Determination of phthalate monoesters in human milk, consumer milk, and infant formula by tandem mass spectrometry (LC-MS-MS)

Mechanistic screening of reproductive toxicity in a novel 3D testicular co-culture model shows significant impairments following exposure to low-dibutyl phthalate concentrations

To improve the mechanistic screening of reproductive toxicants in  chemical-risk assessment and drug development, we have developed a three-dimensional (3D) heterogenous testicular co-culture model from neonatal mice. Di-n-butyl phthalate (DBP), an environmental contaminant that can affect reproductive health negatively, was used as a model compound to illustrate the utility of the in vitro model. The cells were treated with DBP (1 nM to 100 µM) for 7 days. Automated high-content imaging confirmed the presence of cell-specific markers of Leydig cells (CYP11A1 +), Sertoli cells (SOX9 +), and germ cells (DAZL +). Steroidogenic activity of Leydig cells was demonstrated by analyzing testosterone levels in the culture medium. DBP induced a concentration-dependent reduction in testosterone levels and decreased the number of Leydig cells compared to vehicle control. The levels of steroidogenic regulator StAR and the steroidogenic enzyme CYP11A1 were decreased already at the lowest DBP concentration (1 nM), demonstrating upstream effects in the testosterone biosynthesis pathway. Furthermore, exposure to 10 nM DBP decreased the levels of the germ cell-specific RNA binding protein DAZL, central for the spermatogenesis. The 3D model also captured the development of the Sertoli cell junction proteins, N-cadherin and Zonula occludens protein 1 (ZO-1), critical for the blood-testis barrier. However, DBP exposure did not significantly alter the cadherin and ZO-1 levels. Altogether, this 3D in vitro system models testicular cellular signaling and function, making it a powerful tool for mechanistic screening of developmental testicular toxicity. This can open a new avenue for high throughput screening of chemically-induced reproductive toxicity during sensitive developmental phases.

Short-term exposure to di(2-ethylhexyl)phthalate may disrupt hepatic lipid metabolism through modulating the oxidative stress in male adolescent rats

Di(2-ethylhexyl)phthalate (DEHP) is commonly used to increase the flexibility of plastics. In our previous study, DEHP may increase hepatic lipid accumulation through modulating of acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) expression. Nevertheless, it is hard to understand the association between DEHP and DGAT1 in the liver because only one dosage of DEHP was used. Thus, this study performed to investigate the role of DGAT1 on hepatic lipid metabolism after various dosages of DEHP exposure. Four-week-old male Sprague-Dawley rats (n = 5/group) were administered corn oil (vehicle) or DEHP (0.75, 7.5, 15, or 150 mg/kg/day) once daily for seven days. DEHP 150 mg/kg/day treated group increased body weight gain and relative liver weight compared to the control (P = 0.044 and P = 0.049, respectively). In histological observation, elevation of hepatic lipid accumulation was observed in all DEHP-treated groups, except DEHP 150 mg/kg/day, compared to that in the control (all P < 0.001). Portal inflammatory infiltration and acidophilic bodies were observed in the liver at DEHP 7.5 mg/kg/day and above treated groups. In addition, malondiadehyde levels, a marker of lipid peroxidation, in the liver were increased in DEHP 7.5, 15 and 150 mg/kg/day compared to the control (P = 0.017, P = 0.001, and P = 0.002, respectively). The expression of Dgat1 in the liver was significantly increased in DEHP 7.5, 15 and 150 mg/kg/day compared to the control group (P = 0.019, P = 0.002, and P < 0.001, respectively); however, there were no significant changes in the protein levels. Therefore, excessive oxidative stress caused by DEHP may induce liver damage such as inflammation rather than hepatic lipid accumulation by regulating DGAT1 transcription.

Phthalate metabolites in breast milk from mothers in Southern China: Occurrence, temporal trends, daily intake, and risk assessment

The extensive production and use of phthalates means that these compounds are now ubiquitous in the environment and various biota, which raises concerns about potential harmful health effects. In this study, phthalate metabolites (mPAEs) were measured in breast milk (n = 100) collected from mothers of southern China between 2014 - 2022. Of the nine target mPAEs, five were detected in all of the samples, including mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono-(2-ethylhexyl) phthalate (MEHP). The total levels of mPAEs in breast milk ranged from 4.76 to 51.6 ng/mL, with MiBP and MnBP being the predominant isomers (MiBP + MnBP > 48.3%). Increasing trends were observed in MMP (5.7%/year) and MEHP (7.1%/year) levels during the study period, while a decreasing trend were observed in MiBP (-6.6%/year); no clear temporal trends were found for the other metabolites and total mPAE levels. The results indicate that exposure to phthalates is still prevalent in southern China. Breastfeeding was found to contribute to estimated daily phthalate intakes of 0.383-6.95 μg/kg-bw/day, suggesting insignificant health risks to infants based on dietary exposure. However, the increasing exposure to MMP and MEHP calls for more research into the possible sources and potential risks.

Estimation of exposure to phthalate esters from consumption of powdered infant formula sampled in Turkey

Phthalate esters (PAEs) adversely affect the human endocrine and reproductive systems. These chemical toxic compounds are used as plasticizers, in particular to improve the mechanical properties of different food packing materials. Daily food consumption is the predominant source of exposure for PAEs, especially for infants. In this study, residue profiles and levels for eight PAEs were determined in 30 infant (stage I, II and special A and B) formulas of 12 brands in Turkey and health risk assessments were performed. The average level of PAEs were different for each formula group and packing type except for BBP (p < 0.01). The highest average mean level of PAEs was detected in paperboard type packing, while the lowest average mean level of PAEs was detected in metal can type packing. The highest average level of PAEs detected was DEHP in special formulas (22.1 ng g^-1). The average hazard quotient (HQ) value was calculated as 8.43 × 10^-5-8.94 × 10^-5 for BBP, 1.49 × 10^-3-1.58 × 10^-3 for DBP, 2.06 × 10^-2-2.18 × 10^-2 for DEHP, and 7.21 × 10^-4-7.65 × 10^-4 for DINP. The average HI values were calculated as 2.29 × 10^-2 for 0-6 months old infants, 2.39 × 10^-2 for 6-12 months old infants, and 2.43 × 10^-2 for 12-36 months old infants. These calculated results show that commercial infant formulas were a source of exposure to PAEs but did not present a significant health risk.

