Levels of di-(2-ethylhexyl)phthalate and total phthalate esters in milk, cream, butter and cheese

Connecting the Dots: Livestock Animals as Missing Links in the Chain of Microplastic Contamination and Human Health

Plastic pollution is a global diffuse threat, especially considering its fragmentation into microplastics (MPs) and nanoplastics (NPs). Since the contamination of the aquatic environment is already well studied, most studies have now focused on the soil. Moreover, the number of studies on the exposure routes and toxic effects of MNPs in humans is continuously increasing. Although MNPs can cause inflammation, cytotoxicity, genotoxicity and immune toxicity in livestock animals, which can accumulate ingested/inhaled plastic particles and transfer them to humans through the food chain, research on this topic is still lacking. In considering farm animals as the missing link between soil/plant contamination and human health effects, this paper aims to describe their importance as carriers and vectors of MNP contamination. As research on this topic is in its early stages, there is no standard method to quantify the amount and the characteristics of MNPs in different matrices. Therefore, the creation of a common database where researchers can report data on MNP characteristics and quantification methods could be helpful for both method standardization and the future training of an AI tool for predicting the most abundant/dangerous polymer(s), thus supporting policy decisions to reduce plastic pollution and perfectly fitting with One Health principles.

Analysis of ortho-phthalates and other plasticizers in select organic and conventional foods in the United States

BACKGROUND

ortho-phthalates and other plasticizers impart flexibility to plastics in food production, processing, and packaging; food consumption is a dominant plasticizer exposure pathway. Lower molecular weight ortho-phthalates are being replaced in plastic products due to toxicity concerns, but toxic hazards of and exposures to replacement ortho-phthalates and other plasticizers are poorly understood.

OBJECTIVE

We measured 12 ortho-phthalates and 9 other plasticizers in conventional and organic U.S. food products to assess magnitude and profiles of contamination.

METHODS

We measured plasticizers in 34 vegetable oils, 10 milks, 18 infant formulas, and 9 cheese powders from macaroni kits using gas chromatography coupled with mass spectrometry (GC-MS). We analyzed plastic packaging composition using FTIR spectroscopy.

RESULTS

We detected eight ortho-phthalates and three alternatives ((1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), diethylhexyl terephthalate (DEHT), and diisobutyl adipate (DIBA). Diethylhexyl phthalate (DEHP) was measured in all 71 products. DEHT had the highest concentration of any plasticizer (>10,000 ng/g in three oils). Oils had the highest total plasticizer (median = 770 ng/g, max = 14,900 ng/g) and milk the lowest (median = 88 ng/g, max = 120 ng/g). Organic milk and refined oils had higher median plasticizer levels than conventional. Refined oils had significantly lower concentrations than unrefined oils. Maximum contributors for every category were non-ortho-phthalates: DEHT (powdered infant formula and oils) and DIBA (cheese powder, milk and liquid formula). Plasticizers were not detected in packaging except epoxidized soybean oil in liquid formula lids.

IMPACT STATEMENT

Human exposure to plasticizers is a significant public health concern. Nevertheless, sources of such exposures are poorly characterized. This study adds valuable information for estimating legacy and alternative plasticizer exposures from foods. The method developed for measuring DINCH, DINP and DIDP broadens the range of plasticizers other researchers may analyze in future work. The profiles of plasticizer contamination varied depending on the food type. We also document that food processing may be a source of plasticizer contamination in foods.

Determination of phthalic acid esters (PAEs) along with probabilistic health risk assessment in fruit juice samples in Tehran, Iran

In the present study, magnetic solid phase extraction (MSPE) method and gas chromatography-mass spectrometry (GC/MS) technique were used to measure 6 PAE in fruit juice samples. The mean of total phthalic acid esters (ƩPAEs) in all samples was 3.55 ± 0.66 µg/L. The mean concentration of DEHP (bis(2-ethylhexyl) phthalate) in samples was 0.82 ± 0.31 µg/L, which was lower than the mentioned United States Environmental Protection Agency (USEPA) standard level in drinking water (6 μg/L for DEHP). The pineapple juice samples (4.44 ± 0.57 µg/L) and mango juice samples (2.77 ± 0. 1 µg/L) had maximum and minimum mean levels of ƩPAEs, respectively. Also, results showed that brand B (3.76 ± 0.87 µg/L) and samples in the time of expiration date (3.64 ± 0.72 µg/L) had the highest PAE levels. The rank order Chronic Daily Intake (95%) values for adults were DEHP ([Formula: see text]) > butylbenzyl phthalates (BBP) ([Formula: see text]) > diethyl phthalate (DEP) ([Formula: see text]) and for children were DEHP ([Formula: see text]) > BBP (9.07E-04) > DEP ([Formula: see text]), which were below the tolerable daily intake (TDI) value. The noncancer risk of PAEs based on the target hazard quotient (THQ) was acceptable (< 1). The results exhibited that the Incremental Lifetime Cancer Risk (ILCR) was below the permissible limit (< [Formula: see text]). Therefore, the risk of carcinogenicity and noncarcinogenicity of PAEs in juices does not have adverse effects on human health.

In utero di-(2-ethylhexyl) phthalate-induced testicular dysgenesis syndrome in male newborn rats is rescued by taxifolin through reducing oxidative stress

Testicular dysgenesis syndrome in male neonates manifests as cryptorchidism and hypospadias, which can be mimicked by in utero phthalate exposure. However, the underlying phthalate mediated mechanism and therapeutic effects of taxifolin remain unclear. Di-(2-ethylhexyl) phthalate (DEHP) is the most abundantly used phthalate and can induce testicular dysgenesis syndrome in male rats. To explore the mechanism of DEHP mediated effects and develop a therapeutic drug, the natural phytomedicine taxifolin was used. Pregnant Sprague-Dawley female rats were daily gavaged with 750 mg/kg/d DEHP or 10 or 20 mg/kg/d taxifolin alone or in combination from gestational day 14 to 21, and male pup's fetal Leydig cell function, testicular MDA, and antioxidants were examined. DEHP significantly reduced serum testosterone levels of male pups, down-regulated the expression of SCARB1, CYP11A1, HSD3B1, HSD17B3, and INSL3, reduced the cell size of fetal Leydig cells, decreased the levels of antioxidant and related signals (SOD2 and CAT, SIRT1, and PGC1α), induced abnormal aggregation of fetal Leydig cells, and stimulated formation of multinucleated gonocytes and MDA levels. Taxifolin alone (10 and 20 mg/kg/d) did not affect these parameters. However, taxifolin significantly rescued DEHP-induced alterations. DEHP exposure in utero can induce testicular dysgenesis syndrome by altering the oxidative balance and SIRT1/PGC1α levels, and taxifolin is an ideal phytomedicine to prevent phthalate induced testicular dysgenesis syndrome.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Metabolomics and Data-Driven Bioinformatics Revealed Key Maternal Metabolites Related to Fetal Lethality via Di(2-ethylhexyl)phthalate Exposure in Pregnant Mice

