Phthalate exposure and children's health

Blood Bag Plasticizers Influence Red Blood Cell Vesiculation Rate without Altering the Lipid Composition of the Vesicles

BACKGROUND

Polyvinyl chloride (PVC) plasticized with di(2-ethylhexyl) phthalate (DEHP) is commonly used for blood collection and storage. DEHP has protective effects on RBC membranes, but is also a toxin.

METHODS

A paired study was conducted to investigate the influence of DEHP and two alternative plasticizers, 1,2-cyclohexane-dicarboxylic acid diisononyl ester (DINCH) and n-butyryl-tri-n-hexyl citrate (BTHC), on the preservation of RBCs stored for 42 days in PVC pediatric bags. The RBC membrane was evaluated for supernatant hemoglobin (Hb), release of extracellular microvesicles (EVs), osmotic fragility, deformability, and lipid composition.

RESULTS

In BTHC-plasticized bags, the supernatant Hb increase during storage was 2 times greater than in DINCH- and DEHP-plasticized bags. By day 21, EV concentrations had doubled from day-5 levels in DINCH- and DEHP-, and trebled in BTHC-plasticized bags. RBC mean cell volumes were greater in BTHC- than in DINCH- or DEHP-plasticized bags (p < 0.001). Osmotic fragility differed significantly among plasticizers (p < 0.01). After day 21, RBC deformability decreased in all, but to a greater extent in the bags with BTHC. Phospholipid composition of RBCs and EVs was not different among plasticizers.

CONCLUSION

Membrane stabilization capacity differed among the plasticizers. RBC in BTHC bags stored more poorly, while DEHP and DINCH bags offered better protection against vesiculation, osmotic stress, and Hb loss.

Obstetrical outcomes and biomarkers to assess exposure to phthalates: A review

Studies of the effects on pregnancy outcomes of in utero exposure to phthalates, contaminants that are widely present in the environment, have yielded conflicting results. In addition, the mode of assessment of exposure varies between studies. The aim of this review was therefore to establish a current state of knowledge of the phthalates and metabolites involved in unfavorable pregnancy outcomes. Extant data were analyzed to determine which biomarker is the best suited to assess the relation between in utero exposure to phthalates and pregnancy outcomes. This review of the literature was conducted using the database of PubMed. A search was made of studies investigating exposure to phthalates and the following birth outcomes: preterm birth (gestational age <37 weeks), change in gestational age, change in body size at birth (birth weight, length, head circumference), anti-androgenic function, decreased anogenital distance, cryptorchidism, hypospadias and congenital malformation. The methodological approach adopted in each study was examined, in particular the methods used for exposure assessment (biomarkers and/or questionnaire). Thirty-five studies were included. Premature birth and decreased anogenital distance were the most commonly reported outcomes resulting from a moderate level of exposure to phthalates. The principal metabolites detected and involved were primary metabolites of di-2(ethylhexyl)-phthalate (DEHP) and di-n-butyl-phthalate (DnBP). No clear conclusion could be drawn with regard to gestational age at birth, body size at birth and congenital malformations. In epidemiological studies, maternal urine is the most suitable matrix to assess the association between in utero exposure to phthalates and pregnancy outcomes: in contrast to other matrices (cord blood, amniotic fluid, meconium and milk), sampling is easy, non-invasive and, can be repeated to assess exposure throughout pregnancy. Oxidative metabolites are the most relevant biomarkers since they are not prone to external contamination. Further epidemiological studies are required during pregnancy to i) determine the role of phthalates other than DEHP [currently replaced by various substitution products, in particular diisononyl-phthalate (DiNP)]; ii) establish the effect of phthalates on other outcomes (body size adjusted for gestational age, and congenital malformations); iii) determine the pathophysiological pathways; and iv) identify the most suitable time for biomarker determination of in utero exposure to phthalates.

Urinary phthalate metabolite concentrations in relation to history of infertility and use of assisted reproductive technology

OBJECTIVE

To examine urinary phthalate metabolite concentrations in pregnant women with planned pregnancies in relation to history of infertility and use of assisted reproductive technology (ART).

DESIGN

Phthalate metabolite concentrations were measured in first-trimester urine samples collected from women participating in a prospective pregnancy cohort study.

SETTING

Prenatal clinics.

PATIENT(S)

A total of 750 women, of whom 86 had a history of infertility. Forty-one women used ART to conceive.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcomes were concentrations of four metabolites of diethylhexyl phthalate (DEHP) and their molar sum (∑DEHP). Multivariable analyses compared phthalate metabolite levels in [1] women reporting a history of infertility vs. those who did not (comparison group); and [2] those who used ART to conceive the index pregnancy vs. women with a history of infertility who did not use ART.