Structural basis of the activation of PPARγ by the plasticizer metabolites MEHP and MINCH

Di-2-ethylhexyl phthalate (DEHP) and its substitute 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) are widely used as plasticizers but may have adverse health effects. Via hydrolysis of one of the two ester bonds in the human body, DEHP and DINCH form the monoesters MEHP and MINCH, respectively. Previous studies demonstrated binding of these metabolites to PPARγ and the induction of adipogenesis via this pathway. Detailed structural understanding of how these metabolites interact with PPARγ and thereby affect human health is lacking until now. We therefore characterized the binding modes of MINCH and MEHP to the ligand binding domain of PPARγ by X-ray crystallography and molecular dynamics (MD) simulations. Both compounds bind to the activating function-2 (AF-2) binding site via an interaction of the free carboxylates with the histidines 323 and 449, tyrosine 473 and serine 289. The alkyl chains form hydrophobic interactions with the tunnel next to cysteine 285. These binding modes are generally stable as demonstrated by the MD simulations and they resemble the complexation of fatty acids and their metabolites to the AF-2 site of PPARγ. Similar to the situation for these natural PPARγ agonists, the interaction of the free carboxylate groups of MEHP and MINCH with tyrosine 473 and surrounding residues stabilizes the AF-2 helix in the upward conformation. This state promotes binding of coactivator proteins and thus formation of the active complex for transcription of the specific target genes. Moreover, a comparison of the residues involved in binding of the plasticizer metabolites in vertebrate PPARγ orthologs shows that these compounds likely have similar effects in other species.

Characterization of different contaminants and current knowledge for defining chemical mixtures in human milk: A review

Hundreds of xenobiotics, with very diverse origins, have been detected in human milk, including contaminants of emerging concern, personal care products and other current-use substances reflecting lifestyle. The routes of exposure to these chemicals include dermal absorption, ingestion and inhalation. Specific families of chemicals are dominant among human milk monitoring studies (e.g., organochlorine pesticides, bisphenol A, dioxins), even though other understudied families may be equally toxicologically relevant (e.g., food-processing chemicals, current-use plasticizers and flame retardants, mycotoxins). Importantly, the lack of reliable human milk monitoring data for some individual chemicals and, especially, for complex mixtures, is a major factor hindering risk assessment. Non-targeted screening can be used as an effective tool to identify unknown contaminants of concern in human milk. This approach, in combination with novel methods to conduct risk assessments on the chemical mixtures detected in human milk, will assist in elucidating exposures that may have adverse effects on the development of breastfeeding infants.

Gestational and lactational exposure to the emergent alternative plasticizer 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) impairs lipid metabolism to a greater extent than the commonly used Di(2-ethylhexyl) phthalate (DEHP) in the adult rat mammary gland

Due to their endocrine disruption properties, phthalate plasticizers such as di(2-ethylhexyl) phthalate (DEHP) can affect the hormone-dependent development of the mammary gland. Over the past few years, DEHP has been partially replaced by 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) which also have potential endocrine disrupting properties. The goal of the present study is to understand the impact of a gestational and lactational exposure to DEHP and DINCH on mammary gland development using Sprague-Dawley rats. Both plasticizers altered the adipocytes of the mammary gland fat pad of adult progeny, as demonstrated by a decrease in their size, folding of their membrane and modulations of the lipid profiles. DEHP treatments decreased the expression of Rxrα and Scd1 at the low and high dose, respectively, but did not affect any of the other genes studied. DINCH modulation of lipid metabolism could be observed at puberty by a decreased expression of genes implicated in triglyceride synthesis, lipid transport and lipolysis, but by an increased expression of genes of the β-oxidation pathway and of genes involved in lipid storage and fatty acid synthesis at adulthood, compared to control and DEHP-treated rats. A strong upregulation of different inflammatory markers was observed following DINCH exposure only. Together, our results indicate that a gestational and lactational exposure to DINCH has earlier and more significant effects on lipid homeostasis, adipogenesis and the inflammatory state of the adult mammary gland than DEHP exposure. The long-term consequence of these effects on mammary gland health remained to be determined.

Phthalate metabolites in paired human serum and whole blood

Presence of phthalate metabolites (PMs) in human serum has been well documented. However, the distribution pattern of PMs in different human blood matrixes remains not well known. To investigate this, paired serum and whole blood samples were collected from 145 adults (76 males and 69 females) in Quzhou, China, and analyzed for nine PMs in this study. All PMs had high detection frequencies (> 70%) in human serum and whole blood, except mono benzyl phthalate. Total concentrations of detected PMs in serum and whole blood were 0.70-61 ng/mL (mean 12 ng/mL) and 1.6-33 ng/mL (7.5 ng/mL), respectively. Mono methyl phthalate (MMP), mono (2-ethylhexyl) phthalate, and mono butyl phthalate were consistently the predominant PMs in human serum and whole blood, with the mean concentrations of 3.4 and 2.0 ng/mL, 3.3 and 2.1 ng/mL, and 2.8 and 1.8 ng/mL, respectively. Females had higher mean serum concentrations of PMs, except MBP, than males. Youngest age group (20-30 years) consistently had the lowest mean whole blood levels of all PMs. For the first time, the distribution pattern of PMs in human blood was evaluated based on the calculated partitioning coefficient (K_p) between serum and whole blood. MMP had the highest mean K_p value (1.6; 10th-90th percentile: 1.0-2.2), while mono (2-ethyl-5-oxohexyl) phthalate had the lowest mean K_p value (0.63; 10th-90th percentile: 0.25-1.3). These results help better understand the occurrence of PMs in human blood.

Phthalate metabolites: Characterization, toxicities, global distribution, and exposure assessment

Phthalates are plasticizers in various products and regarded as endocrine disruptors due to their anti-androgen effects. Environmental occurrence and toxicities of parent phthalates have been widely reported, while the current state of knowledge on their metabolites is rarely summarized. Based on the available literature, the present review mainly aims to 1) characterize the potential metabolites of phthalates (mPAEs) using the pharmacokinetics evidences acquired via animal or human models; 2) examine the molecular and cellular mechanism involved in toxicity for mPAEs; 3) investigate the exposure levels of mPAEs in different human specimens (e.g., urine, blood, seminal fluid, breast milk, amniotic fluid and others) across the globe; 4) discuss the models and related parameters for phthalate exposure assessment. We suggest there is subtle difference in toxic mechanisms for mPAEs compared to their parent phthalates due to their alternative chemical structures. Human monitoring studies performed in Asia, America and Europe have provided the population exposure baseline levels for typical phthalates in different regions. Urine is the preferred matrix than other specimens for phthalate exposure study. Among ten urinary mPAEs, the largest proportions of di-(2-ethylhexyl) phthalate (DEHP) metabolites (40%), monoethyl phthalate (mEP) (43%) and DEHP metabolites/mEP (both 29%) were observed in Asia, America and Europe respectively, and mono-5-carboxy-2-ethypentyl phthalate was the most abundant compounds among DEHP metabolites. Daily intakes of phthalates can be accurately calculated via urinary mPAEs if the proper exposure parameters were determined. Further work should focus on combining epidemiological and biological evidences to establish links between phthalates exposure and biological phenotypes. More accurate molar fractions (F_UE) of the urinary excreted monoester related to the ingested diesters should be collected in epidemiological or pharmacokinetic studies for different population.

