DNA methylation changes in whole blood is associated with exposure to the environmental contaminants, mercury, lead, cadmium and bisphenol A, in women undergoing ovarian stimulation for IVF.

BACKGROUND: Changes in DNA methylation may play an important role in the deleterious reproductive effects reported in association with exposure to environmental pollutants. In this pilot study, we identify candidate methylation changes associated with exposure to pollutants in women undergoing in vitro fertilization (IVF). METHODS: Blood and urine were collected from women on the day of oocyte retrieval. Whole blood was analyzed for mercury and lead, and urine for cadmium using inductively coupled plasma mass spectrometry. Unconjugated bisphenol A (BPA) was analyzed in serum using high-performance liquid chromatography with Coularray detection. Participants were dichotomized as higher or lower exposure groups by median concentrations. Using the Illumina GoldenGate Methylation Cancer Panel I, DNA methylation in whole blood from 43 women was assessed at 1505 CpG sites for association with exposure levels of each pollutant. Candidate CpG sites were identified using a Diff Score >|13| (P< 0.05) and an absolute difference >10% which were confirmed using bisulfite pyrosequencing. RESULTS: Methylation of the GSTM1/5 promoter was increased for women with higher mercury exposure (P= 0.04); however, no correlation was observed (r= 0.17, P= 0.27). Reduced methylation was detected in the COL1A2 promoter in women with higher exposure to lead (P= 0.004), and an inverse correlation was observed (r = - 0.45, P= 0.03). Lower methylation of a promoter CpG site at the TSP50 gene was detected in women with higher BPA exposure (P= 0.005), and again an inverse correlation was identified (r = - 0.51, P= 0.001). CONCLUSIONS: Altered DNA methylation at various CpG sites was associated with exposure to mercury, lead or BPA, providing candidates to be investigated using a larger study sample, as the results may reflect an independently associated predictor (e.g. socioeconomic status, diet, genetic variants, altered blood cell composition). Further studies accommodating variations in these factors will be needed to confirm these associations and identify their underlying causes.

Development of an analytical method for simultaneously determining TBBPA and HBCDs in various foods.

Tetrabromobisphenol A (TBBPA) and Hexabromocyclododecanes (HBCDs) are commonly used as brominated flame retardants in large volumes, and accumulate in plants and animals in the environment, and people are exposed to them when consuming food. As many countries are monitoring them in food, it is necessary to develop a method to analyze them simultaneously for cost efficiency. A method was developed and optimized under different conditions using accelerated solvent extraction to extract the lipids from the samples, acid silica column to clean the samples and liquid chromatography coupled with tandem mass spectrometry to determine TBBPA and HBCDs. The method was validated in different kinds of food. Uncertainty of measurement was calculated by combining all uncertainties of contributors. Intermediate precision (reproducibility) was the most influential contributor to uncertainty. 5 food categories with 115 samples were analyzed with the method, and mackerels containing high level of fat were highly contaminated by TBBPA and HBCDs.

Assessment of Tetrabromobisphenol and Hexabromocyclododecanes exposure and risk characterization using occurrence data in foods.

Tetrabromobisphenol A (TBBPA) and Hexabromocyclododecanes (HBCDs) are two of the most used BFRs and they have cumulated in the environment. TBBPA and HBCDs in food were determined and their risks were assessed. The analytical method used was validated in different food categories, and the performance parameters were acceptable based on the criteria of AOAC. Fish and cephalopods were contaminated with TBBPA higher than other foods, and fish contained higher levels of HBCDs than other foods. α-HBCD was the predominant diastereomer in fish and meat and had strong correlations with HBCDs in fish and cephalopods. HBCDs accumulated easier than TBBPA in food. People were exposed to TBBPA from 0.125 ng kg-1 b.w. day-1 to 0.284 ng kg-1 b.w. day-1 and HBCDs from 0.353 ng kg-1 b.w. day-1 to 1.006 ng kg-1 b.w. day-1 via food and air. Food mainly contributed to exposure to TBBPA and HBCDs and vegetables were the main contributors for exposure to TBBPA and HBCDs in food. MOEs for the whole population were over 100, and the risks of exposure to TBBPA and HBCDs from food and the environment were of low concern to public health.

Fumonisins B1 and B2 in agricultural products consumed in South Korea: an exposure assessment.

