Dietary exposure assessment of pregnant women to bisphenol-A from cans and microwave containers in Southern Spain

Development and evaluation of a novel dietary bisphenol A (BPA) exposure risk tool

BACKGROUND

Exposure to endocrine disrupting chemicals such as bisphenol A (BPA) is primarily from the diet through canned foods. Characterizing dietary exposures can be conducted through biomonitoring and dietary surveys; however, these methods can be time-consuming and challenging to implement.

METHODS

We developed a novel dietary exposure risk questionnaire to evaluate BPA exposure and compared these results to 24-hr dietary recall data from participants (n = 404) of the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) study, a dietary clinical trial, to validate questionnaire responses. High BPA exposure foods were identified from the dietary recalls and used to estimate BPA exposure. Linear regression models estimated the association between exposure to BPA and questionnaire responses. A composite risk score was developed to summarize questionnaire responses.

RESULTS

In questionnaire data, 65% of participants ate canned food every week. A composite exposure score validated that the dietary exposure risk questionnaire captured increasing BPA exposure. In the linear regression models, utilizing questionnaire responses vs. 24-hr dietary recall data, participants eating canned foods 1-2 times/week (vs. never) consumed 0.78 more servings (p < 0.001) of high BPA exposure foods, and those eating canned foods 3+ times/week (vs. never) consumed 0.89 more servings (p = 0.013) of high BPA exposure foods. Participants eating 3+ packaged items/day (vs. never) consumed 62.65 more total grams of high BPA exposure food (p = 0.036).

CONCLUSIONS

Dietary exposure risk questionnaires may provide an efficient alternative approach to 24-hour dietary recalls to quantify dietary BPA exposure with low participant burden.

TRIAL REGISTRATION

The trial was prospectively registered at clinicaltrials.gov as NCT01826591 on April 8, 2013.

Phthalate and bisphenol a exposures during pregnancy: Findings from the National Children's Study

Maternal exposure to phthalates and bisphenol A (BPA) during pregnancy can result in many adverse offspring health outcomes. Exposure to phthalates and BPA can vary depending on consumption of certain foods, some of which may vary by race/ethnicity. This study relates urine phthalate and BPA concentrations to sociodemographic and diet data. Concentrations of bisphenol A (BPA) and 11 phthalate metabolites were measured from spot urine at the third trimester visit of a sample of 485 pregnant women from the National Children's Study Vanguard Study Pilot data from seven U.S. cities. At the same time, food frequency questionnaires (FFQ) using the Diet*Calc software were obtained from 313 (65%) participants to assess dietary behavior. Overall, phthalate metabolites were highest among Hispanic women, particularly mBP, miBP, and mECPP, and these disparities were not explained by diet. Participants who did not attend college had higher concentrations of mBP, mBzP, mEP, and miBP, and lower mCOP. These disparities were also not explained by diet. The causes for these disparities should be further studied to reduce potential negative health outcomes associated with phthalate exposure for children of Hispanic or non-college educated women.

Human health risk assessment of bisphenol A (BPA) through meat products

Meat and meat products are often consumed in our daily diet, providing essential nutrients. Contamination by chemical hazards, including bisphenol A (BPA) in meat products, is a concern and is continuously monitored. BPA is well-known for its endocrine-disrupting properties, which may cause potential toxicological effects on reproductive, nervous, and immune systems. Dietary consumption is the main route of BPA exposure, and meat products are a major contributor. BPA exposure from meat consumption is the focus of this review. This review found that BPA has been widely detected in canned and non-canned meat products. BPA in canned meat is assumed to be predominantly from migration from can coatings. Relatively low levels are observed in non-canned products, and the source of contamination in these products has yet to be definitively identified. A recent European Food Safety Authority (EFSA) draft opinion has proposed to lower the tolerable daily intake of BPA from 4 μg kg body weight (bw)^-1 day^-1 to 0.04 ng kg body weight (bw)^-1 day^-1, therefore potential health risks need to be addressed. This review has investigated potential contamination at the farm, industrial processes, and retail levels. Data gaps in the literature are also identified to improve future food safety in the meat industry. Also, a unified risk assessment strategy has been proposed. Further understanding of BPA migration in meat products is needed as a part of the exposure assessment to reduce potential risk, and more data on the dose-response relationship will help comprehend potential adverse health effects of BPA on humans. This research will inform the public, meat producers and processing industry, and policymakers on potential exposure to BPA and risk reduction measures, thus, ensuring food safety.