The Impairment of Thyroid Hormones Homeostasis after Short-Term Exposure to Di(2-ethylhexyl)phthalate in Adolescent Male Rats

Di(2-ethylhexyl)phthalate (DEHP) could induce metabolic disorders through interfering with thyroid homeostasis. Therefore, we evaluated the effects of short term to environmental relevant doses of DEHP on thyroid hormones. Four week old Sprague-Dawley (SD) rats were treated with vehicle (corn oil), and DEHP 0.75, 7.5, and 150 mg/kg/day. The rats were treated with once daily by oral gavage and were sacrificed with after 1 week. They were measured body weight and relative thyroid weight, serum thyroid hormones and histological changes of thyroid. There was no difference in body weight between the control and DEHP exposed rats. Relative thyroid weight in DEHP 150 mg/kg/day treated group was significantly lower than control. Serum thyroxine levels was decreased in rats exposed to 0.75 and 150 mg/kg/day DEHP. No histological changes were observed in the thyroid of rats administered DEHP compared to control. Exposure to DEHP at environmental relevant levels, even short-term exposure, can cause hypothyroidism in adolescent rats even the exposure period is relative short.

The effects of phthalate ester exposure on human health: A review

Phthalate esters (PAEs) are one of the most widely used plasticizers in polymer products and humans are increasingly exposed to them. The constant exposure to PAEs-contained products has raised some concerns against human health. Thus, the impacts of PAEs and their metabolites on human health require a comprehensive study for a better understanding of the associated risks. Here, we attempt to review eight main health effects of PAE exposure according to the most up-to-date studies. We found that epidemiological studies demonstrated a consistent association between PAE exposure (especially DEHP and its metabolites) and a decrease in sperm quality in males and symptom development of ADHD in children. Overall, we found insufficient evidence and lack of consistency of the association between PAE exposure and cardiovascular diseases (hypertension, atherosclerosis, and CHD), thyroid diseases, respiratory diseases, diabetes, obesity, kidney diseases, intelligence performance in children, and other reproductive system-related diseases (anogenital distance, girl precocious puberty, and endometriosis). Future studies (longitudinal and follow-up investigations) need to thoroughly perform in large-scale populations to yield more consistent and powerful results and increase the precision of the association as well as enhance the overall understanding of potential human health risks of PAEs in long-term exposure.

Prenatal exposure to phthalate esters and its impact on child development

Endocrine disruptive chemicals (EDCs) cause adverse health effects through interaction with endocrine systems. They are classified by chemical structure, effects on specific endocrine systems, their bioaccumulation and/or persistence in the environment, and/or clinically observable effects. In industrial nations, people are exposed to complex mixtures of many different substances all of which may have multiple and deleterious effects upon the individual. The clinical importance of epigenetic changes caused by the action of EDCs during vulnerable phases of development is currently unclear but of particular relevance. Epidemiological studies are criticized because reproducibility is not always guaranteed. Nevertheless, they remain the method of choice for the development and analysis of suitable model systems. Positive associations, despite of sometimes conflicting results, are the key in the selection of factors that can then be analyzed in model systems in an unbiased way. This article reports EDC-caused effects in the fields of growth and metabolism, neurocognitive development and sexual development and reproduction focusing mainly on phthalates and their metabolites. However, research will have to focus on the interactions of different EDCs and their consequences of prenatal and early life exposure.

In vitro and in silico investigations of endocrine disruption induced by metabolites of plasticizers through glucocorticoid receptor

The endocrine disruptive capability of plasticizers to activate nuclear receptors has attracted great interest. This study is aimed to assess the potential glucocorticoid effects of metabolites of plasticizers. The effects of metabolites of plasticizers on the transcriptional activity of glucocorticoid receptor (GR) were investigated using reporter gene assays. All of them failed to exhibit agonistic/antagonistic effects on GR. However, a combination of dexamethasone and monobutyl phthalate (MBP) could synergistically activate GR. MBP combined with dexamethasone also enhanced GR nuclear translocation by Western blot, while mifepristone restrained GR cytoplasmic-to-nuclear translocation. MBP co-treated with dexamethasone resulted in synergistic induction of PEPCK and MKP-1 gene expression by real-time PCR and PEPCK protein level by Western blot. Furthermore, the carboxyl and ester groups of MBP have influences on the charge distribution of MBP, leading to change of electrostatic interactions between MBP and GR by calculations on electronic properties. Both hydrophobic and hydrogen bonding interactions play a crucial role in the stabilization between MBP and GR conducted by molecular docking and dynamics simulation. This work confirms that GR could remain stable upon binding to MBP. In conclusion, dexamethasone and MBP could synergistically activate GR, resulting in synergetic enhancement of subsequent GR-mediated endocrine disrupting effect.

Analysis of Polycyclic Aromatic Hydrocarbons and Phthalate Esters in Soil and Food Grains from the Balkan Peninsula: Implication on DNA Adduct Formation by Aristolochic Acid I and Balkan Endemic Nephropathy

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial nephropathy affecting residents of rural farming areas in many Balkan countries. Although it is generally believed that BEN is an environmental disease caused by multiple geochemical factors with much attention on aristolochic acids (AAs), its etiology remains controversial. In this study, we tested the hypothesis that environmental contamination and subsequent food contamination by polycyclic aromatic hydrocarbons (PAHs) and phthalate esters are AA toxicity factors and important to BEN development. We identified significantly higher concentrations of phenanthrene, anthracene, diethyl phthalate (DEP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP) in both maize and wheat grain samples collected from endemic villages than from nonendemic villages. Other PAHs and phthalate esters were also detected at higher concentrations in the soil samples from endemic villages. Subsequent genotoxicity testing of cultured human kidney cells showed an alarming phenomenon that phenanthrene, DEP, BBP, and DBP can interact synergistically with AAs to form elevated levels of AA-DNA adducts, which are associated with both the nephrotoxicity and carcinogenicity of AAs, further increasing their disease risks. This study provides direct evidence that prolonged coexposure to these environmental contaminants via dietary intake may lead to greater toxicity and accelerated development of BEN.