To survey fumonisins B1 (FB1) and B2 (FB2) in agricultural products consumed in South Korea and provide an exposure assessment, ground samples were extracted (80% MeOH), filtered (0.2 microm), and cleaned up. After evaporation, dry residues were reconstituted in 50% MeOH, and a 50-micro1 aliquot of this sample was mixed with 200 micro1 of o-phthaldialdehyde for derivatization. The derivatives were analyzed with a high-performance liquid chromatography system equipped with a fluorescence detector. For validation of the detection procedure, linearity, accuracy, precision, detection limit, and quantification limit were determined. The validated detection method was then used to survey fumonisins in white rice, brown rice, barley, barley tea, beer, wheat flour, millet, dried corn, corn flour, corn tea, canned corn, popcorn, and breakfast cereal. Retention times for FB1 and FB2 standards were 7 and 18 min, respectively. Linearity (R2 = 0.99995 to 0.99998), accuracy (81.47 to 108.83%), precision (2.35 to 5.77), detection limit (25 ng/g or ng/ml), and quantification limit (37 ng/g or ng/ml) indicated that this procedure is capable of quantifying fumonisins in agricultural products. Only FB1-positive samples (5.12%, three dried corn samples and five corn flour samples) were found at 90.89 to 439.67 ng/g. According the survey results, an estimated daily intake of FB1 and FB2 in Korea was 0.087 ng/kg of body weight per day. These results indicate that continuous monitoring of these mycotoxins is necessary to establish appropriate risk assessment, and the maximum tolerable daily intake of fumonisins in Korea is lower than the 2 microg/kg set by the Joint Food and Agriculture Organization-World Health Organization Expert Committee.

Determination of plutonium isotopes (238,239,240Pu) and strontium (90Sr) in seafood using alpha spectrometry and liquid scintillation spectrometry.

The present study was carried out to survey the levels of plutonium isotopes (238,239,240Pu) and strontium (90Sr) in domestic seafood in Korea. In current, regulatory authorities have analyzed radionuclides, such as 134Cs, 137Cs and 131I, in domestic and imported food. However, people are concerned about contamination of other radionuclides, such as plutonium and strontium, in food. Furthermore, people who live in Korea have much concern about safety of seafood. Accordingly, in this study, we have investigated the activity concentrations of plutonium and strontium in seafood. For the analysis of plutonium isotopes and strontium, a rapid and reliable method developed from previous study was used. Applicability of the test method was verified by examining recovery, minimum detectable activity (MDA), analytical time, etc. Total 40 seafood samples were analyzed in 2014-2015. As a result, plutonium isotopes (238,239,240Pu) and strontium (90Sr) were not detected or below detection limits in seafood. The detection limits of plutonium isotopes and strontium-90 were 0.01 and 1 Bq/kg, respectively.

Harmonized Collaborative Validation of Aflatoxins and Sterigmatocystin in White Rice and Sorghum by Liquid Chromatography Coupled to Tandem Mass Spectrometry.

An interlaboratory study was performed in eight laboratories to validate a liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous determination of aflatoxins and sterigmatocystin (STC) in white rice and sorghum (Sorghum bicolor). Fortified samples (at three different levels) of white rice and sorghum were extracted, purified through a solid-phase extraction (SPE) column, and then analyzed by LC/MS/MS. The apparent recoveries (ARs) ranged from 78.8% to 95.0% for aflatoxins and from 85.3% to 96.7% for STC. The relative standard deviations for repeatability (RSDr) and reproducibility (RSDR) of aflatoxins were in the ranges 7.9%-33.8% and 24.4%-81.0%, respectively. For STC, the RSDr ranged from 7.1% to 40.2% and the RSDR ranged from 28.1% to 99.2%. The Horwitz ratio values for the aflatoxins and STC ranged from 0.4 to 1.2 in white rice and from 0.3 to 1.0 in sorghum, respectively. These results validated this method for the simultaneous determination of aflatoxins and STC by LC/MS/MS after SPE column cleanup. The percentages of satisfactory Z-score values (|Z| ≤ 2) were the following: for white rice, 100% for aflatoxins and STC; for sorghum, 100%, except in data from two laboratories for STC (0.3 µg/kg). This validated that the LC/MS/MS method was successfully applied for the determination of aflatoxins and STC in 20 white rice and 20 sorghum samples sourced from Korean markets.

A pilot study of seafood consumption and exposure to mercury, lead, cadmium and arsenic among infertile couples undergoing in vitro fertilization (IVF).

This cross-sectional pilot study was conducted to assess environmental exposures to toxic elements through seafood consumption, among infertile couples undergoing in vitro fertilization (IVF). Twenty-five women and 15 men completed a questionnaire, and provided biologic specimens for quantification of Hg, Pb, Cd, and As using ICP-MS. Consumption of 'mollusks' and 'shellfish' are associated with increased blood Hg. Other seafood consumption predicts blood Pb, and urine Cd and As. Though limited by small numbers and the cross-sectional design, these results suggest that consumption of specific seafood items increases exposure to toxic elements in couples undergoing IVF.

