK) signaling, DNA and histone methylation. A Cell Counting Kit‑8 assay revealed that BPA significantly inhibited cell growth at the concentration of 10 µg/ml, however no significant alterations were detected at lower BPA doses. The global DNA methylation levels were reduced at the dose of 10 µg/ml of BPA, via detection of 5‑methylcytosine using a dot blot. The protein and mRNA expression levels of DNA methyltransferase (DNMT) 1 were decreased at 10 and 1 µg/ml of BPA, detected via western blotting and reverse transcription‑quantitative polymerase chain reaction, respectively. The global levels of H3K27me3 was decreased at 10 µg/ml BPA, detected via western blotting. Increased phosphorylation of p38 and decreased phosphorylation of extracellular signal‑regulated kinases 1/2 were observed at 10 and 1 µg/ml BPA. The results demonstrated that high and low doses of BPA exposure exhibit differential effects on cell growth, global DNA methylation, histone H3K9Me3 and H3K27Me3 levels and additionally affect the MAPK signaling pathways.

Concentrations of Bisphenols in Canned Foods and Their Risk Assessment in Korea

The purpose of this study was to survey concentrations of bisphenols in canned foods using liquid chromatography-tandem mass spectrometry, to estimate the dietary exposure to bisphenols, and to assess the related risk for the Korean population from the intake of canned foods. The linearity of bisphenols in the range of 2.5 to 725 μg/L was satisfactory with correlation coefficients ( r²) of 0.999. The limit of detection was 0.14 to 5.85 μg/L, and the limit of quantitation was 0.44 to 17.73 μg/L. Sample recoveries were 70.56 to 113.6%, with relative standard deviations below 10% for spiking levels of 50 and 250 μg/kg (15 and 75 μg/kg for BPS). The bisphenol concentrations in 104 canned foods ranged from undetectable to 1,525 μg/kg. The estimated mean daily intake of bisphenols was 0.54 to 78.69 ng/kg of body weight per day, and the 95th percentile daily intake was 1.92 to 134 ng/kg of body weight per day. Therefore, the intake of bisphenols from canned foods for the population in Korea is unlikely to cause human health problems. The analytical methods used are suitable for regular monitoring and assessment of human exposure to bisphenols from foods.

An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling

Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised the demand for plastic materials that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as "additives") contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclates. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times.

The effect of bisphenol A on testicular steroidogenesis and its amelioration by quercetin: an in vivo and in silico approach

Bisphenol A (BPA), a phenyl ring containing synthetic xenoestrogen, is widely used in the manufacture of polycarbonate plastics, epoxy resins and as a non-polymer additive to other plastics. Food is considered as the main source of exposure to BPA as it leaches out from food containers as well as surface coatings. It causes toxicity in the liver, kidney, brain, and other organs by initiating the process of lipid peroxidation. The present investigation was an attempt to evaluate the effect of BPA on steroidogenesis and its amelioration by quercetin. Inbred Swiss strain male albino mice were orally administered with 80, 120 and 240 mg per kg body weight per day of BPA for 45 days. The results revealed that BPA causes significant (p < 0.05) and dose-dependent changes in the body weight and biochemical parameters like protein, cholesterol and lipid contents as well as activities of 3β-and 17β-hydroxysteroid dehydrogenases in the testis of mice. It was also found to significantly reduce the testosterone level in serum. Oral administration of quercetin (30, 60 and 90 mg per kg body weight per day) along with a high dose of BPA (240 mg per kg body weight per day) for 45 days caused significant amelioration in the body weight and steroidogenesis as compared to the BPA alone treated group. The effect was dose-dependent. This amelioration in BPA-induced toxicity might be due to the antioxidative properties of quercetin. The reduction in the function of enzymes was confirmed by in silico bindings. BPA and quercetin show competitive binding with steroidogenic enzymes as well as binding with each other. This could be a possible mechanism to reduce the toxic effect of BPA which has been supported by molecular dynamics simulations for molecular level recognition with structural insights.