An efficient and general method for the synthesis of stable isotope deuterium labeled phthalate esters

An efficient and general synthetic route of deuterium-labeled phthalate esters is described with high isotopic enrichment and excellent chemical purities using inexpensive and readily available o-xylene-D₁₀ as labeled starting material. The structures and isotope-abundance were confirmed via ¹ H NMR and mass spectrometry. These deuterium labeled phthalate esters can be used as analytical reference standards for the detection of plasticizer residues in soil, water, food, plastic products, etc.

Perinatal Exposure to Phthalates: From Endocrine to Neurodevelopment Effects

Phthalates, as other endocrine disrupting chemicals (EDCs), may alter the homeostasis and the action of hormones and signaling molecules, causing adverse health outcomes. This is true especially for infants, who are both more exposed and sensitive to their effects. Phthalates are particularly harmful when the exposure occurs during certain critical temporal windows of the development, such as the prenatal and the early postnatal phases. Phthalates may also interfere with the neuroendocrine systems (e.g., thyroid hormone signaling or metabolism), causing disruption of neuronal differentiation and maturation, increasing the risk of behavioral and cognitive disorders (ADHD and autistic behaviors, reduced mental, psychomotor, and IQ development, and emotional problems). Despite more studies being needed to better understand the role of these substances, plenty of evidence suggests the impact of phthalates on the neuroendocrine system development and function. This review aims to update the knowledge on the neuroendocrine consequences of neonatal and perinatal exposure to phthalates.

Effects of phthalates on the functions and fertility of mouse spermatozoa

Phthalates are common environmental pollutants that are presumed to negatively impact male fertility including animals and humans. Particularly, these potential xenoestrogens may alter male fertility by binding to specific sperm receptors. Although several studies have characterized the toxic effects of single phthalates, epidemiological studies indicate that humans are typically exposed to phthalate mixtures. Here, we tested an environmental-related phthalate combination composed of 21 % di(2-ethylhexyl) phthalate, 15 % diisononyl phthalate, 8% diisobutyl phthalate, 15 % dibutyl phthalate, 35 % diethyl phthalate, and 5% benzylbutyl phthalate. Specifically, the effects of short-term exposure (90 min) to various concentrations (1, 10, 100, and 500 μg/mL) of this phthalate mixture on several important sperm processes, oocyte fertilization, and embryo production were assessed. All phthalate concentrations significantly decreased sperm motility and hyperactivity by compromising the sperm's ability to generate ATP. Additionally, short-term phthalate exposure (>10 μg/mL) also induced abnormal capacitation and the acrosome reaction by upregulating protein tyrosine phosphorylation via a protein kinase-A-dependent pathway. Furthermore, phthalate exposure (particularly at doses exceeding 10 μg/mL) significantly affected fertilization and early embryonic development. Together, our findings indicate that the studied phthalate mixtures adversely affected sperm motility, capacitation, and acrosome reaction, which resulted in poor fertilization rates and repressed embryonic development. Moreover, the lowest-observed-adverse-effect dose of the phthalate mixture tested can be assumed to be < 1 μg/mL in vitro.

Comparative uptake, translocation and subcellular distribution of phthalate esters and their primary monoester metabolites in Chinese cabbage (Brassica rapa var. chinensis)

Phthalates esters (PAEs) are ubiquitous contaminants in terrestrial system and PAEs can be degraded to monoester metabolites (mPAEs) both in soil and plants, which have equal or even greater biological activity compared to their parent compounds. Until now, little is known about the comparative uptake and translocation of PAEs and mPAEs in plants. In the present study, the uptake and translocation of two commonly used plasticizers, di-n-butyl phthalate (DnBP) and di-(2-ethylhexyl) phthalate (DEHP), and the corresponding mPAEs, mono-n-butyl phthalate (MnBP) and mono-(2-ethylhexyl) phthalate (MEHP) by Chinese cabbage (Brassica rapa var. chinensis) were examined using hydroponic experiment. Significantly lower bioconcentration factors (BCFs) of mPAEs compared to the corresponding PAEs were observed. This is likely due to the great solubility and electrical repulsion from cell membrane to mPAE anions. Comparatively low translocation factors (TFs) of MnBP (7.76 ± 0.49) were observed compared to DnBP (10.33 ± 2.83); while the TFs of MEHP (0.18 ± 0.08) were significantly greater than that of DEHP (0.05 ± 0.02). The hydrophilic mPAEs are prone to concentrate in cell water-soluble components, and DnBP was relatively uniformly distributed in cell wall and cell water-soluble components; while the more hydrophobic DEHP was mainly associated with root cell wall. The formation of mPAEs occurred mainly in the above-ground tissues in the PAEs spiked treatment, and cell water-soluble compartment was the main location for PAEs metabolism. The high metabolite/parent ratios in Chinese cabbage indicate that more concern should be directed towards metabolites associated with plants via direct uptake and plant metabolism.

Phthalate esters and dexamethasone synergistically activate glucocorticoid receptor

This study was conducted to determine the endocrine-disrupting effects of phthalate esters (PAEs) on the glucocorticoid receptor (GR) signaling. Potential (anti)glucocorticoid activities of six typical PAEs including di (2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), diethyl phthalate (DEP) and dimethyl phthalate (DMP) were evaluated on human GR using cell viability assessment, reporter gene expression analysis, mRNA analysis, and molecular docking and simulation. For all tested chemicals, co-treatment of DEHP and DINP with dexamethasone (DEX) exhibited a synergistic effect on GR transactivity in the reporter assays. Such co-treatment also synergistically enhanced DEX-induced upregulation of GR mediated gene (PEPCK, FAS and MKP-1) mRNA expression in HepG2 cells and A549 cells. Molecular docking and dynamics simulations showed that hydrophobic interactions may stabilize the binding between molecules and GR. In summary, DEHP and DINP may be involved in synergistic effects via human GR, which highlight the potential endocrine-disrupting activities of PAEs as contaminants.