Human biomonitoring of bisphenol A along pregnancy: An exposure reconstruction of the EXHES-Spain cohort

This study was aimed at reconstructing the exposure to bisphenol (BPA) of 60 pregnant women from the EXHES-Spain cohort. A biomonitoring study was conducted by determining BPA levels in urine samples over the three trimesters of pregnancy. Moreover, the correlations between BPA levels and the role of different potential exposure sources, with special emphasis on the dietary intake, were also studied. Urine samples were subjected to dispersive liquid-liquid microextraction and the subsequent analysis via gas chromatography-mass spectrometry. BPA was detected in 76% of the urine samples. A significant decrease of urinary BPA levels was observed along pregnancy, as mean concentrations of creatinine-adjusted BPA were 4.64, 4.84 and 2.51 μg/g in the first, second and third trimester, respectively. This decrease was essentially associated with changes in the dietary habits of the pregnant women, including a lower intake of canned food and drinks. However, the potential role of other pregnancy-related biochemical or physiological factors should not be disregarded. Very interestingly, significant differences in urine BPA levels were found according to the fruit consumption pattern, as women who ate more citrus fruits showed lower BPA concentrations in urine. The reconstructed exposure to BPA was estimated in 0.072, 0.069 and 0.038 μg BPA/kg of body weight/day in the first, second and third trimesters, respectively. These values are far below the temporary tolerable daily intake (t-TDI) established by the EFSA.

Bisphenol A and Metabolites in Meat and Meat Products: Occurrence, Toxicity, and Recent Development in Analytical Methods

Bisphenol A (BPA) is a commonly used compound in many industries and has versatile applications in polycarbonate plastics and epoxy resins production. BPA is classified as endocrine-disrupting chemical which can hamper fetal development during pregnancy and may have long term negative health outcomes in humans. Dietary sources, main route of BPA exposure, can be contaminated by the migration of BPA into food during processing. The global regulatory framework for using this compound in food contact materials is currently not harmonized. This review aims to outline, survey, and critically evaluate BPA contamination in meat products, including level of BPA and/or metabolites present, exposure route, and recent advancements in the analytical procedures of these compounds from meat and meat products. The contribution of meat and meat products to the total dietary exposure of BPA ranges between 10 and 50% depending on the country and exposure scenario considered. From can lining materials of meat products, BPA migrates towards the solid phase resulting higher BPA concentration in solid phase than the liquid phase of the same can. The analytical procedure is comprised of meat sample pre-treatment, followed by cleaning with solid phase extraction (SPE), and chromatographic analysis. Considering several potential sources of BPA in industrial and home culinary practices, BPA can also accumulate in non-canned or raw meat products. Very few scientific studies have been conducted to identify the amount in raw meat products. Similarly, analysis of metabolites and identification of the origin of BPA contamination in meat products is still a challenge to overcome.

Use of Plastics with Hot Food among Saudi Pregnant Women Is Associated with Increased Concentrations of A1C, Thyroid-Stimulating Hormone, and Homocysteine and Decreased Concentrations of Vitamins and Minerals

Data regarding association between the use of plastics with hot food and levels of vitamins and minerals, and other biochemical parameters are lacking. Cross-sectional data for 740 healthy pregnant Saudi women were collected from 21 health care centres and 2 hospitals from Madinah, Saudi Arabia. Detailed data regarding the frequency of plastic use with hot food were collected, and laboratory analyses of thyroid-stimulating hormone (TSH), homocysteine (HCY), glycated A1C (A1C), and selected vitamins and minerals were also done. Daily use of plastics with hot food was frequently reported among young mothers (p = 0.002). Plastic use with hot food on a daily basis was positively associated with TSH, HCY, and A1C, while it was negatively associated with concentrations of vitamin E, zinc, and selenium. Future research should address the complex hormonal and metabolic abnormalities that are linked to the release of certain components associated with the use of plastics with hot food. Interventions are urgently needed to eliminate the use of plastics with hot food to prevent health complications that may result from the long-term use of these materials.

Fetal-Maternal Exposure to Endocrine Disruptors: Correlation with Diet Intake and Pregnancy Outcomes

Endocrine-disrupting chemicals (EDCs) are exogenous substances able to mimic or to interfere with the endocrine system, thus altering key biological processes such as organ development, reproduction, immunity, metabolism and behavior. High concentrations of EDCs are found in several everyday products including plastic bottles and food containers and they could be easily absorbed by dietary intake. In recent years, considerable interest has been raised regarding the biological effects of EDCs, particularly Bisphenol A (BPA) and phthalates, on human pregnancy and fetal development. Several evidence obtained on in vitro and animal models as well as by epidemiologic and population studies strongly indicated that endocrine disruptors could negatively impact fetal and placental health by interfering with the embryonic developing epigenome, thus establishing disease paths into adulthood. Moreover, EDCs could cause and/or contribute to the onset of severe gestational conditions as Preeclampsia (PE), Fetal Growth Restriction (FGR) and gestational diabetes in pregnancy, as well as obesity, diabetes and cardiovascular complications in reproductive age. Therefore, despite contrasting data being present in the literature, endocrine disruptors must be considered as a therapeutic target. Future actions aimed at reducing or eliminating EDC exposure during the perinatal period are mandatory to guarantee pregnancy success and preserve fetal and adult health.