Exposure assessment to bisphenol A (BPA) in Portuguese children by human biomonitoring

Exposure to bisphenol A (BPA) is known to be widespread and available data suggests that BPA can act as an endocrine disruptor. Diet is generally regarded as the dominant BPA exposure source, namely through leaching to food from packaging materials. The aim of this study was to evaluate the exposure of 110 Portuguese children (4-18 years old), divided in two groups: the regular diet group (n = 43) comprised healthy normal weight/underweight children with no dietary control; the healthy diet group (n = 67) comprised children diagnosed for obesity/overweight (without other known associated diseases) that were set on a healthy diet for weight control. First morning urine samples were collected and total urinary BPA was analyzed after enzymatic hydrolysis via on-line HPLC-MS/MS with isotope dilution quantification. Virtually, all the children were exposed to BPA, with 91% of the samples above the LOQ (limit of quantification) of 0.1 μg/L. The median (95th percentile) urinary BPA levels for non-normalized and creatinine-corrected values were 1.89 μg/L (16.0) and 1.92 μg/g creatinine (14.4), respectively. BPA levels in the regular diet group were higher than in the healthy diet group, but differences were not significant. Calculated daily BPA intakes, however, were significantly higher in children of the regular diet group than in children of healthy diet group. Median (95th percentile) daily intakes amounted to 41.6 (467) ng/kg body weight/day in the regular diet group, and 23.2 (197) ng/kg body weight/day in the healthy diet group. Multiple logistic regression analysis revealed that children in the healthy diet group had 33% lower intakes than children in the regular diet group (OR 0.67; 95% CI 0.51-0.89). For both groups, however, urinary BPA levels and daily BPA intakes were within the range reported for other children's populations and were well below health guidance values such as the European Food Safety Authority (EFSA) temporary tolerable daily intake (t-TDI) of 4 μg/kg body weight/day. In addition, lower daily BPA intakes were more likely linked with the inherent dietary approach rather than with high BMI or obesity.

Effect of sterilisation and storage conditions on the migration of bisphenol A from tinplate cans of the Lebanese market

The use of bisphenol A (BPA) in lacquer coating of food cans has been restricted by different authorities in many countries, such as in Europe. However, such regulation does not exist in many other countries including Lebanon. Due to the lack of data on the quality of Lebanese can production; this study investigates the migration of BPA from two types of tinplate cans manufactured in Lebanon, before and after sterilisation. Cans were analysed under different storage conditions (time and temperature) and filled with an aqueous simulant. The determination of BPA was carried out using UPLC with fluorescence detection, and further confirmed by MS detection. After sterilisation BPA levels drastically increased from an average of 0.15 to 109 µg/kg, giving a BPA migration around 10.5 µg/dm² for both types of cans. Storage temperature and time had no significant influence on BPA levels in sterilised cans (p-value > 0.05); however, these factors significantly affected BPA levels in non-sterilised cans.

Prenatal exposure estimation of BPA and DEHP using integrated external and internal dosimetry: A case study

Prenatal exposure to Endocrine disruptors (EDs), such as Bisphenol A (BPA) and di (2-ethylhexyl) phthalate (DEHP), has been associated with obesity and diabetes diseases in childhood, as well as reproductive, behavioral and neurodevelopment problems. The aim of this study was to estimate the prenatal exposure to BPA and DEHP through food consumption for pregnant women living in Tarragona County (Spain). Probabilistic calculations of prenatal exposure were estimated by integrated external and internal dosimetry modelling, physiologically based pharmacokinetic (PBPK) model, using a Monte-Carlo simulation. Physical characteristic data from the cohort, along with food intake information from the questionnaires (concentrations of BPA and DEHP in different food categories and the range of the different food ratios), were used to estimate the value of the total dietary intake for the Tarragona pregnancy cohort. The major contributors to the total dietary intake of BPA were canned fruits and vegetables, followed by canned meat and meat products. In turn, milk and dairy products, followed by ready to eat food (including canned dinners), were the most important contributors to the total dietary intake of DEHP. Despite the dietary variations among the participants, the intakes of both chemicals were considerably lower than their respective current tolerable daily intake (TDI) values established by the European Food Safety Authority (EFSA). Internal dosimetry estimates suggest that the plasma concentrations of free BPA and the most important DEHP metabolite, mono (2-ethylhexyl) phthalate (MEHP), in pregnant women were characterized by transient peaks (associated with meals) and short half-lives (< 2h). In contrast, fetal exposure was characterized by a low and sustained basal BPA and MEHP concentration due to a lack of metabolic activity in the fetus. Therefore, EDs may have a greater effect on developing organs in young children or in the unborn child.

Evaluation of Endocrine Disrupting Compounds Migration in Household Food Containers under Domestic Use Conditions

Plasticizers and plastic monomers are commonly used in packaging. Most of them act as endocrine disrupters and are susceptible to migrate from the packaging to the food. We evaluated the migration of endocrine disrupting compounds from three different household food containers to four food simulants under different domestic treatments and for different periods of time, with the aim of reproducing real domestic conditions. The results showed that the migration to the simulants increased with the storage time, up to more than 50 times in certain cases. The heating power seemed to increase the migration processes (up to more than 30 times), and reusing containers produced an increase or decrease of the concentrations depending on the container type and the simulant. The concentrations found were lower than other concentrations reported (always less than 4000 pg/mL, down to less than 20 pg/mL), which might be a consequence of the domestic conditions used.