Combination of magnetic solid-phase extraction and HPLC-UV for simultaneous determination of four phthalate esters in plastic bottled juice

A magnetic o-hydroxyazobenzene (M-HAzo) porous organic polymer was facilely prepared by a green azo coupling reaction in aqueous solution. The prepared M-HAzo was applied as a new adsorbent for the first time to pre-concentrate phthalate esters (PAEs) from plastic bottled juice, followed by their determination with high performance liquid chromatography-ultraviolet detection. The effects of various parameters, i.e., the mass ratio of the Fe₃O₄@SiO₂ to HAzo, extraction time, ionic strength, pH of the sample, desorption conditions were optimized. Under the optimized conditions, the M-HAzo based method exhibited good performance in terms of linear range (0.3-50.0 μg L^-1), detection limit (0.08-0.50 μg L^-1), accuracy (recovery of 78.0-115.0%) and repeatability (relative standard deviation of 2.9-7.8%). This work provides a sensitive method for analysis of PAEs at trace levels in drinks, which is featured with high sensitivity, simple operation and environmentally-friendly merit and will have a promising potential in analysis of other organic pollutants.

Exposure to an environmentally relevant phthalate mixture during prostate development induces microRNA upregulation and transcriptome modulation in rats

Environmental exposure to phthalates during intrauterine development might increase susceptibility to neoplasms in reproductive organs such as the prostate. Although studies have suggested an increase in prostatic lesions in adult animals submitted to perinatal exposure to phthalates, the molecular pathways underlying these alterations remain unclear. Genome-wide levels of mRNAs and miRNAs were monitored with RNA-seq to determine if perinatal exposure to a phthalate mixture in pregnant rats is capable of modifying gene expression expression during prostate development of the filial generation. The mixture contains diethyl-phthalate, di-(2-ethylhexyl)-phthalate, dibutyl-phthalate, di-isononyl-phthalate, di-isobutyl-phthalate, and benzylbutyl-phthalate. Pregnant females were divided into 4 groups and orally dosed daily from GD10 to PND21 with corn oil (Control:C) or the phthalate mixture at three doses (20 μg/kg/d:T1; 200 μg/kg/d:T2; 200 mg/kg/d:T3). The phthalate mixture decreased anogenital distance, prostate weight and decreased testosterone level at the lowest exposure dose at PND22. The mixture also increased inflammatory foci and focal hyperplasia incidence at PND120. miR-184 was upregulated in all treated groups in relation to control and miR-141-3p was only upregulated at the lowest dose. In addition, 120 genes were deregulated at the lowest dose with several of these genes related to developmental, differentiation and oncogenesis. The data indicate that phthalate exposure at lower doses can cause greater gene expression modulation as well as other downstream phenotypes than exposure at higher doses. A significant fraction of the downregulated genes were predicted to be targets of miR-141-3p and miR-184, both of which were induced at the lower exposure doses.

A Review of Biomonitoring of Phthalate Exposures

Phthalates (diesters of phthalic acid) are widely used as plasticizers and additives in many consumer products. Laboratory animal studies have reported the endocrine-disrupting and reproductive effects of phthalates, and human exposure to this class of chemicals is a concern. Several phthalates have been recognized as substances of high concern. Human exposure to phthalates occurs mainly via dietary sources, dermal absorption, and air inhalation. Phthalates are excreted as conjugated monoesters in urine, and some phthalates, such as di-2-ethylhexyl phthalate (DEHP), undergo secondary metabolism, including oxidative transformation, prior to urinary excretion. The occurrence of phthalates and their metabolites in urine, serum, breast milk, and semen has been widely reported. Urine has been the preferred matrix in human biomonitoring studies, and concentrations on the order of several tens to hundreds of nanograms per milliliter have been reported for several phthalate metabolites. Metabolites of diethyl phthalate (DEP), dibutyl- (DBP) and diisobutyl- (DiBP) phthalates, and DEHP were the most abundant compounds measured in urine. Temporal trends in phthalate exposures varied among countries. In the United States (US), DEHP exposure has declined since 2005, whereas DiNP exposure has increased. In China, DEHP exposure has increased since 2000. For many phthalates, exposures in children are higher than those in adults. Human epidemiological studies have shown a significant association between phthalate exposures and adverse reproductive outcomes in women and men, type II diabetes and insulin resistance, overweight/obesity, allergy, and asthma. This review compiles biomonitoring studies of phthalates and exposure doses to assess health risks from phthalate exposures in populations across the globe.

Phthalates affect the in vitro expansion of human hematopoietic stem cell

cell/mL, whereas the cultures exposed to DBP, BBP and DEHP showed a reduction from 23 to 81%, 17 to 69% and 15 to 93.5%, respectively. DEP did not affect the total cell expansion. The most significant decrease on total cell expansion was observed at 0.1 μg/mL DBP, 100 μg/mL BBP and 10 μg/mL DEHP (p < 0.05). Additionally, the effect of these compounds on the expansion of hematopoietic progenitors was analyzed by clonogenic assays as colony forming units (CFU). The CFU decreased considerably compared with respect to the control cultures. The reduction was 74.6 and 99.1% at 10 and 100 μg/mL DBP respectively, whereas 100 μg/mL BBP and 100 μg/mL DEHP reduced the CFU expansion in 97.1% and 81%, respectively. Cultures exposed to DEP did not show significant differences. The results demonstrate the toxicity of DBP, BBP and DEHP on the human hematopoietic stem cells.

Nine phthalate metabolites in human urine for the comparison of health risk between population groups with different water consumptions

Phthalates are a group of high production volume chemicals widely detected in environment matrix and human specimens. Potential health risks due to the prevalence of their exposure through water consumption and the endocrine-disrupting activities have become an important issue. This work aims to compare the distributions of phthalate levels and potential health risks caused by phthalate exposure among three groups of participants ingesting different types of water. Here, a method with good performance was applied for the analysis of nine common phthalate metabolites in 125 human urine samples collected from Wuhan women. Seven analytes (mono‑ethyl, mono‑benzyl, mono‑n‑butyl, mono‑(2‑ethylhexyl), mono‑(2‑ethyl‑5‑oxohexyl), mono‑(2‑ethyl‑5‑hydroxyhexyl), and mono‑(2‑ethyl‑5‑carboxypentyl) phthalate) were detected in over 80% of the samples. By measuring urinary concentrations of phthalate monoesters, the exposure levels of respective parent phthalates, exposure patterns, the estimated daily intakes and accumulative risk assessments were investigated in three groups of participants consuming water from different sources (bottled water, filtered water and boiled tap water). The results showed that the exposure patterns of phthalates varied among the population groups with different water intakes, and the health risk was higher for people ingesting the boiled tap water than that of the groups consuming bottled water (purified water) and filtered water with filter cartridge containing activated carbon.