Dietary Predictors of Phthalate and Bisphenol Exposures in Pregnant Women

Endocrine disrupting chemicals (EDCs) can disrupt fetal developmental processes during pregnancy, leading to long-term adverse outcomes in humans. A major source of exposure to EDCs, such as phthalates and bisphenols, is the food supply, primarily due to contamination from processing and packaging. Therefore, this review aimed to 1) review food-monitoring sources of phthalates and bisphenols, and 2) evaluate methodologies and provide future directions needed to establish EDC-limiting dietary recommendations in pregnancy. Using PubMed, 10 peer-reviewed studies were found on dietary predictors of EDC exposure in pregnancy, and all were selected for review. Use of plastic containers in pregnancy was associated with higher urinary phthalate metabolites, whereas canned food consumption was associated with higher urinary bisphenol A (BPA) concentrations. Foods and dietary patterns associated with healthier food choices (e.g., organic/grown/raised/caught foods, folic acid supplements, vegetarianism) were generally associated with lower urinary phthalate metabolite and BPA concentrations. Despite the many food-monitoring studies reporting high BPA and phthalate concentrations in various foods, the designs of most studies described here were not sufficiently robust to consistently detect associations of specific foods/food groups with phthalates and BPA. Given the limitations of currently available research, future studies should incorporate more valid questionnaires to accurately assess dietary EDC exposure, strive for concurrent diet and exposure assessment, and assess whether geographical and cultural differences modify associations of diet with gestational EDC exposures. Such progress will be critical for developing dietary recommendations that ensure the safety and health of pregnant women.

Quantification of eight bisphenol analogues in blood and urine samples of workers in a hazardous waste incinerator

Bisphenol A (BPA) has been widely used in the manufacture of polycarbonate plastic and epoxy resins. In recent years, producers have started replacing BPA by other chemical analogues, such as bisphenol -S (BPS) and -F (BPF), all of them under the label "BPA-free". However, despite bisphenol (BP) analogues have a very similar structure, their endocrine-disrupting properties could differ from those of BPA. Unfortunately, information regarding human exposure to BP analogues is very limited, not only as single substances, but also as chemical mixtures. The aim of this study was to determine the levels of 8 BP analogues (A, S, F, B, AF, Z, E, and AP) in biological samples from a controlled cohort of workers in a hazardous waste incinerator (HWI) located in Constantí (Catalonia, Spain). Firstly, a chemical method to analyze a mixture of those 8 analogues in total blood and urine was optimized, being samples quantified by means of gas chromatography coupled to mass spectrometry (GC-MS). Furthermore, a biomonitoring study was performed by collecting samples of total blood and urine of 29 people working in the HWI. Among the 8 BP analogues assessed, BPA presented the highest levels in both biological samples, with mean total (free + conjugated) BPA concentrations of 0.58 and 0.86 μg/L in blood and urine, respectively. Free vs. total BPA levels presented a mean percentage of 79% in blood and 19% in urine. Beyond BPA, traces of BPB were also found in a single sample of blood. Furthermore, none of the remaining BP analogues was detected in blood or urine. Despite BPA has been regulated, it is still very present in the environment, being human exposure to this chemical still an issue of concern for the public health.

Urinary bisphenol A (BPA) concentrations and exposure predictors among pregnant women in the Laizhou Wan Birth Cohort (LWBC), China

Although BPA use is widespread and often detectable in humans, little is known about its exposure levels and potential exposure predictors in pregnant women in China. We investigated the BPA exposure levels in pregnant women and its health implications and potential exposure predictors. Urinary BPA levels were measured for 506 pregnant women in northern China. Hazard quotients (HQs) based on estimated daily intakes (EDIs) were conducted. Sociodemographic characteristics and food consumption during pregnancy were collected and seasons of sample collection were recorded. The detection rate of urinary BPA was 86.6% and the median concentrations were 0.48 μg/L (1.05 μg/g creatinine). The EDI (median = 0.008 μg/kg bw/day) was much lower than the recommended tolerable daily doses and the HQ (median = 0.002) much lower than 1. The urine collected in summer had significantly higher BPA levels than that collected in other seasons (β = 0.225; 95% CI - 0.008, 0.458; p = 0.03). Women "always consuming shellfish" had significantly higher BPA levels than those "seldom consuming shellfish" (β = 0.341; 95% CI 0.022, 0.66; p = 0.04). The study found a wide exposure to BPA among pregnant women in this region, which might be associated with seasonal variation and shellfish consumption. Although the HQs suggested no obvious risk, further attention to the comprehensive exposure and potential determinants should be paid in view of its endocrine-disrupting potential.