Bisphenol A in soft drinks and canned foods and data evaluation

Bisphenol A (BPA) is one of the most common industrial chemicals and known to exert endocrine disruption activity. The aim of this study was the quantification of BPA in food stuffs on the Greek market. The applied liquid chromatography-mass spectrometry method was validated for linearity, limit of quantification, accuracy, precision and recovery. About 41.7% of the canned solid phase samples, 25.0% of the canned liquid phase samples and 43.8% of the soft drinks were positive. Mean BPA concentrations (range) were 33.4 ± 4.4 ng/g (4.90 ± 0.64-66.0 ± 8.6 ng/g) in canned solid phase, 2.70 ± 0.08 ng/ml (1.90 ± 0.06-3.50 ± 0.11 ng/ml) in canned liquid phase and 2.30 ± 0.18 ng/ml (0.40 ± 0.03-10.2 ± 0.8 ng/ml) in soft drinks. The results of this study are comparable with those reported in the literature according to which higher concentrations of BPA were detected in the solid fraction of canned food compared to their liquid fraction.

Integrated exposure and risk characterization of bisphenol-A in Europe

The current study aims at a comprehensive risk characterization of bisphenol A (BPA) supported by an integrated exposure modelling framework that comprises far field and near field exposure modelling coupled to a dynamic lifetime PBTK model. Exposure analysis was done on European data of BPA food residues and human biomonitoring (HBM). The latter were further assimilated through an advanced exposure reconstruction modelling framework to estimate the corresponding external and internal systemic dose of BPA and its metabolites. Special attention was paid on the assessment of exposure to BPA during critical developmental stages such as gestation by modelling the mother-fetus toxicokinetic interaction. Our findings showed that current exposure levels in Europe are below the temporary Tolerable Daily Intake (t-TDI) of 4 μg/kg_bw/d proposed by the European Food Safety Authority. Taking into account age-dependent bioavailability differences, internal exposure of premature neonates hosted in intensive care units was reckoned close to the biologically effective dose (BED) resulting from translating the EFSA temporary total daily intake (t-TDI) into equivalent internal dose. Use of the ToxCast21 Biological Pathway Altering Dose (BPAD) as an alternative internal exposure reference value, resulted in increased margins of safety compared to the conventional exposure/risk characterization scheme.

Sensitive Adsorptive Voltammetric Method for Determination of Bisphenol A by Gold Nanoparticle/Polyvinylpyrrolidone-Modified Pencil Graphite Electrode

A novel electrochemical sensor gold nanoparticle (AuNP)/polyvinylpyrrolidone (PVP) modified pencil graphite electrode (PGE) was developed for the ultrasensitive determination of Bisphenol A (BPA). The gold nanoparticles were electrodeposited by constant potential electrolysis and PVP was attached by passive adsorption onto the electrode surface. The electrode surfaces were characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The parameters that affected the experimental conditions were researched and optimized. The AuNP/PVP/PGE sensor provided high sensitivity and selectivity for BPA recognition by using square wave adsorptive stripping voltammetry (SWAdSV). Under optimized conditions, the detection limit was found to be 1.0 nM. This new sensor system offered the advantages of simple fabrication which aided the expeditious replication, low cost, fast response, high sensitivity and low background current for BPA. This new sensor system was successfully tested for the detection of the amount of BPA in bottled drinking water with high reliability.

Bisphenol A in Edible Part of Seafood

Bisphenol A (BPA) is a man-made compound, mainly used as a monomer to produce polycarbonate (PC), epoxy resins, non-polymer additives to other plastics, which have many food related applications, such as food storage containers, tableware and internal coating of cans, as well as non-food applications such as electronic equipment, construction materials and medical devices. BPA exposure can occur when the residual monomer migrates into packaged food and beverages. Moreover, due to the ubiquitous presence of this compound, the general population can be exposed to environmental sources such as water, air and soil. Many studies have investigated the potential health hazards associated with BPA, which can elicit toxic and cancerogenic effects on humans. According to the European Food Safety Authority opinion, diet is considered to be the main source of exposure, especially canned food; moreover, among non-canned food, meat and fish products have the highest levels of BPA contamination. This review focuses on BPA contamination in seafood, analysing worldwide literature (from January 2010 to October 2015) on BPA contamination of edible parts. The authors try to identify differences between canned and non-canned seafood in literature, and gaps in the state of art. The data evaluated underline that all concentrations for both canned and non-canned seafood were below the specific migration limit set by the European Community Directive for BPA in food. Moreover, the canned seafood is more contaminated than the non-canned one.

