Total Bisphenol A Research Articles

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.

Serum unconjugated bisphenol A concentrations in women may adversely influence oocyte quality during in vitro fertilization

Bisphenol A (BPA) is an endocrine disruptor with estrogenic properties that can adversely affect meiotic spindle assemblies. Our data indicate that BPA exposure in female patients may interfere with oocyte quality during IVF, as suggested by the inverse association between serum unconjugated BPA concentration and normal fertilization.

Determination of free and total bisphenol A in urine of infants

Infants may be particularly sensitive regarding hormonally active compounds such as Bisphenol A (BPA), which is widely distributed and exhibits weak oestrogenic activity. Since only free (unconjugated) BPA exhibits endocrine activity, both free and total (after hydrolysis of conjugates) BPA were determined in urine samples of infants to support valid risk assessments. Free BPA was observed above the LOQ in only 3 of 91 (3%) samples from 47 infants. As total BPA was observed in only 38 (42%) urine samples, with concentrations between <LOQ and 17.85 μg/l, the median concentration was below the LOQ of 0.45 μg/l. Based on 0.225 μg/l (half of the LOQ), a margin of exposure 1400-fold below the tolerable daily intake (TDI) of 50 μg/kg bw was calculated. The highest concentration observed (17.85 μg/l) was 18-fold below the TDI. Infants who were fed using baby bottles show approximately 2-fold higher median levels of total BPA. Importantly, the higher levels of total BPA compared to free BPA demonstrate that conversion of BPA to biologically inactive conjugates such as glucuronides or sulphates, which is well known to efficiently occur in adults, also occurs in infants.

Lactational transfer of bisphenol A in Sprague–Dawley rats

Bisphenol A (BPA), an important industrial chemical to which humans are exposed on a daily basis, has long been associated with endocrine disruption in experimental animal models. Such exposures are of concern, particularly during fetal and early neonatal periods, because of greater vulnerability of developing organs to aberrant endocrine signaling. Although rarely reported, information about internal exposures to the receptor-active aglycone form of BPA during the perinatal period is essential to accurate assessment of potential risks. Lactating Sprague–Dawley dams were treated by daily gavage with 100 μg/kg bw d6-BPA starting at birth. Conjugated and aglycone forms of BPA were then measured by using LC/MS/MS in milk from lactating dams on PND 7 and in serum from dams and their pups on PND 10. All samples were collected 1 h after dosing, a time selected to produce nearly maximal levels. While aglycone BPA was detected in all dam serum and milk samples, none was detected in pup serum (<0.2 nM). Doses delivered to pups lactationally, estimated from milk concentrations and body weights, were 300-fold lower than the dose administered to the dams. Similarly, serum concentrations of total BPA in pups were 300-fold lower than those in their dams. Furthermore, plasma concentrations of total BPA in PND 10 rat pups were 500-fold lower than peak levels achieved following direct oral delivery of the same dose to the same age pups. These findings of significant dose attenuation for the active aglycone form of BPA, relative to that of the dam, suggest high potency for toxicological effects derived exclusively from lactational transfer. Alternatively, studies that include lactational exposure and report minimal effects from BPA should consider the possibility that inadequate internal exposures were achieved during the critical postnatal period.

Quantification of free and total bisphenol A and bisphenol B in human urine by dispersive liquid–liquid microextraction (DLLME) and heart-cutting multidimensional gas chromatography–mass spectrometry (MD–GC/MS)