We performed serum metabolome analysis of di(2-ethylhexyl)phthalate (DEHP)-exposed and control pregnant mice. Pregnant mice (n = 5) were fed a DEHP-containing diet (0.1% or 0.2% DEHP) or a normal diet (control) from gestational days 0-18. After maternal exposure to 0.2% DEHP there were no surviving fetuses, indicating its strong fetal lethality. There were no significant differences in the numbers of fetuses and placentas between the 0.1% DEHP and control groups, although fetal viability differed significantly between them, suggesting that maternal exposure to 0.1% DEHP could inhibit fetal growth. Metabolomics successfully detected 169 metabolites in serum. Principal component analysis (PCA) demonstrated that the three groups were clearly separated on PCA score plots. The biological interpretation of PC1 was fetal lethality, whereas PC2 meant metabolic alteration of pregnant mice via DEHP exposure without fetal lethality. In particular, the first component was significantly correlated with fetal viability, demonstrating that maternal metabolome changes via DEHP exposure were strongly related to fetal lethality. Levels of some amino acids were significantly increased in the DEHP-exposed groups, whereas those of some fatty acids, nicotinic acid, and 1,5-anhydroglucitol were significantly decreased in the DEHP groups. DEHP-induced increases in glycine levels could cause fetal neurological disorders, and decreases in nicotinic acid could inhibit fetal growth. In addition, a machine-learning Random forest could determine 16 potential biomarkers of DEHP exposure, and data-driven network analysis revealed that nicotinic acid was the most influential hub metabolite in the metabolic network. These findings will be useful for understanding the effects of DEHP on the maternal metabolome in pregnancy and their relationship to fetal lethality.

The effects of packaging type and storage temperature on some of UHT milk quality indexes

The objective of the present study was to illustrate the changes in physicochemical properties in ultra-high temperature (UHT) milk packed into a pouch and Tetra Brik during storage. UHT milk samples were kept at 5 and 25 °C for 3 months and regularly analyzed monthly. During storage, significant increases (p < 0.05) in titratable acidity (TA), water-soluble nitrogen (WSN), and non-protein nitrogen (NPN) when UHT milk was packed into pouch versus Tetra Brik and stored at 25 versus 5 °C. Neither type of packaging nor storage temperature affect pH values during storage. Spore-forming bacterial (SFB) count was always higher in UHT milk packed into pouch versus Tetra Brik. Refrigerated storage kept UHT milk without detectable SFB compared to UHT milk held at 25 °C. Pouch packages were responsible for the migration of phthalate derivatives [dimethyl phthalate "DMP", diethyl phthalate "DEP", dibutyl phthalate "DBP", and di-(2-Ethylhexyl) phthalate "DEHP"] into milk with significantly greater levels than milk filled into Tetra Brik. The total sensory scores were decreased significantly during storage, which was more pronounced in UHT milk filled into pouch versus Tetra Brik or stored at 25 °C versus 5 °C. It is concluded that UHT milk filled into Tetra Brik stored at 5 and 25 °C is better in terms of quality and safety indexes than such filled into a pouch.

Evaluation of portable vibrational spectroscopy for identifying plasticizers in dairy tubing

Plasticisers are commonly used to increase the flexibility of a wide variety of food contact materials including the plastic tubing, liners, and gaskets used in the dairy industry. In recent years, some classes of plasticisers have come under scrutiny due to the potential for transfer of these compounds into the milk itself, which can then be further processed into foods such as powdered milks and cheeses, infant formula, and baked goods. One such set of plasticisers that is being evaluated for frequency of use, potential routes of exposure, and risk to consumers is ortho-phthalates, hereafter referred to as phthalates. In order to better understand the actual use of phthalate versus non-phthalate plasticised tubing, a robust, rapid, and portable analytical method is necessary for on-site screening. Laboratory Raman and near-infrared spectrometers have been used extensively for polymer and additive evaluation, and advances in portable/hand-held technology could lead to feasible plasticiser evaluation in the field. This research overviews efforts to evaluate six portable spectroscopy devices for their ability to identify phthalate versus non-phthalate plasticised polyvinyl chloride (PVC) dairy tubing, liners, and gaskets. The most successful method, a hand-held Raman spectrometer along with a plasticiser spectral library or a chemometric model, can rapidly and accurately identify phthalate containing PVC and has the potential to be employed as a future field screening technique for regulators and the dairy industry.

Pregnane X Receptor Mediates Atherosclerosis Induced by Dicyclohexyl Phthalate in LDL Receptor-Deficient Mice

Plastic-associated endocrine disrupting chemicals (EDCs) have been implicated in the etiology of cardiovascular disease (CVD) in humans, but the underlying mechanisms remain elusive. Dicyclohexyl phthalate (DCHP) is a widely used phthalate plasticizer; whether and how exposure to DCHP elicits adverse effects in vivo is mostly unknown. We previously reported that DCHP is a potent ligand of the pregnane X receptor (PXR) which acts as a xenobiotic sensor to regulate xenobiotic metabolism. PXR also functions in macrophages to regulate atherosclerosis development in animal models. In the current study, LDL receptor-deficient mice with myeloid-specific PXR deficiency (PXRΔMyeLDLR-/-) and their control littermates (PXRF/FLDLR-/-) were used to determine the impact of DCHP exposure on macrophage function and atherosclerosis. Chronic exposure to DCHP significantly increased atherosclerotic lesion area in the aortic root and brachiocephalic artery of PXRF/FLDLR-/- mice by 65% and 77%, respectively. By contrast, DCHP did not affect atherosclerosis development in PXRΔMyeLDLR-/- mice. Exposure to DCHP led to elevated expression of the scavenger receptor CD36 in macrophages and increased macrophage form cell formation in PXRF/FLDLR-/- mice. Our findings provide potential mechanisms underlying phthalate-associated CVD risk and will ultimately stimulate further investigations and mitigation of the adverse effects of plastic-associated EDCs on CVD risk in humans.