RESULT(S)

Among women with a history of infertility, ∑DEHP was significantly lower in women who conceived after ART compared with those who did not (geometric mean ratio: 0.83; 95% confidence interval 0.71-0.98). Similar significant associations were observed for all of the individual DEHP metabolites. There were no differences in DEHP metabolite concentrations between women with a history of infertility and the comparison group.

CONCLUSION(S)

Women who used ART to conceive had lower first-trimester phthalate metabolite concentrations than women with a history of infertility who did not use ART. Further research is needed to explore whether those pursuing fertility treatments take precautions to avoid exposure to environmental toxins, to improve treatment outcomes.

The adverse cardiac effects of Di(2-ethylhexyl)phthalate and Bisphenol A

The ubiquitous nature of plastics has raised concerns pertaining to continuous exposure to plastic polymers and human health risks. Of particular concern is the use of endocrine-disrupting chemicals in plastic production, including di(2-ethylhexyl)phthalate (DEHP) and bisphenol A (BPA). Widespread and continuous exposure to DEHP and BPA occurs through dietary intake, inhalation, dermal and intravenous exposure via consumer products and medical devices. This article reviews the literature examining the relationship between DEHP and BPA exposure and cardiac toxicity. In vitro and in vivo experimental reports are outlined, as well as epidemiological studies which examine the association between these chemicals and cardiovascular outcomes. Gaps in our current knowledge are also discussed, along with future investigative endeavors that may help resolve whether DEHP and/or BPA exposure has a negative impact on cardiovascular physiology.

Exposure to select phthalates and phenols through use of personal care products among Californian adults and their children

INTRODUCTION

Certain phenols and phthalates are used in many consumer products including personal care products (PCPs).

AIMS

We aimed to study the associations between the use of PCPs and urinary concentrations of biomarkers of select phenols and phthalates among Californian adults and their children. As an additional aim we compared phenols and phthalate metabolites concentrations measured in adults and children urine samples collected the same day.

METHODS

Our study relied on a subsample of 90 adult-child pairs participating in the Study of Use of Products and Exposure Related Behavior (SUPERB). Each adult and child provided one to two urine samples in which we measured concentrations of selected phenols and phthalate metabolites. We computed Spearman correlation coefficients to compare concentrations measured in adults and children urine samples collected the same day. We used adjusted linear and Tobit regression models to study the associations between the use of PCPs in the past 24h and biomarker concentrations.

RESULTS

Benzophenone-3 and parabens concentrations were higher in adults compared to their children. Conversely children had higher mono-n-butyl phthalate and mono-isobutyl phthalate concentrations. No significant difference was observed for the other compounds. The total number of different PCPs used was positively associated with urinary concentrations of methyl, propyl and butyl parabens and the main metabolite of diethyl phthalate in adults. Among children, the use of a few specific products including liquid soap, hair care products and sunscreen was positively associated with urinary concentrations of some phenols or phthalate metabolites.

DISCUSSION

These results strengthen the body of evidence suggesting that use of PCPs is an important source of exposure to parabens and diethyl phthalate in adults and provide data on exposure to selected phenols and phthalates through use of PCPs in children.

Fetal and Childhood Exposure to Phthalate Diesters and Cognitive Function in Children Up to 12 Years of Age: Taiwanese Maternal and Infant Cohort Study

Few studies have examined the association between environmental phthalate exposure and children’s neurocognitive development. This longitudinal study examined cognitive function in relation to pre-and postnatal phthalate exposure in children 2–12 years old. We recruited 430 pregnant women in their third trimester in Taichung, Taiwan from 2001–2002. A total of 110, 79, 76, and 73 children were followed up at ages 2, 5, 8, and 11, respectively. We evaluated the children’s cognitive function at four different time points using the Bayley and Wechsler tests for assessing neurocognitive functions and intelligence (IQ). Urine samples were collected from mothers during pregnancy and from children at each follow-up visit. They were analyzed for seven metabolite concentrations of widely used phthalate esters. These esters included monomethyl phthalate, monoethyl phthalate, mono-butyl phthalate, mono-benzyl phthalate, and three metabolites of di(2-ethylhexyl) phthalate, namely, mono-2-ethylhexyl phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate, and mono(2-ethyl-5-oxohexyl) phthalate. We constructed a linear mixed model to examine the relationships between the phthalate metabolite concentrations and the Bayley and IQ scores. We found significant inverse associations between the children’s levels of urinary mono(2-ethyl-5-oxohexyl) phthalate and the sum of the three metabolites of di(2-ethylhexyl) phthalate and their IQ scores (β = -1.818; 95% CI: -3.061, -0.574, p = 0.004 for mono(2-ethyl-5-oxohexyl) phthalate; β = -1.575; 95% CI: -3.037, -0.113, p = 0.035 for the sum of the three metabolites) after controlling for maternal phthalate levels and potential confounders. We did not observe significant associations between maternal phthalate exposure and the children’s IQ scores. Children’s but not prenatal phthalate exposure was associated with decreased cognitive development in the young children. Large-scale prospective cohort studies are needed to confirm these findings in the future.