Estimates of dietary exposure of Spanish population to packaging contaminants from cereal based foods contained in plastic materials

Food packaging may be a potential source of contamination, through the migration of chemicals from the packaging into the food, thus food consumption is an important route of human exposure to packaging contaminants. In the present study an approach to estimate the exposure to different chemicals transferred from food packaging was designed. As a first step a GC-MS screening was conducted to identify potential contaminants in the materials. Secondly, different chemicals previously identified in the packaging materials were selected for exposure assessment. The proposed methodology was applied to cereal based foods packed with plastic packaging. A variety of chemicals including e.g. acetyl tributyl citrate (ATBC), bis (2-ethylhexyl) adipate (DEHA) and diethyl phthalate (DEP) among others were identified and analyzed in the foodstuffs. For this purpose a LC-MS/MS method was developed. The selected foodstuffs were pooled into three groups according to the population age (12-35 months, 3-9 years and 10-17 years) and based on the Spanish consumption data (Enalia). In general, ATBC mean exposure was higher than that of phthalates and DEHA for the three groups considered, with mean dietary exposure values ranging from 1.01 μg/kg bw/day (pool 12-35 months) to 2.01 μg/kg bw/day (pool 3-9 years).

Distribution, variability, and predictors of urinary bisphenol A levels in 50 North Carolina adults over a six-week monitoring period

Bisphenol A (BPA) is commonly manufactured to make polycarbonate plastics and epoxy resins for use in consumer products and packaged goods. BPA has been found in several different types of environmental media (e.g., food, dust, and air). Many cross-sectional studies have frequently detected BPA concentrations in adult urine samples. However, limited data are available on the temporal variability and important predictors of urinary BPA concentrations in adults. In this work, the major objectives were to: 1) quantify BPA levels in duplicate-diet solid food, drinking water, hard floor surface wipe, and urine samples (first-morning void [FMV], bedtime, and 24-h) collected from adults over a six-week monitoring period; 2) determine the temporal variability of urinary BPA levels using concentration, specific gravity (SG) adjusted, creatinine (CR) adjusted, and excretion rate values, and; 3) examine associations between available study factors and urinary BPA concentrations. In 2009-2011, a convenience sample of 50 adults was recruited from residential settings in North Carolina. The participants completed diaries and collected samples during weeks 1, 2, and/or 6 of a six-week monitoring period. BPA was detected in 38%, 4%, and 99% of the solid food (n=775), drinking water (n=50), and surface wipe samples (n=138), respectively. Total BPA (free plus conjugated) was detected in 98% of the 2477 urine samples. Median urinary BPA levels were 2.07ng/mL, 2.20ng/mL-SG, 2.29ng/mg, and 2.31ng/min for concentration, SG-adjusted, CR-adjusted, and excretion rate values, respectively. The intraclass correlation coefficient (ICC) estimates for BPA showed poor reproducibility (≤0.35) for all urine sample types and methods over a day, week, and six weeks. CR-adjusted bedtime voids collected over six-weeks required the fewest, realistic number of samples (n=11) to obtain a reliable biomarker estimate (ICC=0.80). Results of linear mixed-effects models showed that sex, race, season, and CR-level were all significant predictors (p<0.05) of the adults' urinary BPA concentrations. BPA levels in the solid food and surface wipe samples did not contribute significantly to the participants' urinary BPA concentrations. However, a significant positive relationship was observed between solid food intake and urine-based estimates of BPA dose, when aggregated over 24-h periods. Ingestion of BPA via solid food explained only about 20% of the total dose (at the median of the dose distribution), suggesting that these adults were likely exposed to other major unknown (non-dietary) sources of BPA in their everyday environments.

Effects of perinatal exposure to bisphenol A on the intraprostatic levels of aromatase and 5α-reductase isozymes in juvenile rats

The impact of bisphenol A (BPA) on the prostate gland has taken center stage, with a special focus placed on understanding how BPA affects prostate physiopathology. In this study, we evaluated the ability of lower doses of BPA to induce alterations in 5α-R isozymes and aromatase, in the prostate of juvenile rats exposed during developmental stage. Gestating Wistar rats were treated s.c with either vehicle or BPA (2.4 and 10 μg/kg b.w./day) from gestational day 12 to parturition. Then, male pups were s.c treated from postnatal day 1 through day 21, when they were euthanized and qRT-PCR, western blot and hormone levels determination were performed. We found that BPA at dose of 2.4 and 10 μg/kg b.w./day significantly decreased the mRNA and protein levels of 5α-R2. However, neither 5α-R1 nor 5α-R3 was affected by this exposure. BPA at dose of 10 μg/kg b.w./day significantly increased the mRNA and protein levels of aromatase. BPA also decreased plasma levels of both testosterone and dihydrotestosterone and increased estradiol. These data lend support that low-dose BPA during fetal and neonatal prostate development interfere with in situ estrogen and androgen production in the prostate gland of juvenile rats through the enzymes aromatase and 5α-Reductase.