Characterization of diphenyl phthalate as an agonist for estrogen receptor: an in vitro and in silico study

Phthalate esters (PAEs) are important pollutants in the environment, which can interfere with the endocrine system by mimicking estrogen. However, limited information is available on modulating the estrogen receptor (ER) of five PAEs including di (2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), benzyl butyl phthalate (BBP), diphenyl phthalate (DPhP) and dicyclohexyl phthalate (DCHP). This study evaluated the agonistic effects of PAEs on human ER. The cytotoxicity assay showed that there were a significant inhibition of the cell proliferation with treatment of five PAEs. Moreover, DPhP does-dependently enhanced ER-mediated transcriptional activity in the reporter gene assay. The increased expression of estrogen-responsive genes (TFF1, CTSD, and GREB1) was also observed in MCF-7 cells treated with DPhP. The result of molecular docking showed that DPhP tended to bind to the agonist conformation of ER compared with the antagonist conformation of ER, demonstrating its agonist characteristic that has been confirmed in the reporter gene assay. Thus, we found that DPhP may be evaluated as an ER agonist in vitro and it can interfere with the normal function of human ER.

Phthalate Exposure Pattern in Breast Milk within a Six-Month Postpartum Time in Southern Taiwan

Di-(2-ethylhexyl) phthalate (DEHP), a common plasticizer, has been detected in breast milk in many countries; however, whether phthalate metabolite concentration and the detection rate in breast milk change postpartum is still unknown. We measured phthalate metabolite concentrations in breast milk in the first 6 months postpartum in women enrolled in the E-Da hospital from January to July 2017. A total of 56 breastfeeding mothers and 66 samples were included in this study. We analyzed the samples’ concentration of eight phthalate metabolites using liquid chromatography mass spectrometry. The concentration of mono-2-ethylhexyl phthalate (MEHP) was significantly higher in the first month, and then decreased over time. The detection rate of ono-isobutyl phthalate (MiBP) and mono-n-butyl phthalate (MBP) was low in the first month and then increased over time. Compared with a previous study published in 2011, the levels of MEHP and MiBP in breast milk were much lower in the present study, suggesting an increased awareness of the health risks of phthalate exposure after a food scandal occurred in Taiwan. This study provides information for evaluating newborns’ exposure to different kinds of phthalate through human milk in the postpartum period.

Migration of food contact substances into dry foods: A review

A comprehensive review of the literature was performed on migration of substances from packaging materials into dry foods, specifically those with surfaces containing no free fats or oils. Historically, migration from food packaging to dry foods has been assumed to be minimal. However, several recent publications have reported concentrations of migrants into dry foods that are substantially higher than anticipated. The goal of this review is to provide a comprehensive summary of recent studies that examined migration to dry foods or dry food simulants, observe and assess common migrants, and report the highest migration values. Focusing on the packaging materials and migrants that exhibit the highest migration values, this review divided the studies into two categories: 1) analysis of food products in commercial packaging taken directly from grocery store shelves, and 2) analysis of food products and food simulants in contact with packaging or other material fortified with known quantities of a migrant. Discussions include the examination of migration testing methods, viability of different food simulants, and variables that affect migration behaviour. These include the physicochemical properties of both the migrant and food (i.e. volatility, molecular size, structure, food composition and particle size) and factors pertaining to the packaging material and the environment (i.e. temperature, humidity, and the presence of a secondary barrier). Information gaps and remaining questions are also identified and discussed.

Phthalate pollution: environmental fate and cumulative human exposure index using the multivariate analysis approach

A comprehensive review was performed on the environmental fate, environmental occurrence, toxicity, physical-chemical properties, abiotic and biotic removal and degradation of phthalate esters (PAEs) to compute the overall phthalate exposure and their impact on human beings. The removal and degradation of these wide spread pollutants by abiotic processes such as hydrolysis and photodecomposition are very slow and insignificant. On the other hand, the breakdown of PAEs by microorganisms is considered to be one of the major routes of environmental degradation for these widespread pollutants. Numerous microbial strains have been reported to degrade these compounds under aerobic, anaerobic and facultative conditions. Concurrently, the environmental fate, transport and transformation/degradation of these compounds under natural conditions are highly dependent on their physical and chemical properties. In order to understand the relationship between the concentrations of PAEs of different environmental compartments and human exposure prospects, a novel average phthalate pollution index (PPI) and cumulative phthalate exposure index (PEI) were proposed using the multivariate analysis approach. These indices were computed on the basis of relative importance, environmental occurrence, toxicity, physical-chemical properties, abiotic and biotic removal and degradation of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP) and diethyl-hexyl phthalate (DEHP). At present, the average PPI and cumulative PEI of 29 countries were evaluated using the concentrations of PAEs reported in the literature. These indices signify the overall phthalate pollution, human exposure and their interrelation. According to the index, Slovakia, Canada, Taiwan, Sweden and South Africa are among the top five countries in terms of cumulative phthalate exposure as per the existing data. The exposure percentage of total PAEs significantly varies between 23 and 44% since many environmental compartments are not directly exposed to human beings and they are degraded under natural conditions.

Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.

Critical Review on the Presence of Phthalates in Food and Evidence of Their Biological Impact

Phthalates are a huge class of chemicals with a wide spectrum of industrial uses, from the manufacture of plastics to food contact applications, children's toys, and medical devices. People and animals can be exposed through different routes (i.e., ingestion, inhalation, dermal, or iatrogenic exposure), as these compounds can be easily released from plastics to water, food, soil, air, making them ubiquitous environmental contaminants. In the last decades, phthalates and their metabolites have proven to be of concern, particularly in products for pregnant women or children. Moreover, many authors reported high concentrations of phthalates in soft drinks, mineral waters, wine, oil, ready-to-eat meals, and other products, as a possible consequence of their accumulation along the food production chain and their accidental release from packaging materials. However, due to their different physical and chemical properties, phthalates do not have the same human and environmental impacts and their association to several human diseases is still under debate. In this review we provide an overview of phthalate toxicity, pointing out the health and legal issues related to their occurrence in several types of food and beverage.