Bisphenol A in Urine of Chinese Young Adults: Concentrations and Sources of Exposure

Bisphenol A (BPA) is an endocrine disrupting environmental chemical. Urinary concentrations of BPA were measured in samples collected nationwide from Chinese young adults. The geometric mean urinary concentration of BPA in Chinese young adults was 2.23 ng/mL. The estimated daily exposure dose for BPA was 64.8 ng/kg bw/day. Contributions of various BPA sources to exposure in Chinese young adults were estimated. Dietary intake was the primary exposure pathway. The contribution of dietary intake, indoor dust, paper products and personal care products to BPA intake was 72.5 %, 0.74 %, 0.98 %, 0.22 % of the total exposure dose, respectively. This is the first study on the occurrence of BPA in young adults from most provinces and autonomous regions of China. The results can be used to establish a database for BPA exposure assessment for Chinese general population.

Bisphenol A exposure pathways in early childhood: Reviewing the need for improved risk assessment models

Bisphenol A (BPA) is a plasticiser found in a number of household plastics, electronics, and food-packaging materials. Over the past 5 years, several human epidemiological studies have reported a positive association between BPA exposure and adverse health outcomes in children, including obesity, asthma, preterm birth, and neuro-behavioural disturbances. These findings are in conflict with international environmental risk assessment models, which predict daily exposure levels to BPA should not pose a risk to child health. The aim of this review is to provide an overview of the evidence for different exposure sources and potential exposure pathways of BPA in early childhood. By collating the findings from experimental models and exposure associations observed in human bio-monitoring studies, we affirm the potential for non-dietary sources to make a substantial contribution to total daily exposure in young children. Infants and toddlers have distinctive exposure sources, physiology, and metabolism of endocrine-disrupting chemicals. We recommend risk-assessment models implement new frameworks, which specifically address exposure and hazard in early childhood. This is particularly important for BPA, which is present in numerous products in the home and day-care environments, and for which animal studies report contradictory findings on its safety at environmentally relevant levels of exposure.

Human Bisphenol A Exposure and the "Diabesity Phenotype"

Bisphenol A (BPA), a known endocrine disruptor, is a food contaminant suspected of being a contributing factor to the present-day increase in obesity, diabetes, and cardiovascular disease. This issue is of increasing interest in the field of diabetes research and has become a matter of concern for regulatory agencies and food industries. Recently, the number of studies involving BPA has increased exponentially, but there are still many gaps in the knowledge of the relationship between actual BPA exposure and cardiometabolic risk and of the modalities of food intake exposure, all of which prevents sound judgments concerning the risks to human health. This review focuses on the association between human exposure to BPA and obesity, thyroid function, diabetes, insulin resistance, metabolic syndrome, cardiovascular diseases, and BPA content in food. Many cross-sectional studies support, sometimes contradictorily, an adverse effect of BPA exposure on obesity, diabetes, and cardiovascular diseases. Few prospective studies support an adverse effect of BPA exposure on such pathologies. Moreover, no intervention studies have been conducted to evaluate the causality of such associations. This is mainly due to lack of an appropriate database of BPA content in foods, thus hindering any estimation of the usual dietary BPA intake.

Estimating bisphenol A exposure levels using a questionnaire targeting known sources of exposure

OBJECTIVE

To develop a BPA Exposure Assessment Module (BEAM) for use in large observational studies and to evaluate the ability of the BEAM to estimate bisphenol A (BPA) exposure levels.

DESIGN

The BEAM was designed by modifying an FFQ with questions targeting known sources of BPA exposure. Frequency of intake of known dietary sources of BPA was assessed using the BEAM and three 24 h food records as a reference diet measurement tool. Urinary BPA (uBPA) levels were measured as the criterion tool in a pooled urine sample (nine spot samples per participant). Spearman correlations, linear regression and weighted kappa analysis were used to evaluate the ability of the BEAM and food records to estimate BPA exposure levels.

SETTING

Minneapolis/Saint Paul, MN, USA.

SUBJECTS

Sixty-eight healthy adult (20-59 years) volunteers.

RESULTS

Dietary BPA intake assessed by the BEAM was not associated with uBPA levels and was unable to predict participants' rank by uBPA levels. BEAM models with all a priori predictors explained 25 % of the variability in uBPA levels. Canned food intake assessed by food records was associated with uBPA levels, but was unable to rank participants by uBPA levels. Multivariable-adjusted food record models with a priori predictors explained 41 % of the variability in uBPA levels.