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.

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.

Salmon Muscle Adherence to Polymer Coatings and Determination of Antibiotic Residues by Reversed-Phase High-Performance Liquid Chromatography Coupled to Selected Reaction Monitoring Mass Spectrometry, Atomic Force Microscopy, and Fourier Transform Infrared Spectroscopy

The persistent adhesion of salmon muscle to food container walls after treatment with urea solution was observed. This work evaluated the diffusion of antibiotics from the salmon muscle to the polyethylene terephthalate (PET) coating protecting the electrolytic chromium coated steel (ECCS) plates. New aquaculture production systems employ antibiotics such as florfenicol, florfenicol amine, oxytetracycline, and erythromycin to control diseases. The introduction of antibiotics is a matter of concern regarding the effects on human health and biodiversity. It is important to determine their impact on the adhesion of postmortem salmon muscle to can walls and the surface and structural changes affecting the functionality of multilayers. This work characterized the changes occurring in the multilayer PET polymer and steel of containers by electron microscopy, 3D atomic force microscopy (3D-AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. A robust mass spectrometry methodology was employed to determine the presence of antibiotic residues. No evidence of antibiotics was observed on the protective coating in the range between 0.001 and 2.0 ng/mL; however, the presence of proteins, cholesterol, and alpha-carotene was detected. This in-depth profiling of the matrix-level elements is relevant for the use of adequate materials in the canning export industry.

Formaldehyde and heavy metal migration from rubber and metallic packaging/utensils in Korea

The aim of this study was to determine the non-intentionally added substances--formaldehyde and trace metals--at 4% acetic acid conditions in rubber and metallic packaging/utensils. The temperature effect on migration in rubber and metallic packaging/utensils was monitored at 60 °C and 100 °C under acidic (pH < 3) circumstances. The concentrations were: formaldehyde--23.1 μg kg⁻¹, lead--13.41 μg kg⁻¹, cadmium--0.15 μg kg⁻¹, total arsenic--2.02 μg kg⁻¹ and nickel--2.92 μg kg⁻¹ at 60 °C and formaldehyde--148.9 μg kg⁻¹, lead--17.04 μg kg⁻¹, cadmium--0.14 μg kg⁻¹, total arsenic--7.25 μg kg⁻¹ and nickel--8.7 μg kg⁻¹ at 100 °C. A significant difference was noticed in formaldehyde and total arsenic between both temperatures (p < 0.01), which was not present in other trace metals. In conclusion, formaldehyde and total arsenic were more sensitive with cooking temperature than the other metals.

Dietary predictors of urinary environmental biomarkers in young girls, BCERP, 2004-7

BACKGROUND

Exposures of children to phthalates, parabens, and bisphenol-A (BPA) are of concern because of their hormonal potential. These agents are found in a wide range of foods and packaging. We investigated whether intake of certain foods predict exposures to these chemicals in young girls.

METHODS

Among 1101 girls (6-8 years at enrollment) from the Breast Cancer and Environment Research Program (BCERP) study, we measured urinary exposure biomarkers for phthalates, parabens, and BPA and assessed dietary intake using 24-h recall 2-4 times. We examined the average daily servings of major and minor food groups categorized as 0 to <0.5, 0.5 to <1 and ≥ 1 servings per day. Items included dairy, eggs, fats, fish, fruit, single grains, meat, non-poultry meats, pasta, poultry and vegetables. Covariate-adjusted least squares geometric means and 95% confidence intervals of creatinine-corrected phthalate and phenol metabolite concentrations in urine were calculated in relation to food intake.

RESULTS

Grains, flour and dry mixes and total fish consumption were positively associated with BPA and the sum of four di-2-ethylhexylphthalate (DEHP) urinary metabolite concentrations. Non-fresh vegetables and poultry were both positively associated with BPA and paraben urinary concentrations. Fats, oils and poultry consumption were positively associated with BPA. Whole-fat dairy consumption was associated with ΣDEHP.

CONCLUSIONS

Some foods may contribute to child exposures to certain chemicals, and this may constitute modifiable means to reduce these environmental exposures.

Analysis of estrogens and estrogen mimics in edible matrices--a review

This review provides a brief survey of the biological effects of selected endocrine-disrupting compounds that are formed after internal exposure of organisms. Further, the present analytical methods available for the determination of these compounds in foodstuffs are critically evaluated. The attention is primarily devoted to the methods for sample pretreatment, which are the main source of errors and are usually the most time-consuming step of the whole analysis. This review is focused on selected natural and synthetic estrogens, estrogen conjugates, and chemical additives used in the plastic industry that can act as estrogen mimics.