Wnt pathway: A mechanism worth considering in endocrine disrupting chemical action

Endocrine disrupting chemicals (EDCs) are defined as exogenous substances that can alter the development and functioning of the endocrine system. The Wnt signaling pathway is an evolutionarily conserved pathway consisting of proteins that transmit cell-to-cell receptors through cell surface receptors, regulating important aspects of cell migration, polarity, neural formation, and organogenesis, which determines the fate of the cell during embryonic development. Although the effects of EDCs have been studied in terms of many molecular mechanisms; because of its critical role in embryogenesis, the Wnt pathway is of special interest in EDC exposure. This review provides information about the effects of EDC exposure on the Wnt/β-catenin pathway focusing on studies on bisphenol A, di-(2-ethylhexyl) phthalate, diethylstilbestrol, cadmium, and 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Di(2-ethylhexyl) phthalate inhibits glutathione regeneration and dehydrogenases of the pentose phosphate pathway on human colon carcinoma cells

Phthalates, particularly di(2-ethylhexyl) phthalate (DEHP), are compounds widely used as plasticizers and have become serious global contaminants. Because of the bioaccumulation of such substances, the food chain is at risk. The food contamination by some phthalates has been linked to different side effects in experimental animals. That is why we have chosen the intestinal system's cells which represent the primary targets of these compounds to test their toxic effects. Human colon carcinoma cells (HCT 116) were chosen to elucidate whether DEHP triggers oxidative stress and apoptosis. Our results indicated that DEHP is cytotoxic; it induces the overexpression of Hsp70 protein and causes oxidative damage through the generation of free radicals leading to lipid peroxidation induction and the increase of superoxide dismutase (SOD) and catalase (CAT) activities. In addition, cell treatment with DEHP resulted in a glutathione (GSH) content decrease and a decrease in the glutathione reductase (GR) activity. As new evidence provided in this study, we demonstrated that the DEHP affected the two enzymes' activities of the oxidative phase of the pentose phosphate pathway: Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD). This leads to a decrease in the level of NADPH used by the GR to maintain the regeneration of the reduced GSH. We also demonstrated that such effects can be responsible for DEHP-induced apoptosis.

Occurrence of phthalate esters in the eastern coast of Thailand

In this work, we investigated possible contamination of phthalates in seawater and sediment around the eastern coast of Thailand in the area of Chonburi, Rayong, and Chanthaburi. The main focus was on Pradu Bay east of Map Ta Phut, a well-known industrial and economic hub in Thailand. Among six selected phthalates of interest, diethyl phthalate (DEP), and benzyl butyl phthalate (BBP) were not found in any sample, while the concentrations of dimethyl phthalate (DMP) and dioctyl phthalate (DnOP) were very low or undetectable in most samples. In December 2014, the concentration of dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) in Pradu Bay were 0.23-0.77 and 0.31-0.91 μg L^-1 in seawater, respectively and non-detected (ND)-0.80 and ND-1.65 μg g^-1 for 11 out of 20 sediment samples. DBP and DEHP were considered as the predominant congeners. A surface mapping system provided us an overview concentration distribution of DBP and DEHP congeners in seawater and sediment in Pradu Bay, showing a correlation between water and sediment and allowing a prediction of a possible point source. A comparison with the EU standard concentration limit in surface water confirmed that the phthalate concentration in this area was acceptable. However, continuous monitoring of phthalate congeners in the matrices should be done to detect a possible increase in their concentrations. To the best of our knowledge, this is the first study to determine concentrations of phthalates in seawater and sediment along the east coast of Thailand.

Di-n-butyl phthalate degrading endophytic bacterium Bacillus amyloliquefaciens subsp. strain JR20 isolated from garlic chive and its colonization in a leafy vegetable

Di-n-butyl phthalate (DBP) is one of the primary PAEs (phthalate acid esters) pollutants. DBP can be absorbed by plants and threaten human health via the food chain. Some DBP-degrading bacteria have been successfully isolated from the environment (water, soil, etc.). However, only a few DBP-degrading plant endophytes have been isolated. In this study, an endophytic bacterium, Bacillus amyloliquefaciens subsp. strain JR20, which was found capable of degrading DBP, was isolated from garlic chive. We found that strain JR20 metabolized 89.74% of DBP at a 5 mg/L concentration within 4 d in liquid mineral salts medium (MSM). The optimized conditions for maximum removal of DBP were as follows: DBP concentration, 5 mg/L; pH, 7-8; temperature, 30-40 °C. The colonization of strain JR20 significantly improved the degradation rate of DBP in the roots, stems and leaves of leafy vegetables.

Phthalic acid esters content in yoghurt with chia flour and bamboo fiber during storage time

Phthalic acid esters are plasticizers, they can migrate freely from plastic to their surroundings. They have negative health effects. European legislation sets specific migration limits for phthalic acid esters. In our study, we deal with two esters of phthalic acid, dibutylphtalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP). It was studied the effect of storage of four types of yoghurt on the concentration of phthalic acid esters. Yoghurts contained 1% chia flour, 5% chia flour, 1% bamboo fiber and 5% bamboo fiber. Yoghurts were stored in plastic cups, which contained both examined phthalic acid esters. Esters of phthalic acid were determined after 1 week of storage then after 2 weeks of storage and in the original raw material. Furthermore, the pH of the yoghurt was determined. The pH values ”‹”‹were correlated with phthalate concentrations: the correlation coefficient for DBP with a pH of -0.0265 and for DEHP with a pH of 0.3075. Mean concentrations of DEHP decreased over time, while DBP decreased for yoghurt with 1% chia flour, while in other cases they increased. The mean DBP concentrations in yoghurt were higher than the average concentrations of DEHP. Comparing the mean sample values ”‹”‹with t-test for dependent samples for yoghurt of the same type, when comparing the DBP or DEHP concentration in week 1 with the DBP or DEHP concentration at week 2, the mean values ”‹”‹were consistent. It can be noted that there was no increase in DEHP concentrations from cups to yoghurts, which was probably due to a lower concentration in cups than the DBP concentration. DBP concentrations increased in 3 of the 4 types of yoghurt. The determined pH in yoghurts did not differ significantly. Apparently a greater effect on the migration of phthalic acid esters will have in our case a different yoghurt consistency than pH. It would be appropriate to examine the effect of food density on the migration of phthalic acid esters. Likewise, it would be appropriate to examine the effect of pH but in the same food with different pH on the migration of phthalic acid esters. 

The solvent effects on dimethyl phthalate investigated by FTIR characterization, solvent parameter correlation and DFT computation

This study set out with the aim of investigating the solvent effects on dimethyl phthalate (DMP) using FTIR characterization, solvent parameter correlation and DFT calculation. DMP exposed to 17 organic solvents manifested varying shift in the carbonyl stretching vibration frequency (ν_CO). Non-alkanols induced Band I and alkanols produced Band I and Band II. Through correlating the ν_CO with the empirical solvent scales including acceptor parameter (AN), Schleyer's linear free energy parameter (G), and linear free salvation energy relationships (LSER), Band I was mainly ascribed to non-specific effects from either non-alkanols or alkanol polymers ((alkanol)_n). ν_CO of the latter indicated minor red shift and less variability compared to the former. An assumption was made and validated about the sequestering of hydroxyl group by the bulky hydrophobic chain in (alkanol)_n, creating what we refer to as "screening effects". Ab initio calculation, on the other hand, provided insights for possible hydrogen binding between DMP and (ethanol)_n or between ethanol monomers. The two components of Band I observed in inert solvents were assigned to the two CO groups adopting differentiated conformations. This in turn prompted our consideration that hydrogen binding was highly selective in favor of lowly associated (alkanol)_n and the particular CO group having relatively less steric hindrance and stronger electron-donating capacity. Band II was therefore believed to derive from hydrogen-bond interactions mainly in manner of 1:1 and 1:2 DMP-(alkanol)_n complexes.