CONCLUSIONS

Known dietary sources of BPA exposure explained less than half the variability in uBPA levels, regardless of diet assessment method. Findings suggest that a questionnaire approach may be insufficient for ranking BPA exposure level and additional important sources of BPA exposure likely exist.

Bisphenol A contamination in soft drinks as a risk for children's health in Italy

Bisphenol A (BPA) was determined in sugary carbonated, non-carbonated and milk-based beverages, through HLPC-fluorescence detection and confirmed by LC-MS/MS, in a selection of brands that are mostly consumed by Italian children. The daily intake was determined through the WHO budget method (BM). BPA was found at detectable levels in 57% of carbonated beverages, in 50% of non-carbonated and in 100% of milk-based beverages. The median concentrations were 1.24 µg l(-1) (range = < LOD-4.98 µg l(-1)) in canned carbonated beverages and 0.18 µg l(-1) (< LOD-1.78 µg l(-1)) in non-canned carbonated beverages. In non-carbonated beverages, median concentrations were 0.80 µg l(-1) (< LOD-2.79 µg l(-1)) and 0.18 µg l(-1) (< LOD-3.58 µg l(-1)), respectively, for canned and non-canned beverages; in milk-based products the BPA median concentration was 3.60 µg l(-1) (1.00-17.65 µg l(-1)). BPA daily intake from sugary drink consumption in children ranged from 0.008 to 1.765 µg kg(-1) bw day(-1). The median exposure values for the 'best' and 'worst' cases were 0.16% and 0.47% respectively of the EFSA t-TDI for BPA (4 µg kg(-1) bw day(-1)), and 10.59% and 35.30% of the t-TDI when the maximum levels were considered.

Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures

Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a "canned fraction" parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and underscores the importance of canned foods in the overall exposure of adults of BPA.

Relationship of serum bisphenol A with diabetes in the Thai population, National Health Examination Survey IV, 2009

BACKGROUND

Epidemiological studies of the association between bisphenol A (BPA) exposure and diabetes have been inconsistent. The present study determined serum BPA concentrations in the Thai population and their association with hyperglycemia and diabetes.

METHODS

In all, 2581 serum samples from the Thai National Health Examination Survey (2009) were used to determine BPA levels. Impaired fasting glucose (IFG) was defined as fasting plasma glucose ≥100 and <126 mg/dL. Diabetes was defined as a history of a physician's diagnosis or fasting plasma glucose ≥126 mg/dL. Multinomial logistic regression was used to examine the association of serum BPA with IFG and diabetes.

RESULTS

Of 2581 samples tested, BPA was detected in 2135 samples (weighted percentage 78.1%), with a geometric mean concentration of 0.34 ng/mL BPA. Serum BPA levels were significantly higher among those with diabetes or IFG compared with normoglycemic individuals (0.52 and 0.38 vs 0.33 ng/mL, respectively; P < 0.001). After adjusting for potential confounders, compared with the first quartile (≤0.071 ng/mL), the overall adjusted odds ratios (OR) of serum BPA concentration in the third and fourth quartiles (0.319-0.745 and ≥0.746 ng/mL, respectively) for IFG were 1.72 (95% confidence interval [CI] 1.19, 2.49) and 1.23 (95% CI 0.80, 1.89), respectively; for diabetes, the adjusted OR were 1.88 (95% CI 1.18, 2.99) and 1.83 (95% CI 1.12, 2.95), respectively, with a slightly stronger association among men than in women.

CONCLUSIONS

Serum BPA concentrations were not associated with IFG, but were positively associated with diabetes in the Thai population. Further prospective studies are needed to confirm the relationship.

Levels of bisphenol-A in different paper products in Guangzhou, China, and assessment of human exposure via dermal contact

Bisphenol A (BPA) is a chemical widely used both in plastics production as a food and beverage container and in thermal papers as a color developer. Dietary consumption is the main route of human exposure to BPA, but dermal absorption through handling different papers might be underestimated or ignored. In this study, BPA in different paper products, including different types of papers, receipts and Chinese currencies, were investigated. BPA was detected in receipts (n = 87) and Chinese currencies (n = 46) with concentrations of 0.17-2.675 × 10(4) μg per g paper and 0.09-288.55 μg per g paper, respectively. Except for parchment papers (n = 3), copy papers (n = 3) and food contact papers (n = 3), BPA was measured in all of the other paper products, with levels of 0.01-6.67 μg per g paper. BPA transferred from thermal papers to common papers increased with the increasing contact pressure. Compared with that in water, the migration speed of BPA was doubled in the synthetic sweat. Washing hands could reduce BPA dermal exposure, and washing hands with lotion was the most efficient way. However, about 19-47% of BPA was still found on hands after different washing methods. Dermal absorption via handling of receipts and papers was estimated to be 36.45 ng per day for the general population and 1.54 × 10(-3) to 248.73 μg per day for a cashier. These values are below the maximum doses recommended by the U.S. Environmental Protection Agency and the European Food Safety Authority. However, due to its uncertain adverse effects on human beings, long-term BPA exposure through dermal absorption should be paid more attention, particularly for some occupational populations.