Disconcordance in statistical models of bisphenol A and chronic disease outcomes in NHANES 2003-08

Background

Bisphenol A (BPA), a high production chemical commonly found in plastics, has drawn great attention from researchers due to the substance’s potential toxicity. Using data from three National Health and Nutrition Examination Survey (NHANES) cycles, we explored the consistency and robustness of BPA’s reported effects on coronary heart disease and diabetes.

Methods And Findings

We report the use of three different statistical models in the analysis of BPA: (1) logistic regression, (2) log-linear regression, and (3) dose-response logistic regression. In each variation, confounders were added in six blocks to account for demographics, urinary creatinine, source of BPA exposure, healthy behaviours, and phthalate exposure. Results were sensitive to the variations in functional form of our statistical models, but no single model yielded consistent results across NHANES cycles. Reported ORs were also found to be sensitive to inclusion/exclusion criteria. Further, observed effects, which were most pronounced in NHANES 2003-04, could not be explained away by confounding.

Conclusions

Limitations in the NHANES data and a poor understanding of the mode of action of BPA have made it difficult to develop informative statistical models. Given the sensitivity of effect estimates to functional form, researchers should report results using multiple specifications with different assumptions about BPA measurement, thus allowing for the identification of potential discrepancies in the data.

Determination of five bisphenols in commercial milk samples by liquid chromatography coupled to fluorescence detection

The presence of five bisphenols, i.e., bisphenol F, bisphenol A, bisphenol B, bisphenol F diglycidyl ether, and bisphenol A diglycidyl ether, was monitored in commercial milk packed in plastic bottles marketed in Italy. The new validated method includes a solid-phase extraction procedure followed by liquid chromatography with fluorescence detection. All positive results were confirmed by liquid chromatography-tandem mass spectrometry analysis. The limits of detection and quantification and the recovery percentages indicated that the method is suitable for detecting bisphenols in milk at concentrations far below the legal limits. Of 68 commercial milk samples analyzed, no bisphenol was found in 27 samples (39.7%), and 41 samples (60.3%) contained one or more bisphenols. The bisphenol most frequently found was bisphenol F (36 samples, 52.9%) followed by bisphenol A (20 samples, 29.4%) and bisphenol B (6 samples, 8.8%). Taking into consideration the limits of detection, no sample contained either bisphenol F diglycidyl ether or bisphenol A diglycidyl ether.

Dietary and sociodemographic determinants of bisphenol A urine concentrations in pregnant women and children

Bisphenol A (BPA) exposure during early life may have endocrine-disrupting effects, but the dietary and sociodemographic predictors of BPA exposure during pregnancy and childhood remain unclear. Our aim was to evaluate the correlations between, and sociodemographic and dietary predictors of, serial urinary BPA concentrations measured during pregnancy and childhood in a Spanish birth cohort study. BPA was measured in two spot urine samples collected from 479 women during the first and third trimester of pregnancy and in one urine sample from their 4-year old children (n=130). Average dietary intakes were reported in food frequency questionnaires during the first and third pregnancy trimester and at age 4years. Multivariate mixed models and linear regression models were used to estimate associations between sociodemographic and dietary factors and BPA concentrations. A small, but statistically significant correlation was found between serial maternal BPA concentrations measured during pregnancy (r=0.17). Pregnant women who were younger, less-educated, smoked, and who were exposed to second-hand tobacco smoke (SHS) had higher BPA concentrations than others. BPA concentrations were also higher in children exposed to SHS. High consumption of canned fish during pregnancy was associated with 21% [GM ratio=1.21; 95%CI 1.02, 1.44] and 25% [GM ratio=1.25; 95%CI 1.05, 1.49] higher urinary BPA concentrations in the first and third pregnancy trimester, respectively, compared to the lowest consumption group. This study suggests that canned fish may be a major source of BPA during pregnancy in Spain, a country of high canned fish consumption. Further evaluation of specific BPA exposure sources in the sociodemographic group of younger women who smoke, are exposed to SHS, and have a low educational level is needed. Studies identifying sources of exposure would benefit from repeat BPA measurements and questionnaires specifically focused on dietary and packaging sources.

A review of dietary and non-dietary exposure to bisphenol-A

Due to the large number of applications of bisphenol-A (BPA), the human exposure routes are multiple. We aimed to review shortly the food and non-food sources of BPA, and to evaluate their contribution to the human exposure. Food sources discussed here include epoxy resins, polycarbonate and other applications, such as paperboard and polyvinylchloride materials. Among the non-food sources, exposures through dust, thermal paper, dental materials, and medical devices were summarized. Based on the available data for these exposure sources, it was concluded that the exposure to BPA from non-food sources is generally lower than that from exposure from food by at least one order of magnitude for most studied subgroups. The use of urinary concentrations from biomonitoring studies was evaluated and the back-calculation of BPA intake seems reliable for the overall exposure assessment. In general, the total exposure to BPA is several orders of magnitude lower than the current tolerable daily intake of 50 μg/kg bw/day. Finally, the paper concludes with some critical remarks and recommendations on future human exposure studies to BPA.