Method development for determination of migrated phthalate acid esters from polyethylene terephthalate (PET) packaging into traditional Iranian drinking beverage (Doogh) samples: a novel approach of MSPE-GC/MS technique

In the current study, a novel magnetic solid phase extraction (MSPE) technique combined with a gas chromatography/mass spectroscopy (GC/MS) was developed to determine the phthalate ester content of bottled Doogh samples. Doogh is a yogurt-based drinking beverage, which is frequently consumed in Middle East and Balkans. It is produced by stirring yogurt in Chern separation machine and consists of substances such as water, yogurt, and salt in addition to aqueous extracts of native herbs. The magnetic multi-walled carbon nanotubes (MWCNT-Fe₃O₄) were used as adsorbents of phthalate acid esters (PAEs) due to a superior adsorption capability of hydrophobic compounds. In this context, the quantity of the extractable migrated phthalate esters (dibutyl phthalate (DBP), dimethyl phthalate (DMP), butyl benzyl phthalate (BBP), diethyl phthalate (DEP), di-N-octyl phthalate (DNOP), and bis (2-ethylhexyl) phthalate (DEHP)) from polyethylene terephthalate (PET) bottles into Doogh samples was measured. The correlation between the concentration of migrated PAEs and some factors such as the type of Doogh (gaseous and without gas), difference in brand (five brands), volume (1500 and 300 mL), and the storage time also was investigated. The migration level into Doogh samples was increased by incorporating of gas as well as increasing the volume of PET bottles. Also, with elaborating of storage time, the migration of some phthalates such as DEHP (the mean from 2419.85 ng L^-1 in the first week to 2716.15 ng L^-1 in the second month), DEP, and total phthalate was increased. However, no significant difference in concentrations of migrated phthalate esters among different examined brands was noted. Finally, the concentration of migrated PAEs from bottle into all the examined Doogh samples was below the defined standards by EPA; 6 μg/L for DEHP in drinking water. Graphical abstract ᅟ.

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

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

Adipose Tissue as a Site of Toxin Accumulation

We examine the role of adipose tissue, typically considered an energy storage site, as a potential site of toxicant accumulation. Although the production of most persistent organic pollutants (POPs) was banned years ago, these toxicants persist in the environment due to their resistance to biodegradation and widespread distribution in various environmental forms (e.g., vapor, sediment, and water). As a result, human exposure to these toxicants is inevitable. Largely due to their lipophilicity, POPs bioaccumulate in adipose tissue, resulting in greater body burdens of these environmental toxicants with obesity. POPs of major concern include polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), and polybrominated biphenyls and diphenyl ethers (PBBs/PBDEs), among other organic compounds. In this review, we (i) highlight the physical characteristics of toxicants that enable them to partition into and remain stored in adipose tissue, (ii) discuss the specific mechanisms of action by which these toxicants act to influence adipocyte function, and (iii) review associations between POP exposures and the development of obesity and diabetes. An area of controversy relates to the relative potential beneficial versus hazardous health effects of toxicant sequestration in adipose tissue. © 2017 American Physiological Society. Compr Physiol 7:1085-1135, 2017.

Food consumption survey of Shanghai adults in 2012 and its associations with phthalate metabolites in urine

BACKGROUND

Diet is considered to be a significant exposure pathway for phthalates. In this study, we assessed the associations between food consumption and urinary concentrations of phthalate metabolites among Shanghai adults.

METHODS

A cross-sectional study involving 2418 participants was conducted in the fall of 2012. Recent food consumption was assessed by a 24-h dietary recall survey, and a Food Frequency Questionnaire (FFQ) characterized long-term dietary patterns. Urinary metabolites of six phthalates were measured.

RESULTS

Both the 24-h recall survey and FFQ identified wheat, dairy, and fruits as being positively associated with the excretion of phthalate metabolites. The 24-h recall data also showed positive associations with processed meats and alcohol. We evaluated the impact of reported consumption of multiple food categories simultaneously (wheat, fruits, meats, etc.) on metabolite excretion and found that, as more food types were consumed, the number of metabolites excreted, as well as their concentrations, increased with high significance (p values<0.0001). We also evaluated the two survey instruments together. When both surveys reported consumption of fruits and dairy, the numbers of metabolites and their concentrations were significantly higher compared to when both surveys reported non-consumption, (p values<0.000001). Rice consumption was found to be negatively associated with phthalate excretion; frequent and high levels of rice consumption were found to be associated with lower excretion of metabolites.

CONCLUSION

Food consumption was associated with phthalate exposure in Shanghai adults. Both 24-h recall and FFQ identified significant associations between consumption of food types and phthalate exposure.

Methods for the Determination of Endocrine-Disrupting Phthalate Esters

Phthalates are endocrine disruptors frequently occurring in the general and industrial environment and in many industrial products. Moreover, they are also suspected of being carcinogenic, teratogenic, and mutagenic, and they show diverse toxicity profiles depending on their structures. The European Union and the United States Environmental Protection Agency (US EPA) have included many phthalates in the list of priority substances with potential endocrine-disrupting action. They are: dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBP), diethylhexyl phthalate (DEHP), di-iso-nonyl phthalate (DINP), di-iso-decyl phthalate (DIDP), di-n-decyl phthalate (DnDP), and dioctyl phthalate (DOP). There is an ever-increasing demand for new analytical methods suitable for monitoring different phthalates in various environmental, biological, and other matrices. Separation and spectrometric methods are most frequently used. However, modern electroanalytical methods can also play a useful role in this field because of their high sensitivity, reasonable selectivity, easy automation, and miniaturization, and especially low investment and running costs, which makes them suitable for large-scale monitoring. Therefore, this review outlines possibilities and limitations of various analytical methods for determination of endocrine-disruptor phthalate esters in various matrices, including somewhat neglected electroanalytical methods.

The potential reproductive effects of exposure of domestic ruminants to endocrine disrupting compounds

Chemical compounds that mimic or block some of the actions of the steroid hormone oestradiol, have created public concern primarily because of potential adverse reproductive effects in wildlife and humans. Many studies, in vivo and in vitro, have revealed abnormal reproductive function following exposure to these compounds. The number of chemicals known to have the potential to modulate endocrine functions is increasing. In contrast to humans and wildlife, the potential reproductive effects of exposure of domestic animals to endocrine disrupting compounds (EDC) have been studied little. The aim of this overview is to evaluate the possible contribution of EDC to reproductive failure in domestic ruminants.