A novel method combining dispersive liquid–liquid microextraction (DLLME) and heart-cutting multidimensional gas chromatography coupled to mass spectrometry was developed for the determination of free and total bisphenol A (BPA) and bisphenol B (BPB) in human urine samples. The DLLME procedure combines extraction, derivatization and concentration of the analytes into one step. Several important variables influencing the extraction efficiency and selectivity such as nature and volume of extractive and dispersive solvents as well as the amount of acetylating reagent were investigated. The temperature and time to hydrolyze BPA and BPB conjugates with a β-glucuronidase and sulfatase enzyme preparation were also studied. Under the optimized conditions good efficiency extraction (71–93%) and acceptable total DLLME yields (56–77%) were obtained for both analytes. Matrix-matched calibration curves were linear with correlation coefficients higher than 0.996 in the range level 0.1–5 μg/l, and the relative standard deviations (%RSD) were lower than 20% ( n = 6). The limits of detection were 0.03 and 0.05 μg/l for BPA and BPB, respectively. The applicability of the proposed method for determining urinary free and total BPA and BPB was assessed by analyzing the human urine of a group of 20 volunteers. Free BPA was detected in 45% of the sample whereas total BPA was detected in 85% of the samples at concentrations ranging between 0.39 and 4.99 μg/l. BPB was detected in conjugated form in two samples.

Body of Proof: Biomonitoring Data Reveal Widespread Bisphenol A Exposures

Vol. 118, No. 8 NewsOpen AccessBody of Proof: Biomonitoring Data Reveal Widespread Bisphenol A Exposures Kellyn S. Betts Kellyn S. Betts Search for more papers by this author Published:1 August 2010https://doi.org/10.1289/ehp.118-a353aCited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail A review of more than 80 biomonitoring studies from nine nations suggests exposure to bisphenol A (BPA) is ubiquitous in people throughout the world [EHP118(8):1055–1070; Vandenberg et al.]. Moreover, in samples of blood serum, median levels of unconjugated (biologically active) BPA were higher than levels predicted by toxicokinetic models that form the basis of U.S. regulations for the compound, reaching the range that has been shown to cause adverse effects in animals.More than 8 billion pounds of BPA are produced each year, making it one of the world’s most heavily used chemicals. BPA is used in baby bottles, drinking bottles, food storage containers, polyvinyl chloride, stretch films, paper, cardboard, medical equipment, and the epoxy resins lining most metallic food and beverage cans. BPA has estrogenic properties, and animal studies have linked low-level exposure to altered development of the male and female reproductive tract and brain as well as cancers of the mammary gland and prostate.The authors analyzed 24 biomonitoring studies involving blood serum samples from healthy adults, adults with certain diseases, pregnant women, and fetuses or fetal tissues. Overall, these studies indicate exposure to unconjugated BPA is in the range of 0.5–10 ng/mL, with most studies suggesting an average exposure of 1–3 ng/mL. The latter concentrations are higher than those shown to cause effects in human and animal cell cultures.The only data on BPA levels in children after birth is from studies of urine samples, most of which measured total (conjugated and unconjugated) BPA, but some of which measured unconjugated BPA separately from conjugated (inactive) BPA. The Centers for Disease Control and Prevention measured total BPA in urine samples from 314 children aged 6–11 years and 715 adolescents aged 12–19. Compared with adults, the younger children’s levels were highest, and adolescents were in-between. Other smaller studies also showed that BPA concentrations were higher in neonates and young children than in adults.Some of the studies measuring BPA in human blood were conducted using the enzyme-linked immunosorbent assay. Although this assay is considered less specific than the more precise analytical chemistry methods now favored for measuring BPA, the authors argue these studies are worthy of inclusion in their review because the concentrations they report are in line with what have been detected using the newer methods.The paper also points out “significant deficiencies” in the two studies that have examined the toxicokinetics of BPA exposure in humans, which they say have been given undue weight in regulatory decision making. The authors note we don’t yet know all the potential sources of exposure to BPA, which makes it impossible to predict toxicokinetics. Because the biomonitoring findings contradict the toxicokinetic studies, the authors recommend in a related commentary in the same issue [EHP 118(8):1051–1054; Vandenberg et al.] that biomonitoring data be considered in regulatory decision making whenever available rather than relying only on toxicokinetic models to estimate exposure.FiguresReferencesRelatedDetailsCited By Gugala N and Turner R (2018) The Potential of Metals in Combating Bacterial Pathogens Biomedical Applications of Metals, 10.1007/978-3-319-74814-6_6, (129-150), . Vol. 118, No. 8 August 2010Metrics About Article Metrics Publication History Originally published1 August 2010Published in print1 August 2010 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Biological monitoring of bisphenol A with HLPC/FLD and LC/MS/MS assays