Determination of Five Sex Hormones in Urine Samples for Early Evaluation of Male Reproductive Toxicity Induced by Phthalate Esters in Rats

In this work, male rats were exposed to multiple phthalate esters (MIXPs) in a long-term low-dose model for the early evaluation of reproductive toxicity. An ananlysis method with better sensitivity, accuracy and precision was established to determine the five sex hormones (androstenedione, testosterone, dehydroepiandrosterone, dihydrotestosterone, and estrone) in collected urine samples. The results showed that all the analytes in the MIXPs treated group changed in a time-dependent manner. Specifically, estrone significantly decreased from the 30th day and the other four changed from the 30th day and then significantly increased on the 60th day, while no obvious changes were found in the control group. Therefore, a possible way was provided for the early evaluation of male reproductive toxicity induced by Phthalate esters (PEs) . The reliability of judgment was improved by observing the changes of five target hormones simultaneously. Furthermore, good compliance was predicted for the practical application due to the noninvasive and convenient urine sample collection.

Temporal Trends of Urinary Phthalate Concentrations in Two Populations: Effects of REACH Authorization after Five Years

Phthalates are widely used in the industrial manufacture of many products. Some phthalates have shown reproductive toxicity in humans, acting as endocrine disruptors, so they were included in the authorization process defined in Reg. CE 1907/2006 (REACH). Two groups of population were recruited, before and after the inclusion of some phthalates in the authorization list in REACH: the first group of 157 volunteers was studied in 2011 and the second, 171 volunteers, in 2016. Each subject completed a questionnaire about personal lifestyle, working activities and use of chemical products. The main urinary metabolites of five phthalates were analyzed by HPLC/MS/MS: mono(2-ethylhexyl)phthalate (MEHP) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) for di(2-ethylhexyl)phthalate (DEHP) exposure; monoethylphthalate (MEP) for diethylphtahate (DEP); monobenzylphthalate (MBzP) for butylbenzylphtahalate (BBP) and dibenzylphthalate (DBzP), mono-n-butylphthalate (MnBP) for butylbenzylphtahalate (BBP) and di-n-butylphthalate (DnBP). The results show a significant difference for all metabolites between the two periods, with the exception of MEP in women. The comparison of the two sets of results shows a decrease in urinary metabolites excretion from 2011 to 2016, statistically significant for the three phthalates included in Annex XIV of REACH. DEP, not currently included in the list for authorization, maintains a constant presence in the daily life of the population, particularly for women.

Transcriptomics and metabonomics analyses of maternal DEHP exposure on male offspring

The objectives of this study were to evaluate the effect of maternal Di-2-ethylhexyl phthalate (DEHP) exposure on male offspring and to explore the mechanism of changes with the metabolic alterations and differential genes. Pregnant female Sprague-Dawley (SD) rats were intragastrically administered with 600 mg/kg body weight of DEHP or corn oil (CON) throughout pregnancy and lactation. The growth of male offspring was investigated until 14 weeks old, the indices of blood were detected, and mechanism was studied using metabonomics and transcriptomics. Compared with the CON group, body weight, body length, food intake, body fat weight, Lee's index, organ coefficient, blood lipids, and oral glucose tolerance test (OGTT) of male offspring were not significantly changed in maternal DEHP group. However, serum biochemical indexes such as alanine transaminase (ALT), total protein (TP), albumin (ALB), blood urea nitrogen (BUN), and creatinine (CREA) were markedly reduced in maternal DEHP group (p < 0.05). In addition, insulin level was elevated and catalase (CAT) level was decreased notably in maternal DEHP group compared with the CON group (p < 0.05). Furthermore, thyroxine (T₄) level was lower and thyroid stimulating hormone (TSH) level was higher in maternal DEHP group (p < 0.05). Metabonomics revealed seven principal metabolites were identified, including increased L-allothreonine, creatine, uric acid, retinyl ester, L-palmitoylcarnitine, and decreased glycocholic acid and LysoPC (18:3). Transcriptomics displayed 35 differential genes were involved in the mechanism of maternal DEHP exposure. Therefore, this research confirms the effect of a certain dose of maternal DEHP exposure on male offspring and understands exactly the mechanism of these changes with metabonomics and transcriptomics.

Potential influence of the phthalates on normal liver function and cardiometabolic risk in males

Phthalates are ubiquitous environmental contaminants, massively used in industry as plasticizers and additives in cosmetics, which may impair the human endocrine system inducing fertility problems, respiratory diseases, obesity, and neuropsychological disorders. The aim of this study was to examine the influence of the monoethyl phthalate (MEP) and mono-(2-ethylhexyl) phthalate (MEHP) on the liver function and cardiometabolic risk factors in males. In this research, 102 male participants (51 normal weight and 51 overweight/obese) were enrolled and examined for phthalate metabolites exposure in urine samples after 12 h of fasting. MEP was found in 28.43% (29/102) volunteers, while MEHP was detected among 20.59% (21/102) participants. Statistically significant increment in transaminase serum levels was observed in MEP-positive normal weight subgroup. Linear correlation was obtained between MEP concentration in urine samples and triglyceride (TG) serum levels (r ² = 0.33; p < 0.01), visceral adiposity index (VAI) (r ² = 0.41; p < 0.01), lipid accumulation product (LAP) (r ² = 0.32; p < 0.01), and TG to high-density lipoprotein (HDL) ratio (r ² = 0.40, p < 0.01) among the obese. The MEHP-positive normal weight volunteers had statistically significant increment of body mass index (p = 0.03) compared to MEHP-negative participants. Urine MEHP concentrations were negatively correlated with HDL serum levels (r ² = 0.31; p < 0.05) in the normal weight subgroup. The phthalates exposure may be related to statistically significant ALT and AST serum levels increment as well as with increased BMI, while the phthalate levels in the urine may be correlated with increased TG and decreased HDL cholesterol serum levels and associated with indicators of cardiometabolic risk and insulin resistance as LAP and VAI.

Determination of phthalate diesters and monoesters in human milk and infant formula by fat extraction, size-exclusion chromatography clean-up and gas chromatography-mass spectrometry detection

A sensitive and reliable analytical method was developed for the simultaneous determination of five phthalate diesters and corresponding monoesters in human milk samples and infant formulas. The method involved a liquid-liquid extraction with a CH₂Cl₂/CH₃OH/NaCl 30% 2/1/0.5 (v/v/v) mixture, the clean-up of the extract by size-exclusion chromatography (swelling and elution solvent: cyclohexane/ethyl acetate 9/1v/v), the derivatization of monoesters by trimethylsilyl-diazomethane and instrumental analysis by gas chromatography coupled with mass spectrometry. Recovery was in the range of 83-115% and precision was found between 9% and 21%. For phthalate diesters, method detection limits (MDLs) ranged from hundreds of ng/kg to 4.2μg/kg on a fresh weight milk (f.w.) basis, depending on blank contribution evaluated in matrix. Lower MDLs (0.03-0.8μg/kg f.w.) were achieved for corresponding monoesters. The proposed method was applied to the determination of target compounds in nine human milk samples and four infant formulas, confirming their presence in all samples. However, a generally higher contamination was assessed in artificial milk than in breast milk samples.