Daily intake of bisphenol A and triclosan and their association with anthropometric data, thyroid hormones and weight loss in overweight and obese individuals

Bisphenol A (BPA) and triclosan (TCS) were determined in urine of Belgian overweight and obese (n=151) and lean (n=43) individuals. After the first urine collection (0M), obese patients started a diet program or have undergone bariatric surgery. Hereafter, three additional urine samples from obese patients were collected after 3 (3M), 6 (6M) and 12 (12M) months. Both compounds were detected in >99% of the samples. BPA had median concentrations of 1.7 and 1.2ng/mL in obese and lean groups, respectively, while TCS had median concentrations of 1.5 and 0.9ng/mL in the obese and lean groups, respectively. The obese group had higher urinary concentrations (ng/mL) of BPA (p<0.5), while no significant differences were found for TCS between the obese and lean groups. No time trends between the different collection moments were observed. The BPA concentrations in the obese group were negatively associated with age, while no gender difference or relationship with body mass index was observed. For TCS, no relationships with gender, BMI, or age were found. The temporal variability of BPA and TCS was assessed with calculation of the intraclass correlation coefficient, Spearman rank correlation coefficients, and surrogate category analysis. We observed evidence that single spot urine samples might be predictive of exposure over a longer period of time. Dietary intakes of BPA and TCS did not differ significantly among the time points considered after obese individuals started losing weight (6 and 12months). Multiple linear regression analyses after adjusting for age and weight loss revealed negative associations between urinary TCS and serum FT4 in the 0M and 3M female obese individuals and positive associations between urinary BPA and serum TSH in the lean group.

Exposure to Bisphenol A From Drinking Canned Beverages Increases Blood Pressure

Bisphenol A (BPA) is a chemical used in plastic bottles and inner coating of beverage cans, and its exposure is almost ubiquitous. BPA has been associated with hypertension and decreased heart rate variability in the previous studies. The aim of the present study was to determine whether increased BPA exposure from consumption of canned beverage actually affects blood pressure and heart rate variability. We conducted a randomized crossover trial with noninstitutionalized adults, who were aged ≥60 years and recruited from a local community center. A total of 60 participants visited the study site 3 times, and they were provided the same beverage in 2 glass bottles, 2 cans, or 1 can and 1 glass bottle at a time. The sequence of the beverage was randomized. We then measured urinary BPA concentration, blood pressure, and heart rate variability 2 hours after the consumption of each beverage. The paired t test and mixed model were used to compare the differences. The urinary BPA concentration increased after consuming canned beverages by >1600% compared with that after consuming glass bottled beverages. Systolic blood pressure adjusted for daily variance increased by ≈4.5 mm Hg after consuming 2 canned beverages compared with that after consuming 2 glass bottled beverages, and the difference was statistically significant. The parameters of the heart rate variability did not show statistically significant differences.The present study demonstrated that consuming canned beverage and consequent increase of BPA exposure increase blood pressure acutely.

24-hour human urine and serum profiles of bisphenol A: Evidence against sublingual absorption following ingestion in soup

Extensive first-pass metabolism of ingested bisphenol A (BPA) in the gastro-intestinal tract and liver restricts blood concentrations of bioactive BPA to <1% of total BPA in humans and non-human primates. Absorption of ingested BPA through non-metabolizing tissues of the oral cavity, recently demonstrated in dogs, could lead to the higher serum BPA concentrations reported in some human biomonitoring studies. We hypothesized that the extensive interaction with the oral mucosa by a liquid matrix, like soup, relative to solid food or capsules, might enhance absorption through non-metabolizing oral cavity tissues in humans, producing higher bioavailability and higher serum BPA concentrations. Concurrent serum and urine concentrations of d6-BPA, and its glucuronide and sulfate conjugates, were measured over a 24hour period in 10 adult male volunteers following ingestion of 30μg d6-BPA/kg body weight in soup. Absorption of d6-BPA was rapid (t1/2=0.45h) and elimination of the administered dose was complete 24h post-ingestion, evidence against any tissue depot for BPA. The maximum serum d6-BPA concentration was 0.43nM at 1.6h after administration and represented <0.3% of total d6-BPA. Pharmacokinetic parameters, pharmacokinetic model simulations, and the significantly faster appearance half-life of d6-BPA-glucuronide compared to d6-BPA (0.29h vs 0.45h) were evidence against meaningful absorption of BPA in humans through any non-metabolizing tissue (<1%). This study confirms that typical exposure to BPA in food produces picomolar to subpicomolar serum BPA concentrations in humans, not nM concentrations reported in some biomonitoring studies.