Biological monitoring is a necessary process for risk assessment of endocrine disrupting chemicals (EDCs), particularly, bisphenol A (BPA), in breast milk, because its human risks are not clear yet, and infants, who feed on breast milk, are highly susceptible for EDCs. Concerning biological monitoring of BPA, the HPLC/FLD has been widely used before the LC/MS/MS. However, there was no report, which simultaneously evaluated the two methods in real analyses. Therefore, we analyzed BPA with LC/MS/MS and HPLC/FLD in human breast milk and conducted comparison of two methods in analyzed BPA levels. After establishing optimal condition, e.g. linearity, recovery, reproducibility and free BPA system, we analyzed BPA levels in human breast milk samples ( N = 100). The LOQs were similar in the two methods, i.e. 1.8 and 1.3 ng/mL for the HPLC/FLD and LC/MS/MS assays, respectively. There were strong associations between total BPA levels with the two methods ( R 2 = 0.40, p < 0.01), however, only 11% of them were analyzed as similar levels with 15% CVs. In addition, the detection range of BPA was broader in the HPLC method than the LC/MS/MS method. However, the BPA levels in the HPLC/FLD analysis were lower than those in the LC/MS/MS analysis ( p < 0.01). Thus, the differences in BPA levels between the two methods may come from mainly over-estimation with the LC/MS/MS method in low BPA samples and some of poor resolution with the HPLC/FLD in high BPA samples.

The time-concentration relationship of serum bisphenol A in male rats

To investigate the relationship of time-concentration of bisphenol A (BPA) in male Sprague-Dawley (SD) rats after single oral BPA administration. A total of 66 specific pathogen free (SPF) SD male rats were divided into 10 experimental groups and control group (n = 6). The experimental group rats were treated with BPA of 300 mg/kg by oral gavage and blood samples were taken from one group at 0.5, 1, 2, 4, 6, 12, 24, 36, 60, 84 h time point after oral administration, respectively. The serum BPA concentration was determined by fluorescence-high performance liquid chromatography (FL-HPLC) analysis. After oral administration of 300 mg/kg, the total serum BPA concentration of 17.13 microg/ml was the highest in rats at 1 h, then decreased, but it increased to 15.18 microg/ml again at 24 h, then gradually decreased to 0.51 microg/ml at 84 h. The level of serum free BPA was lower than that of total serum BPA after oral administration, the serum free BPA was 0.57 microg/ml at 0.5 h after oral administration. The serum free BPA level decreased to 0.06 microg/ml at 1 h, 0.03 microg/ml at 4 h, 0.01 microg/ml at 36 h after oral administration. The free BPA was only 4.15% (0.57/13.73) in total BPA in serum at 0.5 h after oral administration of 300 mg/kg BPA. These results suggested that conjugated BPA was the main metabolite of BPA in rat serum after single oral administration. Enterohepatic circulation of BPA glucuronide in rats may results in two peak levels of total BPA in serum.