DESI MS based screening method for phthalates in consumer goods

Phthalates are used as plasticizes in many everyday items, but some of them are known as hormone disruptors, being especially harmful during childhood. The European Union therefore restricted their application in children's toys and certain food packaging to 0.1%w. Due to the ever increasing number of plastic-containing consumer goods, rapid screening methods are needed to ensure and improve consumer safety in the future. In this study we evaluated the performance of desorption electrospray ionization (DESI) mass spectrometry (MS) for rapid quantitative screening of phthalates in toys. DESI allowed for direct surface sampling of the toys under atmospheric conditions with minimal sample preparation, while the high performance mass spectrometer used provided a high sensitivity and reliable identification via accurate mass measurements, high mass resolving power and MS/MS capabilities. External calibration curves for six banned phthalates (DBP, BBP, DEHP, DNOP, DINP and DIDP) were obtained from matrix-matched reference materials. Coefficients of determination were greater than 0.985, LOQs ranged from 0.02%w (DIDP) to 2.26%w (DINP) and the relative standard deviation of the calibration curve slope was less than 7.8% for intraday and 11.4% for interday comparison. The phthalate contents of eleven authentic samples were determined in a proof-of-concept approach using DESI MS and results were compared to those from confirmatory methods. The phthalate content was correctly assigned with relative deviations ranging from -20% to +10% for the majority of samples. Given further optimization and automation, DESI MS is likely to become a useful tool for rapid and accurate phthalate screening in the future.

Phthalate exposure through different pathways and allergic sensitization in preschool children with asthma, allergic rhinoconjunctivitis and atopic dermatitis

Studies in rodents indicate that phthalates can function as adjuvants, increasing the potency of allergens. Meanwhile, epidemiological studies have produced inconsistent findings regarding relationships between phthalate exposures and allergic disease in humans. The present study examined phthalate exposure and allergic sensitization in a large group of 3-5 year old children: 300 random controls and 200 cases with asthma, rhinoconjunctivitis or atopic dermatitis as reported in questionnaires. The children were clinically examined to confirm their health status. Blood samples were analyzed for IgE sensitization to 20 allergens. Adjusted logistic regressions were used to look for associations between phthalate exposure indicators (mass fractions in dust from children's homes and daycares, metabolites in urine, and estimated daily indoor intakes from dust ingestion, inhalation and dermal absorption) and sensitization and allergic disease. No direct associations were found between phthalate exposures and asthma, rhinoconjunctivitis or atopic dermatitis. However, among children with these diseases, there were significant associations between non-dietary exposures to DnBP, BBzP and DEHP in the indoor environment (mass fractions in dust or daily indoor intakes from dust ingestion, inhalation and dermal absorption) and allergic sensitization. Some exposure pathways were more strongly associated with sensitization than others, although the results are not conclusive and require confirmation. A number of the associations depended on accounting for a child's exposure in more than one environment (i.e., daycare facility as well as home). Significant associations were not observed between phthalate metabolites in urine, which reflected exposure from diet as well as indoor pathways, and allergic sensitization.

Urinary phthalate metabolite concentrations and blood glucose levels during pregnancy

PURPOSE

To examine associations between phthalate metabolite urinary concentrations during early pregnancy and blood glucose levels obtained at the time of screening for gestational diabetes mellitus (GDM).

METHODS

Upon initiation of prenatal care, women with a mean gestational age of 12.8 weeks were recruited for a study of environmental chemical exposures (n = 110) and provided a spot urinary specimen. Blood glucose concentrations (mg/dl) were obtained from the electronic medical record for those patients who did not experience a pregnancy loss and did not transfer care to another facility prior to glucose screening (n = 72). Urinary concentrations of nine phthalate metabolites and creatinine were measured at the US Centers for Disease Control and Prevention. Associations between tertiles of phthalate metabolites concentrations and blood glucose levels were estimated using linear regression.