Occurrence of bisphenol A in indoor dust from two locations in the eastern United States and implications for human exposures

Bisphenol A (BPA) is used in the production of polycarbonate plastics and epoxy resins, which are used in many consumer products. Sources of human exposures to BPA include packaged and canned food products, indoor air, and dust ingestion. Information on the relative contributions of the pathways to BPA exposures is limited. In this study, we measured concentrations BPA in indoor dust collected from two locations in the Eastern United States and evaluated the contribution of dust to total BPA exposures. BPA was found in 95% of the dust samples analyzed (n = 56) at concentrations ranging from <0.5 to 10,200 ng/g (mean 843; median 422). The median values for BPA intake by way of the ingestion of dust by adults and toddlers were calculated to be 0.35 and 5.63 ng/kg body weight/day. These estimated exposure doses of BPA through dust ingestion are of the same order of magnitude as the recently reported low concentrations that induced health effects in laboratory animal studies. The contribution of dust to total human BPA intake was estimated to be <1%, however, suggesting that dietary intake is the predominant source of exposures in humans.

Concentrations of bisphenol A in the composite food samples from the 2008 Canadian total diet study in Quebec City and dietary intake estimates

A total of 154 food composite samples from the 2008 total diet study in Quebec City were analysed for bisphenol A (BPA), and BPA was detected in less than half (36%, or 55 samples) of the samples tested. High concentrations of BPA were found mostly in the composite samples containing canned foods, with the highest BPA level being observed in canned fish (106 ng g(-1)), followed by canned corn (83.7 ng g(-1)), canned soups (22.2-44.4 ng g(-1)), canned baked beans (23.5 ng g(-1)), canned peas (16.8 ng g(-1)), canned evaporated milk (15.3 ng g(-1)), and canned luncheon meats (10.5 ng g(-1)). BPA levels in baby food composite samples were low, with 2.75 ng g(-1) in canned liquid infant formula, and 0.84-2.46 ng g(-1) in jarred baby foods. BPA was also detected in some foods that are not canned or in jars, such as yeast (8.52 ng g(-1)), baking powder (0.64 ng g(-1)), some cheeses (0.68-2.24 ng g(-1)), breads and some cereals (0.40-1.73 ng g(-1)), and fast foods (1.1-10.9 ng g(-1)). Dietary intakes of BPA were low for all age-sex groups, with 0.17-0.33 µg kg(-1) body weight day(-1) for infants, 0.082-0.23 µg kg(-1) body weight day(-1) for children aged from 1 to 19 years, and 0.052-0.081 µg kg(-1) body weight day(-1) for adults, well below the established regulatory limits. BPA intakes from 19 of the 55 samples account for more than 95% of the total dietary intakes, and most of the 19 samples were either canned or in jars. Intakes of BPA from non-canned foods are low.

Daily intake of bisphenol A and potential sources of exposure: 2005-2006 National Health and Nutrition Examination Survey

Nationally representative data on urinary levels of bisphenol A (BPA) and its metabolites in the United States from the 2005-2006 National Health and Nutrition Examination Survey (NHANES) were used to estimate daily BPA intakes. In addition, NHANES data on potential sources of BPA exposure and personal characteristics were explored for their association with urinary BPA levels. On the basis of 2005-2006 NHANES urinary BPA data and assumptions described in this paper, median daily intake for the overall population is approximately 34 ng/kg-day. Median daily BPA intakes for men are statistically significantly higher than for women; there is a significant decrease in daily BPA intake with increasing age. Gender- and age-specific median intakes differ from the overall population by less than a factor of 2. Although estimates of daily BPA intake have decreased compared with those from the 2003-2004 NHANES, it is premature to draw conclusions regarding trends at this time, as there is no indication that BPA use declined from 2003 to 2006. On the basis of an assessment of urinary BPA and questionnaire data from the 2005-2006 NHANES, consumption of soda, school lunches, and meals prepared outside the home--but not bottled water or canned tuna--was statistically significantly associated with higher urinary BPA.

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

Bisphenol A (BPA), a contaminant which may be present in the coating of cans, was determined in 45 canned beverages and 21 canned food items from the Belgian market. Beverages had an average BPA concentration of 1.0 ng/ml, while canned foods had a higher average concentration of 40.3 ng/g. The amount of BPA present in food items was dependent on the type of can and sterilisation conditions rather than the type of food. For example, BPA was not detected in non-canned beverages (<0.02 ng/ml), while non-canned food items had a very low average concentration of 0.46 ng/g. Using detailed information from the Belgian food consumption survey, the BPA intake of adults through canned foods and beverages was estimated to be 1.05 µg/day or 0.015 µg/kg body weight/day (assuming an average adult weight of 70 kg). Intake assessments, based on urinary metabolite concentrations from the literature, resulted in slightly higher BPA intakes (range 0.028-0.059 µg/kg body weight/day). This suggests that sources other than canned foods and beverages contribute to BPA exposure in humans.