Preterm Birth and Bisphenol A Concentrations in Mexico City: A Pilot Study

ISEE-0536 Background and Objectives: Preterm birth rates are increasing worldwide, which poses an important public health problem. Research on the role of environmental contaminants, including bisphenol-A (BPA), on the complex etiology of preterm birth remains relatively unexplored. We investigated the association of preterm delivery with BPA urinary concentrations in a preliminary nested case-control study. Methodology: Total (free + conjugated) BPA concentrations were measured in third trimester urine samples collected from 30 non-smoking women who delivered preterm (<37 weeks gestation) and 30 non-smoking controls (≥38 weeks gestation) of similar age, body mass index (BMI), and education from an ongoing Mexican birth cohort study. We compared geometric mean BPA concentrations between cases and controls using Student’s t-test, and calculated odd ratios (OR) for preterm birth associated with a natural log transformed (ln)-unit increase in BPA while adjusting for potential confounding variables (marital status, infant gender, delivery mode, and gestational age at time of urine sample) using multivariable logistic regression. Urine samples with non-detectable BPA concentrations (20% of samples) were assigned a value equal to one-half the limit of detection (LOD = 0.4 μg/L). Results: Geometric mean BPA concentrations were 1.20 μg/L in the preterm birth group compared to 0.66 μg/L in controls (P = 0.01). When correcting urine samples for dilution using specific gravity (SG), BPA concentrations were 1.23 μg/L among cases and 0.88 μg/L among controls (P-value = 0.11). Elevated odds for preterm birth were observed for an ln-unit increase in uncorrected (adjusted OR = 2.3; 95% CI 1.2–4.5) and SG-corrected (adjusted OR = 1.8; 95% CI 0.9–3.7) BPA concentration. Conclusions: To our knowledge, this is the first study to report exposure to BPA among pregnant women in Mexico. Our findings warrant further research on the relationship between exposure to BPA and preterm birth.

Sensitive and selective method for the determination of bisphenol-A and triclosan in serum and urine as pentafluorobenzoate-derivatives using GC–ECNI/MS

The development and validation of an analytical method is presented for the determination of bisphenol-A (BPA) and triclosan (TCS), two ubiquitous contaminants, in serum and urine. The glucuronidated metabolites were first turned into their free forms to determine total BPA and TCS. The determination consisted of a solid-phase extraction on Oasis HLB cartridges followed by an extractive derivatization with pentafluorobenzoylchloride. The extract was then purified on 10% (w/w) acidified silica and analyzed by gas chromatography–mass spectrometry in electron-capture negative ionization mode. Monitored ions were m/ z 616 and 406 for BPA and m/ z 482 and 287 for TCS, respectively. Limits of quantification were 0.5 ng/mL in serum and 0.2 ng/mL in urine for BPA and 0.1 ng/mL in serum and 0.05 ng/mL in urine for TCS. Method recoveries were between 76 and 110%, while repeatability was below 20%. The method was applied on 20 serum and 20 urine samples. The detection frequency in serum was 10% and 55% for BPA and TCS, respectively. BPA and TCS could be detected in all urine samples with median concentrations of 1.25 ng BPA/mL (range 0.58–5.20 ng/mL) and 1.71 ng TCS/mL (0.18–672 ng/mL).

From cans and containers to amniotic fluid: bisphenol a exposure during pregnancy

OBJECTIVE: To compare maternal and fetal exposure to bisphenol A (BPA), a widely used, endocrine disrupting chemical that may adversely effect fetal development. DESIGN: Cross-sectional study of BPA levels in sera of women undergoing second-trimester abortions and corresponding amniotic fluid. MATERIALS AND METHODS: Maternal sera and amniotic fluid were collected from women seeking second-trimester abortion at San Francisco General Hospital. Sample concentrations of BPA were determined in sample extracts by high performance liquid chromatography with an ESA CoulArray 5600 detector (detection limit 0.25 ng/mL). BPA levels were compared using the Wilcoxon signed rank test. RESULTS: Unconjugated (biologically active) BPA levels were statistically significantly higher in amniotic fluid than in maternal sera (p=0.05). Levels of total BPA were higher in amniotic fluid in 7 of the 9 samples but this difference was not significant (p=0.17) in this small sample.Tabled 1BPA Concentrations (ng/mL) in Maternal Sera (MS) and Amniotic Fluid (AF)Total∗Total=unconjugated+conjugated BPAConjugatedUnconjugatedIDMSAFMSAFMSAFratio117.625.14.23.313.421.81.621.22.30.52.10.70.20.2350.916.949.30.31.616.510.247.321.76.14.51.217.213.952.011.61.11.00.810.612.863.55.13.14.90.30.20.571.019.60.89.60.210.140.981.125.00.93.10.221.988.099.17.80.52.08.55.80.7median3.59.41.23.10.89.011.3∗ Total=unconjugated+conjugated BPA Open table in a new tab CONCLUSIONS: Our findings of increased total BPA in the majority of amniotic fluid samples, which continuously circulates through the fetus, and statistically higher unconjugated BPA levels suggest accumulation in the fetal environment that may lead to clinically-relevant effects on development. Increased unconjugated BPA in amniotic fluid is consistent with decreased fetal capacity to metabolize BPA.