RESULTS

Compared to pregnant women in the lowest concentration tertile, women with the highest urinary concentrations (≥ 3 rd tertile) of mono-iso-butyl phthalate (tertile: ≥ 15.3 μg/l, β = -18.3, 95% CI: -35.4, -1.2) and monobenzyl phthalate (tertile: ≥ 30.3 μg/l, β = -17.3, 95% CI: -34.1, -0.4) had lower blood glucose levels at the time of GDM screening after adjustment for urinary creatinine and demographic covariates.

CONCLUSION

Because maternal glucose levels increase during pregnancy to provide adequate nutrition for fetal growth and development, these findings may have implications for fetal health. However, given the limitations of our study, findings should be interpreted cautiously.

Assessing exposure of young children to common endocrine-disrupting chemicals in the home environment: a review and commentary of the questionnaire-based approach

BACKGROUND

Although infants and young children are particularly vulnerable to endocrine disrupting chemical (EDC) exposure, there is an absence of comprehensive exposure data for this age group. As young children spend the majority of their time indoors, improved methods of exposure assessment are needed to characterise the health risks from exposures in the home environment. Biologic assessment, which has been considered the gold standard for exposure assessment in recent years, is difficult to conduct in young children. Questionnaires are an alternative and indirect method of predicting exposure, which may overcome some of the limitations of direct exposure assessment.

RESEARCH PROBLEM

The feasibility of using a questionnaire-based approach to predict exposure of young children to EDCs in the home has yet to be comprehensively reviewed. Moreover, there is no one questionnaire that has been validated for predicting the exposure of infants to common EDCs in the home.

AIMS AND OBJECTIVES

The aim of this review is to discuss the use and validation of the questionnaire-based approach to predict exposure of children to chemicals from three common classes of EDCs in the home, namely, plasticisers, flame retardants, and insecticides. We discuss the strengths and weaknesses of the questionnaire-based approach as well as the important pathways of exposure in the home environment, by which to guide the design and validation of future exposure questionnaires.

RESULTS

The findings from our review indicate that the questionnaire-based approach is a valuable tool in the prediction of exposure to persistent organic pollutants, as well as to toxicants that have consistent patterns of exposure. With improvements to the design and validation process, the questionnaire-based approach may also prove to be a reliable instrument in predicting exposure to EDCs with short-half lives, including bisphenol A, phthalates, and pyrethroid and organophosphate insecticides.

Persistent Associations between Maternal Prenatal Exposure to Phthalates on Child IQ at Age 7 Years

Background

Prior research reports inverse associations between maternal prenatal urinary phthalate metabolite concentrations and mental and motor development in preschoolers. No study evaluated whether these associations persist into school age.

Methods

In a follow up of 328 inner-city mothers and their children, we measured prenatal urinary metabolites of di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP), di-isobutyl phthalate (DiBP), di-2-ethylhexyl phthalate and diethyl phthalate in late pregnancy. The Wechsler Intelligence Scale for Children, 4th edition was administered at child age 7 years and evaluates four areas of cognitive function associated with overall intelligence quotient (IQ).

Results

Child full-scale IQ was inversely associated with prenatal urinary metabolite concentrations of DnBP and DiBP: b = −2.69 (95% confidence interval [CI] = −4.33, −1.05) and b = −2.69 (95% CI = −4.22, −1.16) per log unit increase. Among children of mothers with the highest versus lowest quartile DnBP and DiBP metabolite concentrations, IQ was 6.7 (95% CI = 1.9, 11.4) and 7.6 (95% CI = 3.2, 12.1) points lower, respectively. Associations were unchanged after control for cognition at age 3 years. Significant inverse associations were also seen between maternal prenatal metabolite concentrations of DnBP and DiBP and child processing speed, perceptual reasoning and working memory; DiBP and child verbal comprehension; and BBzP and child perceptual reasoning.

Conclusion

Maternal prenatal urinary metabolite concentrations measured in late pregnancy of DnBP and DiBP are associated with deficits in children’s intellectual development at age 7 years. Because phthalate exposures are ubiquitous and concentrations seen here within the range previously observed among general populations, results are of public health significance.