Sources and classes of EDC are discussed as well as their structure and the modes of hormone disruption. Endocrine disrupting agents may interfere with the reproductive processes of both males and females at several points of the reproductive cycle and through a range of physiological mechanisms. Extrapolating from the results obtained with laboratory animals, the mechanisms whereby infertility in domestic ruminants might be expressed by exposure to EDC through contaminated food and drinking water are addressed.

A preliminary risk assessment is included and it is concluded that under certain circumstances there may be a significantly enhanced intake of oestrogenic hormones and EDC through sewage-contaminated water or soil-contaminated herbage. The physiological consequences for domestic ruminants of EDC ingestion, at the rates estimated, are largely unknown. However, the levels of exposure to oestrogenic hormones and phthalates in grazing ruminants are such that when studying fertility problems in high-yielding dairy cattle the impacts of exposure to endocrine disruptors via the food and drinking water cannot be neglected.

Phthalates in meat products in dependence on the fat content

The content of dibutylphthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) in samples of packages intended for thermally processed meat products and release of phthalates from packages into meat products in dependence on the fat content were observed. 80 samples of packages were analyzed, 5 of them wereselected due to exceeding the specific migration limit. The raw meat was prepared, one type with the fat content of 10% and second one with the fat content of 50%. The both types of raw meat were analyzed for the content of DBP and DEHP and packed into chosen packages.The samples of meat products were thermally processed (70 ℃, 10 min in the core), stored until the expiration date at 4 °C and gradually analyzed after 1st, 7th, 14th, 21st and 28th day of storage. Determination of phthalates was carried out by high performance liquid chromatography (HPLC) in the Zorbax Eclipse C8column and by UV detection at a wavelength of 224 mm. The phthalate content in the raw meat was under the limit of detection. According to the EU Commission Regulation no. 10/2011 the specific migration limit of products intended for the contact with food for DEHP (max. 1.5 mg.kg-1of food stimulant and DBP max. 0.3 mg.kg-1 of food stimulant), wasexceeded already after first day of storage, in case of DBP in two samples with 10% of fat and after 7th day of storage in one sample. In the samples with 50% of fat, SML was exceeded after first day of storage in four samples and in one sample after 14th day of storage. Regarding DEHP in the samples with 10% of fat SML was exceeded after 1st day of storage in one sample and after 7th day of storage also in one sample and after 21st day of storage similarly in one sample. Four samples with 50% of fat had SML exceeded in case of DEHP already after 1st day of storage. By comparison of PAE migration depending on the fat content we concluded that leaching of PAE from a package into food was 2 - 21 times higher in samples with 50% of fat than in samples with 10% of fat. 

Approaches to Children's Exposure Assessment: Case Study with Diethylhexylphthalate (DEHP)

Children's exposure assessment is a key input into epidemiology studies, risk assessment and source apportionment. The goals of this article are to describe a methodology for children's exposure assessment that can be used for these purposes and to apply the methodology to source apportionment for the case study chemical, diethylhexylphthalate (DEHP). A key feature is the comparison of total (aggregate) exposure calculated via a pathways approach to that derived from a biomonitoring approach. The 4-step methodology and its results for DEHP are: (1) Prioritization of life stages and exposure pathways, with pregnancy, breast-fed infants, and toddlers the focus of the case study and pathways selected that are relevant to these groups; (2) Estimation of pathway-specific exposures by life stage wherein diet was found to be the largest contributor for pregnant women, breast milk and mouthing behavior for the nursing infant and diet, house dust, and mouthing for toddlers; (3) Comparison of aggregate exposure by pathways vs biomonitoring-based approaches wherein good concordance was found for toddlers and pregnant women providing confidence in the exposure assessment; (4) Source apportionment in which DEHP presence in foods, children's products, consumer products and the built environment are discussed with respect to early life mouthing, house dust and dietary exposure. A potential fifth step of the method involves the calculation of exposure doses for risk assessment which is described but outside the scope for the current case study. In summary, the methodology has been used to synthesize the available information to identify key sources of early life exposure to DEHP.

Thermal, mechanical and drug release characteristics of an acrylic film using active pharmaceutical ingredient as non-traditional plasticizer

The objective of this study was to investigate thermal and mechanical properties as well as in vitro drug release of Eudragit® RL (ERL) film using chlorpheniramine maleate (CPM) as either active pharmaceutical ingredient or non-traditional plasticizer. Differential scanning calorimeter was used to measure the glass transition temperature (Tg) of 0-100% w/w CPM in ERL physical mixture. Instron testing machine was used to investigate Young's modulus, tensile stress and tensile strain (%) of ERL film containing 20-60% w/w CPM. Finally, a Franz diffusion cell was used to study drug release from ERL films obtained from four formulations, i.e. CRHP0/0, CRHP0/5, CRHP2/0 and CRHP2/5. The Tg of ERL was decreased when the weight percentage of CPM increased. The reduction of the Tg could be described by Kwei equation, indicating the interaction between CPM and ERL. Modulus and tensile stress decreased whereas tensile strain (%) increased when weight percentage of CPM increased. The change of mechanical properties was associated with the reduction of the Tg when weight percentage of CPM increased. ERL films obtained from four formulations could release the drug in no less than 10 h. Cumulative amount of drug release per unit area of ERL film containing only CPM (CRHP0/0) was lower than those obtained from the formulations containing traditional plasticizer (CRHP0/5), surfactant (CRHP2/0) or both of them (CRHP2/5). The increase of drug release was a result of the increase of drug permeability through ERL film and drug solubility based on traditional plasticizer and surfactant, respectively.

Contemporary carbon content of bis (2-ethylhexyl) phthalate in butter

The fraction of naturally produced bis (2-ethylhexyl) phthalate (DEHP), a ubiquitous plasticizer known to contaminate packaged foods, was determined for each of five 1.10 kg samples of unsalted market butter by accelerator mass spectrometry (AMS). After extraction and concentration enrichment with liquid-liquid extraction, flash column chromatography, and preparative-scale high performance liquid chromatography, each sample provided ≈ 250 μg extracts of DEHP with carbon purity ranging from 92.5 ± 1.2% (n = 3, 1σ) to 97.1 ± 0.8% (n = 3, 1σ) as measured with gas chromatography mass spectrometry (GC-MS). After corrections for method blank DEHP, co-eluting compounds, and unidentified carbon, the mean fraction of naturally produced DEHP in butter was determined to be 0.16 ± 0.12 (n = 5, 1σ). To our knowledge, this is the first report of the contemporary fraction of DEHP isolated from market butter in the U.S.