Within-person variability in urinary bisphenol A concentrations: Measurements from specimens after long-term frozen storage

Bisphenol A (BPA) is an estrogenic contaminant of food and water associated with adverse developmental effects in laboratory animals. BPA has recently been linked to morbidity in adult humans, but studies of developmental effects in humans are methodologically more difficult. The ability to measure BPA in urine samples after long-term storage could aid in such studies. Because the half-life of BPA is < 6h, a single measurement would be useful only if the environmental exposure is relatively constant over weeks or months. Our aims were to evaluate the stability of BPA in specimens after 22-24 years of storage and to measure within-person temporal variability in urinary BPA. We measured total BPA concentration by mass spectrometry in first-morning urine samples from 60 premenopausal women. We selected from each woman's stored daily collections three urine samples approximately 2 and 4 weeks apart. Samples were selected from both the follicular and luteal phases of the menstrual cycle to assess cycle effects. Temporal variability was assessed with mixed model regression and correlations. BPA levels had an inter-quartile range from 1.1 to 3.1 ng/mg creatinine, slightly higher than levels in specimens from NHANES collected 3-11 years later. The Spearman correlation was approximately 0.5 for samples 2 weeks apart and 0.3 for samples 4 weeks apart. Menstrual cycle phase did not influence levels. BPA tended to increase during the three-year collection period, but not significantly. The similar distribution to NHANES samples and correlation of BPA levels taken at 2-week intervals provide indirect evidence that BPA is relatively stable during long-term freezer storage. The correlations indicate generally stable exposures over periods of weeks. These findings suggest that developmental effects of BPA exposure could be investigated with measurements from stored urine.

Bisphenol A Adsorption Onto Metals Oxides and Organic Materials in the Natural Surface Coatings Samples (NSCSs) and Surficial Sediments (SSs): Inhibition for the Importance of Mn Oxides

Selective extraction techniques followed by batch adsorption experiments and statistical analyses were employed to investigate the adsorption behavior of bisphenol A (BPA) onto the natural surface coatings samples (NSCSs) and surficial sediments (SSs) and estimate the relative contribution of components (i.e. Fe oxides, Mn oxides, organic materials and residues) to the total BPA adsorption. The results indicate that nonlinear Langmuir model can describe the adsorption behavior of BPA on the NSCSs and SSs before and after extraction treatments. The removal of Mn oxides from the NSCSs and SSs caused a significant increase in BPA adsorption, which implied that Mn oxides inhibited BPA adsorption onto solid matrix, and Fe oxides played a positive role in BPA adsorption onto the NSCSs and SSs. However, the removal of organic materials (OMs) led to a dramatic decrease in BPA adsorption, suggesting considerable amounts of BPA adsorbed onto OMs in the NSCSs and SSs. This study may provide important insights into the understanding of the transport and ultimate fate of BPA in the aquatic environments.