Biomonitoring of bisphenol A in hair of Greek population

OBJECTIVE

Bisphenol A (BPA) is considered as an endocrine-disruptor in which humans are exposed daily mainly by food-contact products, toys, recycled paper and drinking containers. In this study, we validated a method for the isolation and the detection of BPA in human head hair samples and estimated the burden of BPA in hair of Greek population.

METHODS

Hair samples were collected from 69 volunteers. The isolation of the BPA was performed by solid–liquid extraction with methanol and its determination by a liquid chromatography–mass spectrometry technique.

RESULTS

The limits of quantification (LOQ = 9.7 pg mg(−1)), the accuracy (92.6%), the precision (inter 15.3%, intra 13.0%), the ion suppression (<8.1%) and the recovery (88.3%) of the method were found satisfactory. Differences in the detection rates of the positive samples as well in detected levels of BPA between rural and urban population were observed. The 41.2% of the samples collected from urban population were positive whereas the positive samples from rural population were 14.8% (p = 0.025). The mean concentration of the positive samples for the urban population was 64.1 pg mg(−1) (17.7–192.8 pg mg(−1)), for the rural population 40.3 pg mg(−1) (13.1–72.8 pg mg(−1)) and for the children 37.9 pg mg(−1) (13.1–72.8 pg mg(−1)). Significant statistical differences (p = 0.021) were observed though between urban and rural population only when negative samples were replaced with LOD/2 values.

CONCLUSION

The proposed method was successfully applied for the determination of BPA in hair for the estimation of the population burden to BPA.

Concentrations of phthalates and bisphenol A in Norwegian foods and beverages and estimated dietary exposure in adults

Phthalates and bisphenol A (BPA) are ubiquitous in our environment. These chemicals have been characterized as endocrine disruptors that can cause functional impairment of development and reproduction. Processed and packaged foods are among the major sources of human exposure to these chemicals. No previous report showing the levels of these chemicals in food items purchased in Norway is available. The aim of the present study was to determine the concentration of ten different phthalates and BPA in foods and beverages purchased on the Norwegian market and estimate the daily dietary exposure in the Norwegian adult population. Commonly consumed foods and beverages in Norway were purchased in a grocery store and analysed using gas- and liquid chromatography coupled with mass spectrometry. Daily dietary exposures to these chemicals in the Norwegian adult population were estimated using the latest National dietary survey, Norkost 3 (2010-2011). This study showed that phthalates and BPA are found in all foods and beverages that are common to consume in Norway. The detection frequency of phthalates in the food items varied from 11% for dicyclohexyl phthalate (DCHP) to 84% for di-iso-nonyl phthalate (DiNP), one of the substitutes for bis(2-ethylhexyl) phthalate (DEHP). BPA was found in 54% of the food items analysed. Among the different phthalates, the highest concentrations were found for DEHP and DiNP in the food items. Estimated dietary exposures were also equally high and dominated by DEHP and DiNP (400-500 ng/kg body weight (bw)/day), followed by di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di-n-octyl phthalate (DnOP) and di-iso-decyl phthalate (DiDP) (30-40 ng/kg bw/day). Dimethyl phthalate (DMP), diethylphthalate (DEP) and DCHP had the lowest concentrations and the exposures were around 10-20 ng/kg bw/day. Estimated dietary exposure to BPA was 5 ng/kg bw/day. In general, levels of phthalates and BPA in foods and beverages from the Norwegian market are comparable to other countries worldwide. Grain and meat products were the major contributors of exposure to these chemicals in the Norwegian adult population. The estimated dietary exposures to these chemicals were considerably lower than their respective tolerable daily intake (TDI) values established by the European Food Safety Authority (EFSA).