Variability and predictors of urinary phthalate metabolites in Spanish pregnant women

Developmental exposure to phthalates may be associated with adverse health outcomes but information on the variability and predictors of urinary phthalate metabolite concentrations during pregnancy is limited. We evaluated in Spanish pregnant women (n=391) the reproducibility of urinary phthalate metabolite concentrations and predictors of exposure. We measured mono-(4-methyl-7-hydroxyoctyl) phthalate (7-OHMMeOP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-(2-carboxyhexyl) phthalate (MCMHP), mono-benzyl phthalate (MBzP), mono-ethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP) in two spot urine samples collected in the first and third pregnancy trimesters. Questionnaires on predictors and food-frequency questionnaires were administered in the first and/or third pregnancy trimesters. Using creatinine-adjusted phthalate metabolite concentrations (log10-trasformed) we calculated intraclass correlation coefficients (ICCs). Linear mixed and regression models assessed the associations between predictors and phthalate metabolites. The ICCs ranged from 0.24 to 0.07 and were higher for MBzP, MEP, MiBP, and lower for MEOHP and MEHHP. Overweight, lower education and social class, and less frequent consumption of organic food were associated with higher levels of some phthalate metabolites. The use of household cleaning products (bleach, ammonia, glass cleaners, oven cleaning sprays and degreasing products) at least once per week during pregnancy was associated with 10-44% higher urinary phthalate metabolites. Bottled-water consumption, consumption of food groups usually stored in plastic containers or cans, use of plastic containers for heating food and cosmetic use were not associated with increased concentrations of phthalate metabolites. This large study with repeated phthalate measurements suggests that, in this Spanish setting, sociodemographic and lifestyle factors and household cleaning product use are better predictors of phthalate exposure levels in pregnant women than average water and food consumption and use of plastic containers and cosmetics.

Prenatal exposure to bisphenol A and phthalates and childhood respiratory tract infections and allergy

BACKGROUND

There is growing concern that prenatal exposure to bisphenol A (BPA) and phthalates, which are widely used in consumer products, might affect susceptibility to infections and the development of allergy and asthma in children, but there are currently very few prospective studies.

OBJECTIVE

We sought to evaluate whether prenatal exposure to BPA and phthalates increases the risk of respiratory and allergic outcomes in children at various ages from birth to 7 years.

METHODS

We measured BPA and metabolites of high-molecular-weight phthalates, 4 di-(2-ethylhexyl) phthalate (DEHP) metabolites (Σ4DEHP) and mono-benzyl phthalate (MBzP), and 3 low-molecular-weight phthalate (LMWP) metabolites (Σ3LMWP) in urine samples collected during the first and third trimesters in pregnant women participating in the Infancia y Medio Ambiente-Sabadell birth cohort study. The occurrence of chest infections, bronchitis, wheeze, and eczema in children was assessed at ages 6 and 14 months and 4 and 7 years through questionnaires given to the mothers. Atopy (specific IgE measurement) and asthma (questionnaire) were assessed at ages 4 and 7 years, respectively.

RESULTS

The relative risks (RRs) of wheeze (RR, 1.20; 95% CI, 1.03-1.40; P = .02), chest infections (RR, 1.15; 95% CI, 1.00-1.32; P = .05), and bronchitis (RR, 1.18; 95% CI, 1.01-1.37; P = .04) at any age increased for each doubling in concentration of maternal urinary BPA. Σ4DEHP metabolites were associated with the same outcomes (wheeze: RR, 1.25; 95% CI, 1.04-1.50, P = .02; chest infections: RR, 1.15; 95% CI, 0.97-1.35; P = .11; bronchitis: RR, 1.20; 95% CI, 1.01-1.43; P = .04). MBzP was associated with higher risk of wheeze (RR, 1.15; 95% CI, 1.00-1.33; P = .05). The risk of asthma at age 7 years was also increased with increasing prenatal BPA, Σ4DEHP, and MBzP exposure. There were no other exposure-outcome associations.

CONCLUSIONS

Prenatal exposure to BPA and high-molecular-weight phthalates might increase the risk of asthma symptoms and respiratory tract infections throughout childhood.

Early-life origins of chronic respiratory diseases: understanding and promoting healthy ageing

Chronic obstructive respiratory disorders such as asthma and chronic obstructive pulmonary disease often originate early in life. In addition to a genetic predisposition, prenatal and early-life environmental exposures have a persistent impact on respiratory health. Acting during a critical phase of lung development, these factors may change lung structure and metabolism, and may induce maladaptive responses to harmful agents, which will affect the whole lifespan. Some environmental factors, such as exposure to cigarette smoke, type of childbirth and diet, may be modifiable, but it is more difficult to influence other factors, such as preterm birth and early exposure to viruses or allergens. Here, we bring together recent literature to analyse the critical aspects involved in the early stages of lung development, going back to prenatal and perinatal events, and we discuss the mechanisms by which noxious factors encountered early on may have a lifelong impact on respiratory health. We briefly comment on the need for early disease biomarkers and on the possible role of "-omic" technologies in identifying risk profiles predictive of chronic respiratory conditions. Such profiles could guide the ideation of effective preventive strategies and/or targeted early lifestyle or therapeutic interventions.