Stress-Induced Transcriptional Changes and DNA Damage Associated with Bis(2-ethylhexyl) Adipate Exposure in Zebrafish (Danio rerio) Larvae

The present study evaluates potential toxic effects of bis(2-ethylhexyl) adipate (DEHA) plasticizer to larval (72 h post fertilization) zebrafish (Danio rerio) by analyzing changes in expression levels of stress-related genes (p53, rad51 and xrcc5) and assessing possible DNA damage of DEHA in larvae. The lethal concentration for 50% mortality (LC₅₀) in larval zebrafish exposed for 96 h to 0-200 mg L^-1 DEHA was 89.9 ± 8.03 mg L^-1. A concentration-dependent increase in DNA strand breaks was detected in cells from larvae exposed for 96 h to DEHA. There were some significant differences in induction of stress-related genes in larvae exposed to DEHA relative to control.

Transplacental Transfer of Monomethyl Phthalate and Mono(2-ethylhexyl) Phthalate in a Human Placenta Perfusion System

The transplacental passage of monomethylphtalate (mMP) and mono (2-ethylhexyl) phthalate (mEHP) was studied using an ex vivo placental perfusion model with simultaneous perfusion of fetal and maternal circulation in a single cotyledon. Umbilical cord blood and placental tissue collected both before and after perfusion were also analyzed. Placentas were obtained immediately after elective cesarean section and dually perfused in a recirculation system. mMP or mEHP was added to maternal perfusion medium to obtain concentrations at 10 and 25 μg/L, respectively. The placental transfer was followed analyzing samples from fetal and maternal perfusion media by liquid chromatography–mass spectrometry–mass spectrometry (LC-MS-MS). Four perfusions with mMP indicated a slow transplacental transfer, with a fetomaternal ratio (FM ratio) of 0.30 ± 0.03 after 150 min of perfusion. Four perfusions with mEHP indicated a very slow or nonexisting placental transfer. mEHP was only detected in fetal perfusion media from two perfusions, giving rise to FM ratios of 0.088 and 0.20 after 150 min of perfusion. Detectable levels of mMP, mEHP, monoethylphthalate (mEP), and monobutylphthalate were found in tissue. Higher tissue levels of mMP after perfusions with mMP compared to perfusions with mEHP suggest an accumulation of mMP during perfusion. No tendency for accumulation of mEHP was observed during perfusions with mEHP compared to perfusions with mMP. Detectable levels of mEHP and mEP were found in umbilical cord plasma samples. mMP and possibly other short-chained phthalate monoesters in maternal blood can cross the placenta by slow transfer, whereas the results indicate no placental transfer of mEHP. Further studies are recommended.

Exposures to Endocrine Disrupting Chemicals in Consumer Products-A Guide for Pediatricians

Endocrine disrupting chemicals, a group of exogenous chemicals that can interfere with hormone action in the body, have been implicated in disrupting endocrine function, which negatively affects human health and development. Endocrine disrupting chemicals are ubiquitously detected in consumer products, foods, beverages, personal care products, and household cleaning products. Due to concerns about their negative effects on human health, several professional health provider societies have recommended the reduction of common endocrine disrupting chemical exposures. The purpose of this review is to provide a brief overview of common endocrine disrupting chemicals (bisphenol A, phthalates, triclosan, polybrominated ethers, and parabens) and potential effects on child development and health. In addition, we aim to provide guidance and resources for pediatricians and other health care providers with counseling strategies to help patients to minimize exposures to common endocrine disrupting chemicals.

Human exposure to endocrine disrupting compounds: Their role in reproductive systems, metabolic syndrome and breast cancer. A review

Endocrine disrupting chemicals (EDCs) are released into the environment from different sources. They are mainly used in packaging industries, pesticides and food constituents. Clinical evidence, experimental models, and epidemiological studies suggest that EDCs have major risks for humans by targeting different organs and systems in the body (e.g. reproductive system, breast tissue, adipose tissue, pancreas, etc.). Due to the ubiquity of human exposure to these compounds the aim of this review is to describe the most recent data on the effects induced by phthalates, bisphenol A and parabens in a critical window of exposure: in utero, during pregnancy, infants, and children. The interactions and mechanisms of toxicity of EDCs in relation to human general health problems, especially those broadening the term of endocrine disruption to 'metabolic disruption', should be deeply investigated. These include endocrine disturbances, with particular reference to reproductive problems and breast, testicular and ovarian cancers, and metabolic diseases such as obesity or diabetes.

Breastfeeding Duration and Anogenital Distance in 2-Year-Old Infants

BACKGROUND

The anogenital distance (AGD) is an anthropometric marker determined by exposures to androgens in utero and throughout the first few months of life. Early exposures to endocrine-disrupting chemicals such as phthalates have been significantly associated with shortened AGD in boys. Limited studies have explored phthalate concentrations in breast milk and infant formula.

OBJECTIVE

To explore the associations between breastfeeding duration and AGD measures in infants.

MATERIALS AND METHODS

MALAMA (Medio Ambiente y Lactancia Materna) is a follow-up study of 430 mother-child pairs, from birth to 2 years, from two population-based cohorts in Murcia, Spain. Data were collected through medical visits and telephone surveys from birth to 2 years of age. World Health Organization breastfeeding definitions were used. AGD measurements were assessed in a subsample of 71 boys and 49 girls at the 2-year visit. Descriptive analyses, Pearson correlations, and linear regressions were calculated between AGD and breastfeeding duration.

RESULTS

Duration of all types of breastfeeding, especially full breastfeeding (FB), is correlated with AGD measures in boys (p < 0.05). AGDAS (anoscrotal distance) and AGDAP (anopenile distance) were positively associated with FB (β = 0.004, 95%CI: 0.001-0.007 and β = 0.003, 95%CI: 0.000-0.007, respectively).

CONCLUSIONS

A positive correlation between AGD in male infants and the duration of breastfeeding is reported. Inversely, early introduction of infant formula could lead to the reduction of AGD in boys.