Endocrine-disrupting Chemicals: Review of Toxicological Mechanisms Using Molecular Pathway Analysis

Endocrine disruptors are known to cause harmful effects to human through various exposure routes. These chemicals mainly appear to interfere with the endocrine or hormone systems. As importantly, numerous studies have demonstrated that the accumulation of endocrine disruptors can induce fatal disorders including obesity and cancer. Using diverse biological tools, the potential molecular mechanisms related with these diseases by exposure of endocrine disruptors. Recently, pathway analysis, a bioinformatics tool, is being widely used to predict the potential mechanism or biological network of certain chemicals. In this review, we initially summarize the major molecular mechanisms involved in the induction of the above mentioned diseases by endocrine disruptors. Additionally, we provide the potential markers and signaling mechanisms discovered via pathway analysis under exposure to representative endocrine disruptors, bisphenol, diethylhexylphthalate, and nonylphenol. The review emphasizes the importance of pathway analysis using bioinformatics to finding the specific mechanisms of toxic chemicals, including endocrine disruptors.

Toxicologically relevant phthalates in food

Various phthalates have been detected in a wide range of food products such as milk, dietary products, fat-enriched food, meat, fish, sea food, beverages, grains, and vegetables as well as in breast milk. Here we present an overview on toxicologically considerable phthalate levels in food reported in the literature. The most common phthalates detected are di-(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and di-isobutyl phthalate (DiBP). Milk analyses demonstrate that background levels in unprocessed milk are usually low. However, during processing the phthalate contents may significantly increase due to migration from plastic materials in contact with food. Among dietary products fat-enriched food such as cheese and cream were identified with highest levels of DEHP. Plasticized PVC from tubes, conveyor belts, or disposable gloves used in food processing is an important source for contamination of food, especially of fatty food. Paper and cardboard packaging made from recycled fibers are another important source of contamination. In addition, gaskets used in metal lids for glass jars have been identified as possible source for the contamination of foodstuffs with phthalates. The highest concentrations of DEHP reported (>900 mg kg(-1)) were detected in food of high fat content stored in such glass jars. Beyond classical food, DEHP and DnBP were identified in human breast milk samples as the main phthalate contaminants. Phthalate monoesters and some oxidative metabolites were also quantified in breast milk.

An indirect competitive biotin-streptavidin enzyme-linked immunosorbent assay for the determination of dimethyl phthalate (DMP) in milk and milk products

After the "plasticizer event" in Taiwan, phthalic acid esters (PAEs) have been listed in "Inedible materials possibly added into food illegally" and "Commonly abused food additives." As one of the PAEs family, DMP has long been a problem of great concern due to its potential impacts on human health. In order to detect DMP with high sensitivity and specificity, a sensitive indirect competitive biotin-streptavidin enzyme-linked immunosorbent assay (BA-ELISA) has been established in this study. A high-titer rabbit polyclonal antibody (pAb-DMP) targeting DMP was obtained, and the procedures of BA-ELISA were optimized for the determination of DMP in milk and milk products. Under optimal conditions, good linearity was achieved within a range of 0.024 to 6.027 μg L(-1), with low cross-reactivity values for DMP structural analogues (lower than 10%). The median inhibitory concentration (IC50) was 0.356 μg L(-1) and the limit of detection (LOD) was 0.0082 μg L(-1). Finally, the concentrations of DMP in milk and milk products ranged from 1.03 μg kg(-1) to 7.23 μg kg(-1) by BA-ELISA. Satisfactory recoveries (90.26-112.38%) and coefficient of variation (CV) values (5.08-8.46%) were obtained. These results were consistent with those using gas chromatography-mass spectrometry (GC-MS), which further confirmed that the proposed BA-ELISA was accurate, specific, reliable and rapid for routine monitoring trace DMP residues in foodstuff, especially milk and milk products.

Occurrence, fate and effects of Di (2-ethylhexyl) Phthalate in wastewater treatment plants: a review

Phthalates, such as Di (2-ethylhexyl) Phthalate (DEHP) are compounds extensively used as plasticizer for long time around the world. Due to the extensive usage, DEHP is found in many surface waters (0.013-18.5 μg/L), wastewaters (0.716-122 μg/L), landfill leachate (88-460 μg/L), sludge (12-1250 mg/kg), soil (2-10 mg/kg). DEHP is persistent in the environment and the toxicity of the byproducts resulting from the degradation of DEHP sometime exacerbates the parent compound toxicity. Water/Wastewater treatment processes might play a key role in delivering safe, reliable supplies of water to households, industry and in safeguarding the quality of water in rivers, lakes and aquifers. This review addresses state of knowledge concerning the worldwide production, occurrence, fate and effects of DEHP in the environment. Moreover, the fate and behavior of DEHP in various treatment processes, including biological, physicochemical and advanced processes are reviewed and comparison (qualitative and quantitative) has been done between the processes. The trends and perspectives for treatment of wastewaters contaminated by DEHP are also analyzed in this review.

Exogenous hormonal regulation in breast cancer cells by phytoestrogens and endocrine disruptors

Observations on the role of ovarian hormones in breast cancer growth, as well as interest in contraception, stimulated research into the biology of estrogens. The identification of the classical receptors ERα and ERβ and the transmembrane receptor GPER and the resolution of the structure of the ligand bound to its receptor established the principal molecular mechanisms of estrogen action. The presence of estrogen-like compounds in many plants used in traditional medicine or ingested as food ingredients, phytoestrogens, as well as the estrogenic activities of many industrial pollutants and pesticides, xenoestrogens, have prompted investigations into their role in human health. Phyto- and xenoestrogens bind to the estrogen receptors with a lower affinity than the endogenous estrogens and can compete or substitute the hormone. Xenoestrogens, which accumulate in the body throughout life, are believed to increase breast cancer risk, especially in cases of prenatal and prepuberal exposure whereas the role of phytoestrogens is still a matter of debate. At present, the application of phytoestrogens appears to be limited to the treatment of post-menopausal symptoms in women where the production of endogenous estrogens has ceased. In this review we discuss chemistry, structure and classification, estrogen signaling and the consequences of the interactions of estrogens, phytoestrogens and xenoestrogens with their receptors, the complex interactions of endogenous and exogenous ligands, the evaluation of the health risks related to xenoestrogens, and the perspectives toward the synthesis of potent third generation selective estrogen receptor modulators (SERMs).

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.