Views of pregnant women and clinicians regarding discussion of exposure to phthalate plasticizers

OBJECTIVE

This study explores the views of pregnant women and clinicians regarding discussion of exposure to phthalate plasticizers during pregnancy, subsequent to the 2011 Health Canada ban of certain phthalates at a concentration greater than 1000 mg/kg in baby toys. This occurred with no regulation of products to which pregnant women are exposed, such as food packaging and cosmetics.

METHODS

Pregnant women, physicians and midwives were recruited through posters and pamphlets in prenatal clinics in Southwestern Ontario for a semi-structured interview. All interviews were audiotaped, transcribed, and subjected to rigorous qualitative analysis through a grounded theory approach, supported by NVIVO™ software. Themes emerged from line by line, open, and axial coding in an iterative manner.

RESULTS

Theoretical sufficiency was reached after 23 pregnant women and 11 clinicians had been interviewed. The themes (and subthemes from which they arose) were: Theme I-Information Provision (IA-Sources of Information, IB-Standardization, IC-Constraints, ID-Role of Government); Theme II-Risk (IIA-Significant Risk, IIB-Perceived Relevance, IIC-Reconciliation); and Theme III- Factors Influencing Level of Concern (IIIA-Current Knowledge, IIIB-Demographic Factors).

CONCLUSION

To respond to the increasing media and research attention regarding risk of phthalates to women, and pregnant women in particular, national professional organizations should provide patient information. This could include pamphlets on what a pregnant woman should know about phthalates and how they can be avoided, as well as information to clinicians to facilitate this discussion.

Luminescent threat: toxicity of light stick attractors used in pelagic fishery

Light sticks (LS) are sources of chemiluminescence commonly used in pelagic fishery, where hundreds are discarded and reach the shores. Residents from fishing villages report an improper use of LS contents on the skin. Given the scarce information regarding LS toxicity, the effects of LS solutions in cell cultures were evaluated herein. Loss of viability, cell cycle changes and DNA fragmentation were observed in HepG2 cell line and skin fibroblasts. A non-cytotoxic LS concentration increased the occurrence of the mutagenic lesion 1,N(6)-εdAdo in HepG2 DNA by three-fold. Additionally, in vitro incubations of spent LS contents with DNA generated dGuo-LS adducts, whose structure elucidation revealed the presence of a reactive chlorinated product. In conclusion, the LS contents were found to be highly cyto- and genotoxic. Our data indicate an urgent need for LS waste management guidelines and for adequate information regarding toxic outcomes that may arise from human exposure.

Prenatal and peripubertal phthalates and bisphenol A in relation to sex hormones and puberty in boys

Phthalates and BPA are known endocrine disruptors and exposure in pregnant mothers and children is ubiquitous. We explored the relationship of prenatal and childhood exposures with pubertal onset and sex hormones in boys (ages 8-14). Phthalate metabolites and BPA were measured in maternal 3rd trimester or childhood urine. Sex hormones DHEAS, estradiol, inhibin B, SHBG, and total testosterone were measured in serum. Adrenarche and puberty were assessed by pediatrician. Prenatal exposure to some phthalates was associated with decreased DHEAS and inhibin B levels, and with increased SHBG. Prenatal exposure to most phthalates and BPA was associated with greatly reduced odds of adrenarche (odds ratios [OR]=0.12-0.65) and slightly reduced odds of puberty (OR=0.50-0.98). Childhood exposure was not associated with adrenarche or puberty, but some phthalates and BPA were associated with increased SHBG levels and decreased total and free testosterone levels.