Assessment of bisphenol A exposure in Korean pregnant women by physiologically based pharmacokinetic modeling

The objective of this study was to predict the exposure to bisphenol A (BPA) after oral intake in human blood and tissues using physiologically based pharmacokinetic (PBPK) modeling. A refined PBPK model was developed taking into account of glucuronidation, biliary excretion, and slow absorption of BPA in order to describe the second peak of BPA observed following oral intake. This developed model adequately described the second peak and BPA concentrations in blood and various tissues in rats after oral administration. A prospective validation study in rats additionally supported the proposed model. For extrapolation to humans, a daily oral BPA dose of 0.237 mg/70 kg/d or 0.0034 mg/kg/d was predicted to achieve an average steady-state blood concentration of 0.0055 ng/ml (median blood BPA concentration in Korean pregnant women). This dose was lower than the reference dose (RfD, 0.016 mg/kg/d) and the tolerable daily intake established by the European Commission (10 μg/kg/d). Data indicate that enterohepatic recirculation may be toxicologically important as this pathway may increase exposure and terminal half-life of BPA in humans.

Bisphenol A levels in blood depend on age and exposure

We present two approaches to estimate blood concentrations of Bisphenol A (BPA). Simple kinetic principles were applied to calculate steady state plasma concentrations. A physiologically based model was used to simulate the blood concentration time profile in several age groups exploring the influence of not yet fully developed metabolic capacity on the blood concentrations in the newborn. Both approaches gave concordant results and are in excellent agreement with experimental results [Völkel, W., Colnot, T., Csanady, G.A., Filser, J.G., Dekant, W., 2002. Metabolism and kinetics of bisphenol A in humans at low doses following oral administration. Chem. Res. Toxicol. 15, 1281-1287]. The predictions also agree with published results obtained with a different physiologically based model. According to model simulations, BPA is present in the blood of the normal population at concentrations several orders of magnitude lower than most measurements reported in the literature. At the same external exposure level, the newborn is predicted to have 3 times greater blood concentration than the adult. This is due to the not yet fully developed glucuronidation activity in the newborn, not fully compensated by the unimpaired sulfation pathway. For the highest measured external BPA exposure, the predicted blood concentrations of 2.6 pg/ml (steady state concentration) and 8.2 pg/ml (peak concentration) in the adult are lower than the in vitro concentrations at which inhibiting adiponectin release from human adipocytes and stimulation of beta-cell production and secretion were observed.

Risk assessment of bisphenol A migrated from canned foods in Korea

Exposure and risk assessment of bisphenol A (BPA) was conducted on consumption of canned foods in Korean adults. Sixty-one canned food items with different brands purchased from retail outlets in markets were analyzed for BPA concentration by high-performance liquid chromatography (HPLC) coupled with fluorescence detection. Limits of detection (LOD) were 3 microg/kg for solid and 2 microg/kg for liquid foods. BPA was detected from 7 groups of food items, such as tuna (n = 8), fish (n = 11), fruits (n = 9), vegetables (n = 12), meats (n = 13), coffee (n = 5), and tea (n = 3) in the range from not detected (ND) to 136.14 microg/kg. Mean concentrations of BPA were 3.1 microg/kg (ND-21.5 microg/kg) for vegetables, 8.3 microg/kg (ND-14.26) for tea, 8.6 microg/kg (ND-54.56 microg/kg) for fruits, 24.49 microg/kg (ND-98.30 microg/kg) for meats, 39.78 microg/kg (ND-125.25 microg/kg) for fish, 43.7 microg/kg (ND-116.88 microg/kg) for tuna, and 45.51 microg/kg (ND-136.14 microg/kg) for coffee, in the order of magnitude. Based on daily dietary intake of canned food items and concentrations of BPA, human exposure level to BPA was estimated to be 1.509 microg/kg body weight (bw)/d, well below the tolerable daily intake (TDI) or reference dose (RfD) of 50 microg/kg, bw/d set by the European Commission, U.S.EPA, and South Korea. Therefore, the potential risk for BPA contamination due to consumption of each canned food items was calculated to be (1.509 microg/kg bw/d)/(50 microg/kg bw/d) = 0.03, which is the hazard index [HI = exposure level/(RfD or TDI)]. Evidence indicates that the levels of BPA levels in canned foods are not likely to constitute a safety concern for consumers in Korea.