NTP‐CERHR expert panel report on the reproductive and developmental toxicity of bisphenol A

Robert E. Chapin, Jane Adams, Kim Boekelheide, L. Earl Gray Jr, Simon W. Hayward, Peter S.J. Lees, Barry S. McIntyre, Kenneth M. Portier, Teresa M. Schnorr, Sherry G. Selevan, John G. Vandenbergh, and Susan R. Woskie Pfizer, Inc., Groton, CT University of Massachusetts, Boston, MA Brown University, Providence, RI U.S. Environmental Protection Agency, Research Triangle Park, NC Vanderbilt University Medical Center, Nashville, TN Johns Hopkins University, Baltimore, MD Schering Plough Research Institute, Summit, NJ American Cancer Society, Atlanta, GA National Institute for Occupational Safety and Health, Cincinnati, OH U.S. Public Health Service (Ret), Silver Spring, MD North Carolina State University, Raleigh, NC University of Massachusetts, Lowell, MA

Maternal and fetal exposure to bisphenol A in Korea

Bisphenol A (BPA) is a well-known endocrine disrupter used widely. Despite the potential risk of human exposure to BPA, little information exists concerning maternal and fetal exposure to BPA during pregnancy in Korea. This study purposed to evaluate the correlation between maternal and fetal exposure, and to determine exposure levels to BPA in Korean pregnant women and their fetuses. Maternal blood and umbilical cord blood were collected from 300 subjects, and total BPA levels were measured. Blood BPA concentrations ranged from non-detectable to 66.48 μg/L in pregnant women and from non-detectable to 8.86 μg/L in umbilical cords. Serum BPA levels in most pregnant women were higher than in corresponding fetal umbilical cords and a positive correlation was found between in maternal and fetal BPA concentrations ( p < 0.05).

Determination of free and total bisphenol A in human urine to assess daily uptake as a basis for a valid risk assessment

Bisphenol A (BPA) is widely distributed and exhibits weak estrogenic activity. In contrast to BPA, the corresponding glucuronide metabolite is not estrogenic. Therefore, free and total BPA were determined in human urine samples to assess the significance of free BPA for risk assessment. In only 10% of 474 samples from 287 subjects was free BPA detected in a range from <LOD (0.3 μg/l) to 2.5 μg/l. Due to sample contamination with low amounts (∼1 μg/l) of BPA, house dust samples were independently collected in homes but not from persons who provide urine samples and analysed for BPA to check for potential sources of contamination. BPA was found in the range from 117 to 1 486 μg/kg (median: 553 μg/kg) dust. Additionally, BPA and d 16-BPA were administered to a volunteer to demonstrate the problem of contamination. In comparison to low levels of free BPA (<1.25 μg/l), no free d 16-BPA was observed. Therefore, the maximal concentration of 2.5 μg/l observed here may be considered as an exaggerated value as a result of contamination. Nevertheless, for risk assessment a concentration of 2.5 μg/l was used and this value is 800-fold below the tolerable daily intake (TDI) of 50 μg/kg. Total BPA was determined in 147 urine samples with concentrations between <LOD and 9.3 μg/l.

Cutaneous Penetration of Bisphenol A in Pig Skin

Bisphenol A (BPA) is an endocrine disruptor with weak estrogenic activity, used in epoxy resin and polycarbonate plastic. Human exposure may occur by contamination from food or food-contact material and by occupational scenarios. Occupational health hazards may be associated with allergic contact dermatitis (ACD) secondary to BPA exposure. Most ACD occurs in workers handling BPA products, such as plastic-product workers, and those exposed to epoxy adhesive tapes, foams, and dental products. The present study examined in vitro cutaneous penetration of BPA through pig skin, using a Franz cell. After 2, 5, and 10 h of exposure, total BPA skin content was 3, 6.9, and 11.4% of the applied dose, respectively. BPA remained essentially on the skin surface and penetration mainly accumulated in the dermis. As the pig skin model is a reliable predictor of percutaneous penetration in humans, these findings may be reassuring for workers in contact with BPA-based products.