Food emulsifier polysorbate 80 increases intestinal absorption of di-(2-ethylhexyl) phthalate in rats

The aim of the present research was to explore whether food emulsifier polysorbate 80 can enhance the absorption of di-(2-ethylhexyl) phthalate (DEHP) and its possible mechanism. We established the high-performance liquid chromatography (HPLC) method for detecting DEHP and its major metabolite, mono-ethylhexyl phthalate (MEHP) in rat plasma, and then examined the toxicokinetic and bioavailability of DEHP with or without polysorbate 80 in rats. The study of its mechanism to increase the absorption of phthalates demonstrated that polysorbate 80 can induce mitochondrial dysfunction in time- and concentration-dependence manners in Caco-2 cells by reducing mitochondrial membrane potential, diminishing the production of the adenosine triphosphate, and decreasing the activity of electron transport chain. Our results indicated that food emulsifier applied in relatively high concentrations in even the most frequently consumed foods can increase the absorption of DEHP, and its role may be related to the structure and function damages of mitochondria in enterocytes.

Disturbances of sperm maturation and minipuberty: is there a connection?

Male reproductive function in the general population raises an increased attention due to reports indicating declining sperm counts, increased occurrence of testicular cancer, cryptorchidism, and hypospadias. It is also hypothesized that prolonged exposure of the developing male, during both fetal and postnatal life, to exogenous estrogens could reduce Sertoli cell number and thus reduce sperm output (and sperm counts) in adult life. Fact is that infertility, which is defined as the inability to conceive after 1 year of unprotected intercourse, has a global prevalence of 9%. A male contributory factor is involved in approximately half of these cases, but most of the causes of reduced semen quality and other disturbances of male reproductive function are unknown. In the most affected men (azoospermic men) 15-20% had a prior history of cryptorchidism. The association between the cryptorchidism and infertility is one of the most studied potential causes of infertility. There are numerous studies that accentuate the importance of minipuberty for future fertility. Is it possible that a normal minipuberty ensures normal fertility despite malpositioned testes? And to move away from cryptorchidism, could impaired minipuberty be responsible for fertility problems in men who were born with both testes in their scrotal sacs?

Effect of Di(2-ethylhexyl)phthalate on Helicobacter pylori-Induced Apoptosis in AGS Cells

Plastic products are wildly used in human life. Di(2-ethylhexyl)phthalate (DEHP) is an essential additive in plastic manufacturing and is used as plasticizer for many products including plastic food packaging. DEHP is a teratogenic compound and can cause potent reproductive toxicity. DEHP can also cause liver damage, peroxisome proliferation, and carcinogenesis. DEHP is also strongly associated with peptic ulcers and gastric cancer; however, the underlying effect and mechanism of DEHP on the gastrointestinal tract are not entirely clear. The oral infection route of H. pylori parallels the major ingestion route of DEHP into the human body. Therefore, we wanted to study the effect of DEHP and H. pylori exposure on the human gastric epithelial cell line, AGS (gastric adenocarcinoma). The viability of the AGS cell line was significantly lower in 80  μ M-DEHP and H. pylori (MOI = 100 : 1) coexposure than DEHP or H. pylori alone. DEHP and H. pylori coexposure also induced caspase-3 activation, and increased Bax/Bcl-2 ratio and DNA fragmentation in AGS cells. These results indicate that DEHP can enhance H. pylori cytotoxicity and induce gastric epithelial cell apoptosis. Therefore, it is possible that DEHP and H. pylori coexposure might enhance the disruption of the gastric mucosa integrity and potentially promote the pathogenesis of gastric carcinogenesis.

Toxicological characterization of phthalic Acid

There has been growing concern about the toxicity of phthalate esters. Phthalate esters are being used widely for the production of perfume, nail varnish, hairsprays and other personal/cosmetic uses. Recently, exposure to phthalates has been assessed by analyzing urine for their metabolites. The parent phthalate is rapidly metabolized to its monoester (the active metabolite) and also glucuronidated, then excreted. The objective of this study is to evaluate the toxicity of phthalic acid (PA), which is the final common metabolic form of phthalic acid esters (PAEs). The individual PA isomers are extensively employed in the synthesis of synthetic agents, for example isophthalic acid (IPA), and terephthalic acid (TPA), which have very broad applications in the preparation of phthalate ester plasticizers and components of polyester fiber, film and fabricated items. There is a broad potential for exposure by industrial workers during the manufacturing process and by the general public (via vehicle exhausts, consumer products, etc). This review suggests that PA shows in vitro and in vivo toxicity (mutagenicity, developmental toxicity, reproductive toxicity, etc.). In addition, PA seems to be a useful biomarker for multiple exposure to PAEs in humans.

Short- and long-term temporal changes in soil concentrations of selected endocrine disrupting compounds (EDCs) following single or multiple applications of sewage sludge to pastures

Temporal changes in soil burdens of selected endocrine disrupting compounds were determined following application to pasture of either sewage sludge or inorganic fertilizer. Soil polycyclic aromatic hydrocarbon and polychlorinated biphenyl concentrations were not altered. Changes in concentrations of diethylhexyl phthalate (DEHP) and PBDEs 47 and 99 differed with season but concentrations remained elevated for more than three weeks after application, when grazing animals are normally excluded from pasture. It is concluded that single applications of sewage sludge can increase soil concentrations of some, but not all classes of EDCs, possibly to concentrations sufficient to exert biological effects when different chemicals act in combination, but patterns of change depend on season and soil temperature. Analysis of soil from pasture subjected to repeated sludge applications, over 13 years, provided preliminary evidence of greater increases in soil burdens of all of the EDC groups measured, including all of the PBDE congeners measured.

Oxidative stress and phthalate-induced down-regulation of steroidogenesis in MA-10 Leydig cells

Previous studies have shown that phthalate exposure can suppress steroidogenesis. However, the affected components of the steroidogenic pathway, and the mechanisms involved, remain uncertain. We show that incubating MA-10 Leydig cells with mono-(2-ethylhexyl) phthalate (MEHP) resulted in reductions in luteinizing hormone (LH)-stimulated cAMP and progesterone productions. cAMP did not decrease in response to MEHP when the cells were incubated with cholera toxin or forskolin. Incubation of MEHP-treated cells with dibutyryl-cAMP, 22-hydroxycholesterol or pregnenolone inhibited the reductions in progesterone. Increased levels of reactive oxygen species (ROS) occurred in response to MEHP. In cells in which intracellular glutathione was depleted by buthionine sulfoximine pretreatment, the increases in ROS and decreases in progesterone in response to MEHP treatment were exacerbated. These results indicate that MEHP inhibits MA-10 Leydig cell steroidogenesis by targeting LH-stimulated cAMP production and cholesterol transport, and that a likely mechanism by which MEHP acts is through increased oxidative stress.