Phthalates and diet: a review of the food monitoring and epidemiology data

Phthalates are associated with a variety of health outcomes, but sources that may be targeted for exposure reduction messaging remain elusive. Diet is considered a significant exposure pathway for these compounds. Therefore, we sought to identify primary foods associated with increased exposure through a review of the food monitoring survey and epidemiological data. A search in PubMed and Google Scholar for keywords "phthalates" and "diet" "food" "food stuffs" "dietary intake" "food intake" and "food concentration" resulted in 17 studies measuring phthalate concentrations in United States (US) and international foods, three epidemiological association studies, and three interventions. We report on food groups with high (≥300 μg/kg) and low (<50 μg/kg) concentrations and compare these to foods associated with phthalate body burden. Based on these data, we estimated daily intakes of di-2-ethylhexyl phthalate (DEHP) of US women of reproductive age, adolescents and infants for typical consumption patterns as well as healthy and poor diets. We consistently observed high DEHP concentrations in poultry, cooking oils and cream-based dairy products (≥300 μg/kg) across food monitoring studies. Diethyl phthalate (DEP) levels were found at low concentrations across all food groups. In line with these data, epidemiological studies showed positive associations between consumption of meats, discretionary fat and dairy products and DEHP. In contrast to food monitoring data, DEP was found to be associated with intake of vegetables in two studies. DEHP exposure estimates based on typical diets were 5.7, 8.1, and 42.1 μg/kg-day for women of reproductive age, adolescents and infants, respectively, with dairy as the largest contributor to exposure. Diets high in meat and dairy consumption resulted in two-fold increases in exposure. Estimates for infants based on a typical diet exceeded the Environmental Protection Agency's reference dose of 20 μg/kg-day while diets high in dairy and meat consumed by adolescents also exceeded this threshold. The review of the literature demonstrated that DEHP in some meats, fats and dairy products is consistently found in high concentrations and can contribute to exposure. Guidance on future research in this area is provided that may help to identify methods to reduce dietary phthalate exposures.

Peroxisome proliferator-activated receptor α mediates di-(2-ethylhexyl) phthalate transgenerational repression of ovarian Esr1 expression in female mice

Di-(2-ethylhexyl)-phthalate (DEHP) is a phthalate ester that binds peroxisome proliferator-activated receptor α (PPARα) to induce proliferation of peroxisomes and regulate the expression of specific target genes. The question of whether the effect of DEHP on female reproductive processes is mediated via PPARα-dependent signaling is controversial. In this study, we investigated the effect of exposure to DEHP on ovarian expression of estrogen receptor α (Esr1) and aromatase (Cyp19a1) in three generations of Sv/129 wild-type (WT, +/+) and PPARα (-/-) knockout mice. Compared with untreated controls, ovarian expression of Esr1 decreased in response to DEHP treatment in the F0 (0.56-fold, P=0.19), F1 (0.45-fold, P=0.023), and F2 (0.35-fold, P=0.014) generations of WT mice, but not PPARα-null mice. Our data indicate that transgenerational repression by DEHP of ovarian Esr1 gene expression is mediated by PPARα-dependent pathways. Further studies are required to elucidate the mechanisms underlying crosstalk between PPARα and Esr1 signaling in reproductive processes.

Anogenital distance and its application in environmental health research

Anogenital distance (AGD), a useful anthropometric measurement for genital development in both animals and humans, was originally found by reproductive toxicologists in rodent experiments. As an easy-to-measure and sensitive marker, AGD has become a bioassay of fetal androgen action and a well-established reproductive toxicity endpoint in animals. It is generally accepted that AGD is sexually dimorphic in many mammals, with males having longer AGD than females. Exposure to proposed endocrine disruptors may result in reduced AGD; thus, it has been used to measure health effects of compounds with endocrine-altering properties or endocrine-disrupting chemicals (EDCs) in environmental toxicology. Moreover, AGD is an important clinical measure to address endocrine-sensitive endpoints in the first year of life and to assess the adverse impact of in utero exposure to environmental EDCs. Recently, AGD has been identified as one of the endpoints in the US Environmental Protection Agency guidelines for reproductive toxicity studies in humans, but use of AGD in human studies is still rare, and the results remain mixed and inconclusive due to many reasons. In order to achieve a breakthrough, researchers are endeavoring to standardize the measurement of AGD, normalize age-specific population data in different ethnic groups, and conduct more in-depth human researches in this field.

Temporal trends in phthalate exposures: findings from the National Health and Nutrition Examination Survey, 2001-2010

BACKGROUND

Phthalates are ubiquitous environmental contaminants. Because of potential adverse effects on human health, butylbenzyl phthalate [BBzP; metabolite, monobenzyl phthalate (MBzP)], di-n-butyl phthalate [DnBP; metabolite, mono-n-butyl phthalate (MnBP)], and di(2-ethylhexyl) phthalate (DEHP) are being replaced by substitutes including other phthalates; however, little is known about consequent trends in population-level exposures.

OBJECTIVE

We examined temporal trends in urinary concentrations of phthalate metabolites in the general U.S. population and whether trends vary by sociodemographic characteristics.

METHODS

We combined data on 11 phthalate metabolites for 11,071 participants from five cycles of the National Health and Nutrition Examination Survey (2001-2010). Percent changes and least square geometric means (LSGMs) were calculated from multivariate regression models.