Urinary bisphenol-A concentration in infertile Japanese women and its association with endometriosis: A cross-sectional study

Bisphenol A (BPA), a raw material commonly used in the manufacture of resins such as polycarbonate and epoxy, is a possible xenoestrogen that is hypothesized to disrupt the human endocrine system. Humans are widely exposed to BPA. We investigated the urinary concentration of BPA in infertile Japanese women and its possible association with endometriosis. We recruited 166 women (aged 20-45) who had complained of infertility and visited a university hospital in Tokyo. The subjects were interviewed and their urine samples were obtained prior to a laparoscopic diagnosis of endometriosis between January 2000 and December 2001. Urinary total BPA concentration in 140 eligible urine samples was then measured using enzymatic deconjugation of glucuronide and sulfate and high-performance liquid chromatography isotope-dilution tandem mass spectrometry. Median (25th-75th percentile) unadjusted and creatinine-adjusted urinary BPA concentrations were 1.6 (0.69-2.8) μg/L and 0.80 (0.45-1.3) μg/g creatinine. No significant monotonic association of endometriosis with urinary BPA concentration was observed. Median urinary BPA concentration in women with stage 0-1 endometriosis (0.74 μg/g creatinine) did not significantly differ from that in those with stage II-IV endometriosis (0.93 μg/g creatinine) (p for difference=0.24). This study, based on a larger number of samples than those in previous studies in Japan and using the most reliable analytical method currently available, showed that urinary concentrations of BPA in women who consulted a physician for infertility were not higher than those in other populations. Moreover, no association between urinary BPA concentration and endometriosis was found in this cross-sectional study.

Exposure of the U.S. Population to Bisphenol A and 4- tertiary -Octylphenol: 2003–2004

BackgroundBisphenol A (BPA) and 4-tertiary-octylphenol (tOP) are industrial chemicals used in the manufacture of polycarbonate plastics and epoxy resins (BPA) and nonionic surfactants (tOP). These products are in widespread use in the United States.ObjectivesWe aimed to assess exposure to BPA and tOP in the U.S. general population.MethodsWe measured the total (free plus conjugated) urinary concentrations of BPA and tOP in 2,517 participants ≥ 6 years of age in the 2003–2004 National Health and Nutrition Examination Survey using automated solid-phase extraction coupled to isotope dilution–high-performance liquid chromatography–tandem mass spectrometry.ResultsBPA and tOP were detected in 92.6% and 57.4% of the persons, respectively. Least square geometric mean (LSGM) concentrations of BPA were significantly lower in Mexican Americans than in non-Hispanic blacks (p = 0.006) and non-Hispanic whites (p = 0.007); LSGM concentrations for non-Hispanic blacks and non-Hispanic whites were not statistically different (p = 0.21). Females had statistically higher BPA LSGM concentrations than males (p = 0.043). Children had higher concentrations than adolescents (p < 0.001), who in turn had higher concentrations than adults (p = 0.003). LSGM concentrations were lowest for participants in the high household income category (> $45,000/year).ConclusionsUrine concentrations of total BPA differed by race/ethnicity, age, sex, and household income. These first U.S. population representative concentration data for urinary BPA and tOP should help guide public health research priorities, including studies of exposure pathways, potential health effects, and risk assessment.

Sample clean-up with sol–gel enzyme and immunoaffinity columns for the determination of bisphenol A in human urine

The paper describes the development of a simple and highly selective analytical method for the determination of free and total bisphenol A in urine samples. Free bisphenol A levels can be determined after sample clean-up using sol–gel immunoaffinity columns containing anti-bisphenol A antibodies. In determining total bisphenol A levels, the sample pre-treatment procedure consists of sample preparation using an on-line combination of two sol–gel columns, an enzyme column containing glucuronidase and arylsulfatase, and an immunoaffinity column. Bisphenol A can then be quantified by high-performance liquid chromatography and fluorescence detection. The mean recovery was found to be 78% with a standard deviation of 3.4%, the LOD (S/N = 3) was 0.2 ng/ml. The method was applied to determine free and total urinary BPA levels of healthy adults and dialysis patients.