Toxic trace metals and embryo quality indicators during in vitro fertilization (IVF).

Trace exposures to the toxic metals mercury (Hg), cadmium (Cd) and lead (Pb) may interfere with in vitro fertilization (IVF). The aim of this study is to explore biologically plausible hypotheses concerning associations between metals and embryo quality indicators during IVF. For 24 female patients, a multivariable ordinal logistic regression model suggests a 75% reduction in the odds for higher embryo cell cleavage per µg/dL increase in blood Pb (adjusted odds ratio (aOR) 0.25, 95% confidence interval (CI) 0.07-0.86). For 15 male partners, each µg/L increase in blood Hg (aOR 0.60, 95% CI 0.45-0.79) and µg/dL increase in blood Pb (aOR 0.58, 95% CI 0.37-0.91) is associated with a decrease in the analogous odds. Embryo fragmentation is reduced by higher blood Hg (aOR 0.85, 95% CI 0.72-1.00), but increased by higher blood Pb (aOR 1.47, 95% CI 1.11-1.94) in men. The magnitude of these suggested effects warrants confirmation in a larger study.

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.

Serum unconjugated bisphenol A concentrations in men may influence embryo quality indicators during in vitro fertilization.

Here we assess bisphenol A (BPA) in couples undergoing in vitro fertilization (IVF) and indicators of embryo quality; embryo cell number (ECN) and embryo fragmentation score (EFS). Twenty-seven couples provided serum on the day of oocyte retrieval. Unconjugated BPA was measured by HPLC with Coularray detection. Odds ratios (OR) were generated using ordinal logistic regression including female and male BPA concentrations, age and race, and day of embryo transfer for ECN. Inverse associations are suggested for male BPA with ECN (OR=0.70, P=0.069), and EFS (OR=0.54, P=0.009), but not for women. Male BPA exposure may affect embryo quality during IVF.

Bisphenol A exposure reduces the estradiol response to gonadotropin stimulation during in vitro fertilization.

OBJECTIVE: To investigate associations between serum bisphenol A (BPA) concentrations and follicular response to exogenous ovary stimulation. DESIGN: Fasting serum was prospectively collected on the day of oocyte retrieval and assessed for unconjugated BPA using high-performance liquid chromatography with Coularray detection. Multivariable linear regression and negative binomial regression were used to assess associations between concentrations of BPA and outcome measures. Models were adjusted for race/ethnicity, antral follicle count at baseline, and cigarette smoking. SETTING: A reproductive health center. PATIENT(S): Forty-four women undergoing IVF. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Peak E(2) level and the number of oocytes retrieved during IVF. RESULT(S): The median unconjugated serum BPA concentration is 2.53 ng/mL (range = 0.3-67.36 ng/mL). Bisphenol A is inversely associated with E(2) (ß = -0.16; 95% confidence interval = -0.32, 0.01), as well as with E(2) normalized to the number of mature-sized follicles at the hCG trigger (ß = -0.14; 95% confidence interval = -0.24, -0.03). No association is observed for BPA and the number of oocytes retrieved (adjusted risk ratio = 0.95; 95% confidence interval = 0.82, 1.10). CONCLUSION(S): Bisphenol A is associated with a reduced E(2) response during IVF. Although limited by the preliminary nature of this study, these results merit confirmation in a future comprehensive investigation.

Natural occurrence of type-B trichothecene mycotoxins in Korean cereal-based products.

Type-B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), fusarenone-X (FUS-X), 15-acetyldeoxynivalenol (15ADON), and 3-acetyldeoxynivalenol (3ADON)) were determined in 338 cereal-based products. Detection limit, quantification limit and mean recovery for five toxins were in the ranges 0.7-2.6 µg kg(-1), 2.1-7.8 µg kg(-1) and 73-110%, respectively. The range of occurrence and average level in samples were, respectively, 21-88% and 5.2-121.8 µg kg(-1) for NIV, 10-96% and 1.7-109.5 µg kg(-1) for DON, 2-39% and 0.4-3.6 µg kg(-1) for FUS-X, 0-80% and 0-17.3 µg kg(-1) for 15ADON, and 0-29% and 0-1.5 µg kg(-1) for 3ADON. Regarding co-occurrence, 64% of samples had more than two type-B trichothecenes. The estimated daily intakes of NIV, DON, FUS-X, 15ADON, and 3ADON were 0.077, 0.048, 0.004, 0.006 and 0.002 µg kg(-1) bw day(-1), respectively. These results suggest that current exposure levels do not indicate the possibility of adverse effects, but consideration of the combined exposure of type-B trichothecenes may be required due to the high frequency of co-occurrence.