RESULTS

LSGM concentrations of monoethyl phthalate, MnBP, MBzP, and ΣDEHP metabolites decreased between 2001-2002 and 2009-2010 [percent change (95% CI): -42% (-49, -34); -17% (-23, -9); -32% (-39, -23) and -37% (-46, -26), respectively]. In contrast, LSGM concentrations of monoisobutyl phthalate, mono(3-carboxypropyl) phthalate (MCPP), monocarboxyoctyl phthalate, and monocarboxynonyl phthalate (MCNP) increased over the study period [percent change (95% CI): 206% (178, 236); 25% (8, 45); 149% (102, 207); and 15% (1, 30), respectively]. Trends varied by subpopulations for certain phthalates. For example, LSGM concentrations of ΣDEHP metabolites, MCPP, and MCNP were higher in children than adults, but the gap between groups narrowed over time (pinteraction < 0.01).

CONCLUSIONS

Exposure of the U.S. population to phthalates has changed in the last decade. Data gaps make it difficult to explain trends, but legislative activity and advocacy campaigns by nongovernmental organizations may play a role in changing trends.

CITATION

Zota AZ, Calafat AM, Woodruff TJ. 2014. Temporal trends in phthalate exposures: findings from the National Health and Nutrition Examination Survey, 2001-2010. Environ Health Perspect 122:235-241; http://dx.doi.org/10.1289/ehp.1306681.

Variability and predictors of urinary concentrations of phthalate metabolites during early childhood

The variability and predictors of urinary concentrations of phthalate metabolites in preschool-aged children have not been thoroughly examined. Additionally, the impact of temporal changes in the use and restriction of phthalates in children's products has not been assessed. Our objective was to identify demographic, behavioral, and temporal predictors of urinary phthalate metabolite concentrations in young children. Between 2004 and 2011, we collected up to five urine samples from each of 296 children participating in a prospective birth cohort during annual study visits at ages 1-5 years. We used linear mixed models to calculate intraclass correlation coefficients (ICCs), a measure of within-individual reproducibility, and identify demographic predictors of urinary phthalate metabolites. We used multivariable linear regression to examine cross-sectional relationships between food packaging or personal care product use and phthalate metabolites measured at age 5 years. Across annual measurements, monoethyl phthalate exhibited the least variation (ICC = 0.38), while di-2-ethylhexyl phthalate (ΣDEHP) metabolites exhibited the most variation (ICC = 0.09). Concentrations changed with age, suggesting age-related changes in phthalate exposure and perhaps metabolism. Our findings suggest that fast food consumption may be a source of butylbenzyl phthalate and di-isononyl phthalate (DiNP) exposure, and some personal care products may be sources of diethyl phthalate exposure. Concentrations of ΣDEHP metabolites decreased over the study period; however, concentrations of DiNP metabolites increased. This finding suggests that manufacturer practices and regulations, like the Consumer Product Safety Improvement Act of 2008, may decrease DEHP exposure, but additional work characterizing the nature and toxicity of replacements is critically needed.

A survey of phthalates and parabens in personal care products from the United States and its implications for human exposure

Despite the widespread usage of phthalates and parabens in personal care products (PCPs), little is known about concentrations and profiles as well as human exposure to these compounds through the use of PCPs. In this study, nine phthalates and six parabens were determined in 170 PCPs (41 rinse-off and 109 leave-on), including 20 baby care products collected from Albany, New York. Phthalates were less frequently found in rinse-off PCPs but were more frequently found in perfumes (detection frequency of 100% for diethyl phthalate [DEP], 67% for dibutyl phthalate [DBP]), skin toners (90% for DEP), and nail polishes (90% for DBP). Parabens were found in ∼40% of rinse-off products and ∼60% of leave-on products. The highest concentrations of DEP, DBP, methyl- (MeP), ethyl- (EtP), propyl- (PrP), and butyl parabens (BuP) were on the order of 1000 μg per gram of the product. On the basis of amount and frequency of use of PCPs and the measured median concentrations of target analytes, the total dermal intake doses (sum of all phthalates or parabens) were calculated to be 0.37 and 31.0 μg/kg-bw/day for phthalates and parabens, respectively, for adult females. The calculated dermal intake of phthalates from PCPs was lower for infants and toddlers than for adult females. In contrast, dermal intake of parabens from PCPs by infants and toddlers was higher than that for adult females. The calculated maximum daily exposure dose of MeP, EtP, and PrP from PCPs ranged between 58.6 and 766 μg/kg-bw/day for infants and toddlers, which was 3 times higher than that calculated for adult females. PCPs are an important source of human exposure to parabens; the contribution of PCPs to phthalate exposure is low, except for DEP.