Molecularly imprinted solid-phase extraction for selective extraction of bisphenol analogues in beverages and canned food

This study aimed to develop a selective analytical method for the simultaneous determination of seven bisphenol analogues in beverage and canned food samples by using a new molecularly imprinted polymer (MIP) as a sorbent for solid-phase extraction (SPE). Liquid chromatography coupled to triple-quadruple tandem mass spectrometry (LC-MS/MS) was used to identify and quantify the target analytes. The MIP-SPE method exhibited a higher level of selectivity and purification than the traditional SPE method. The developed procedures were further validated in terms of accuracy, precision, and sensitivity. The obtained recoveries varied from 50% to 103% at three fortification levels and yielded a relative standard deviation (RSD, %) of less than 15% for all of the analytes. The limits of quantification (LOQ) for the seven analytes varied from 0.002 to 0.15 ng/mL for beverage samples and from 0.03 to 1.5 ng/g for canned food samples. This method was used to analyze real samples that were collected from a supermarket in Beijing. Overall, the results revealed that bisphenol A and bisphenol F were the most frequently detected bisphenols in the beverage and canned food samples and that their concentrations were closely associated with the type of packaging material. This study provides an alternative method of traditional SPE extraction for screening bisphenol analogues in food matrices.

Bisphenol A in domestic and imported canned foods in Japan

Bisphenol A (BPA) concentrations were surveyed in 100 domestic and 60 imported canned foods purchased from the Japanese market in 2011-12. BPA was extracted from the canned foods, derivatised by ethylation and analysed using GC-MS. In the domestic canned foods, the maximum and average BPA concentrations were 30 and 3.4 ng g(-1), respectively, while in the imported canned foods they were 390 and 57 ng g(-1), respectively. The BPA level in the domestic canned foods was significantly lower than that in the imported canned foods. Based on these results, the intakes of BPA from the domestic and imported canned foods in Japan were estimated as 644 ng person(-1) day(-1). The Japanese BPA intake was the second lowest following New Zealand, although imported canned foods increased. It was sufficiently lower than the tolerable daily intake of EFSA and the USEPA. The drastic reduction of BPA in the domestic canned foods should be due to the 'BPA reduced cans' that Japanese can manufacturers had developed in the late 1990s and became widely used in Japan.

TDS exposure project: relevance of the total diet study approach for different groups of substances

A method to validate the relevance of the Total Diet Study (TDS) approach for different types of substances is described. As a first step, a list of >2800 chemicals classified into eight main groups of relevance for food safety (natural components, environmental contaminants, substances intentionally added to foods, residues, naturally occurring contaminants, process contaminants, contaminants from packaging and food contact materials, other substances) has been established. The appropriateness of the TDS approach for the different substance groups has then been considered with regard to the three essential principles of a TDS: representativeness of the whole diet, pooling of foods and food analyzed as consumed. Four criteria were considered for that purpose (i) the substance has to be present in a significant part of the diet or predominantly present in specific food groups, (ii) a robust analytical method has to be available to determine it in potential contributors to the dietary exposure of the population, and (iii) the dilution impact of pooling and (iv) the impact of everyday food preparation methods on the concentration of the substance are assessed. For most of the substances the TDS approach appeared to be relevant and any precautions to be taken are outlined.

Urinary bisphenol A levels in young men: association with reproductive hormones and semen quality

BACKGROUND

Few human studies have examined bisphenol A (BPA) exposure in relation to semen quality and reproductive hormones in men, and results are divergent.

OBJECTIVES

We examined associations between urinary BPA concentration and reproductive hormones, as well as semen quality, in young men from the general population.

METHODS

Our study population consisted of 308 young men from the general population. Urinary BPA concentration was measured by isotope dilution TurboFlow-liquid chromatography-tandem mass spectrometry. We used multiple linear regression analysis to estimate associations between BPA concentration and reproductive hormones and semen quality, adjusting for confounding factors.

RESULTS

We found that 98% of the men had detectable urinary levels of BPA. Median (5th-95th percentiles) BPA concentration was 3.25 ng/mL (0.59-14.89 ng/mL). Men with BPA concentrations above the lowest quartile had higher concentrations of serum testosterone, luteinizing hormone (LH), estradiol, and free testosterone compared with the lowest quartile (p trend ≤ 0.02). Men in the highest quartile of BPA excretion had on average 18% higher total testosterone (95% CI: 8, 28%), 22% higher LH (95% CI: 6, 39%), and 13% higher estradiol (95% CI: 4, 24%) compared with lowest quartile. Men in the highest quartile of BPA also had significantly lower percentage progressive motile spermatozoa compared with men in the lowest quartile (-6.7 percentage points, 95% CI: -11.76, -1.63). BPA was not associated with other semen parameters. Adjusting for dietary patterns did not influence the results.

CONCLUSIONS

The pattern of associations between BPA and reproductive hormones could indicate an antiandrogenic or antiestrogenic effect, or both, of BPA on the hypothalamic-pituitary-gonadal hormone feedback system, possibly through a competitive inhibition at the receptor level. However, additional research is needed to confirm our findings and to further test the suggested potential mechanisms.