Food Emulsifier Glycerin Monostearate Increases Internal Exposure Levels of Six Priority Controlled Phthalate Esters and Exacerbates Their Male Reproductive Toxicities in Rats

Human beings are inevitably exposed to ubiquitous phthalate esters (PAEs). Processed, packaged foods are popular nowadays, in which emulsifiers are frequently added as food additives. It is unclear how emulsifiers affect the bioavailability of ingested PAEs contaminants and their toxicities. The purposes of our study were to explore whether food emulsifier Glycerin Monostearate (GMS) could increase the internal exposure levels of six priority controlled PAEs and affect their reproductive toxicities when male rats are exposed to PAEs mixture (MIXPs). The male rats were exposed to MIXPs by gavage for thirty days in combination with or without given GMS. Phthalate monoesters (MPAEs), primary metabolites of PAEs, in rat urine were used as biomarkers to predict the internal exposure levels of the six PAEs, and their concentrations were determined using UPLC-MS. The reproductive toxicity was evaluated using serum testosterone levels test and histopathology of testes. Results showed that compared to PAEs exposure alone, the internal exposure levels of PAEs increased by 30%-49% in the presence of GMS. PAEs exposure led to the reduction of testosterone level by 23.4%-42.1% in the presence and absence of GMS, respectively, compared to the baseline. Testosterone levels in MIXPs+GMS and DEHP+GMS group were decreased by 9.1% and 13.6%, respectively, compared with MIXPs and DEHP group. Histopathology showed that injuries of testis (deciduous spermatids) were observed, and GMS exacerbated the injuries. The results indicated food emulsifiers chronically taken up might increase safety risks of food PAEs contaminants.

Phthalates in neonatal health: friend or foe?

Exposure to environmental chemicals has adverse effects on the health and survival of humans. Emerging evidence supports the idea that exposure to endocrine-disrupting compounds (EDCs) can perturb an individual’s physiological set point and as a result increase his/her propensity toward several diseases. The purpose of this review is to provide an update on di-(2-ethylhexyl) phthalate, the primary plasticizer found in plastic medical devices used in neonatal intensive care units, its effects on the fetus and newborn, epidemiological studies, pharmacokinetics, toxicity and epigenetic implications. We searched the PubMed databases to identify relevant studies. Phthalates are known EDCs that primarily are used to improve the flexibility of polyvinyl chloride plastic products and are called plasticizers in lay terms. Neonates and infants are particularly vulnerable to the effects of phthalates, beginning with maternal exposure and placental transfer during gestation and during infancy following birth. In line with the developmental origins of adult disease, a focus on the effects of environmental chemicals in utero or early childhood on the genesis of adult diseases through epigenome modulation is timely and important. The epigenetic effects of phthalates have not been fully elucidated, but accumulating evidence suggests that they may be associated with adverse health effects, some of which may be heritable. Phthalate exposure during pregnancy and the perinatal period is particularly worrisome in health-care settings. Although the clinical significance of phthalate exposure has been difficult to assess with epidemiologic studies, the evidence that physiological changes occur due to exposure to phthalates is growing and points toward the need for more investigation at a molecular, specifically epigenetic level.

Maternal and early life exposure to phthalates: The Plastics and Personal-care Products use in Pregnancy (P4) study

Phthalates are a group of chemicals found in a number of consumer products; some of these phthalates have been shown to possess estrogenic activity and display anti-androgenic effects. While a number of biomonitoring studies of phthalates in pregnant women and infants have been published, there is a paucity of data based on both multiple sampling periods and in different matrices. Phthalate metabolites were measured in 80 pregnant women and their infants in Ottawa Canada (2009-2010) in urine, meconium and breast milk collected at various time periods pre- and post-parturition. At least 50% of the women had at least one urine sample greater than the limit of detection (LOD) for the various phthalate metabolites, with the exception of mono-n-octyl phthalate (MnOP), mono-isononyl phthalate (MiNP) and mono(carboxy-isooctyl) phthalate (MCiOP). Four major clusters of maternal urinary metabolites were identified. Among infants (n=61), the following metabolites were rarely (< 10%) detected: mono-cyclohexyl phthalate (MCHP), mono-isononyl phthalate (MiNP), mono-methyl phthalate (MMP), and mono-n-octyl phthalate (MnOP). While mono-benzyl phthalate (MBzP), mono-3-carboxypropyl phthalate (MCPP), MEHHP, and MEOHP were frequently detected in maternal urines at any time point, these metabolites were rarely detected in breast milk. Maternal urinary concentrations of MEP and the DEHP metabolites were higher in samples collected during pregnancy than postnatally. No statistically significant differences were observed in infant's urinary phthalate concentrations between breast-fed and bottle-fed infants. Significant correlations were observed between maternal urinary MEHHP (r=0.35), MEOHP (r=0.35) and MEP (r=0.37) collected at <20weeks gestation with levels in meconium and between MBzP (r=0.78) and MEP (r=0.56) in maternal and infant urine collected 2-3months after birth. These results suggest at least some maternal-fetal-infant transfer of phthalates and that meconium may be a useful matrix for measuring in utero exposure to phthalates.

Pollution levels and characteristics of phthalate esters in indoor air in hospitals

The concentrations of phthalate esters (PAEs) in Chinese hospitals were investigated by simultaneously determining concentrations of gas- and particle-phase PAEs. PAEs were detected in two third-class first-grade hospitals, two second-class first-grade hospitals, and a community health service center. Hospital drugstores had the highest concentration (24.19μg/m(3)), which was 1.54 times that of newly decorated houses. The second highest concentration was found in the transfusion rooms, averaging 21.89μg/m(3); this was followed by the concentrations of PAEs in the nurse's workstations, the wards, and the doctor's offices, with mean concentrations of 20.66, 20.0, and 16.92μg/m(3), respectively. The lowest concentrations were found in the hallways (16.30μg/m(3)). Of the six different kinds of PAEs found, major pollutants included diethyl phthalates, dibutyl phthalates, butylbenzyl phthalates and di(2-ethylhexyl) phthalates, comprising more than 80% of all PAEs present. Meanwhile, a comparison between different wards showed that PAE concentrations in the maternity wards were 1.63 times higher than in the main wards. Based on known health hazards, our results suggest that the PAEs seriously influence the health of the pregnant women and babies; therefore, it is of great importance to take the phthalate concentrations in hospitals into consideration. In addition, hospital indoor air was more seriously contaminated than the air of newly decorated houses.