Association of Parental Preconception Exposure to Phthalates and Phthalate Substitutes With Preterm Birth

Paternal and maternal preconception and maternal pregnancy urinary concentrations of parabens in relation to child behavior

BACKGROUND

Epidemiologic studies of the effects of parental preconception paraben exposures on child behavior are limited despite emerging evidence suggesting that such exposures may affect offspring neurodevelopment.

OBJECTIVE

We investigated whether maternal and paternal preconception and maternal pregnancy urinary concentrations of parabens were associated with child behavior.

METHODS

We analyzed data from the Preconception Environmental exposure And Childhood health Effects Study, an ongoing prospective cohort of children aged 6-13 years and their parents. We estimated covariate-adjusted associations of loge-transformed urinary methyl, propyl, and butyl paraben concentrations (individually using linear regression models and as a mixture using quantile g-computation) collected prior to conception and during pregnancy with Behavioral Assessment System for Children-3 and Behavior Rating Inventory of Executive Function T-scores (higher scores indicate more problem behaviors).

RESULTS

This analysis included 140 mothers, 81 fathers, and 171 children (25 sets of twins); parents were predominantly non-Hispanic white (88% for both mothers and fathers). In single paraben models, higher paternal preconception urinary propyl and methyl paraben concentrations were associated with higher Internalizing Problem T-scores (propyl parabenβ $\beta \;$ = 1.7; 95% confidence interval: 0.6, 2.8, methyl parabenβ $\beta \;$ = 2.2; 95% confidence interval: 0.5, 3.9) and higher Behavioral Symptom Index T-scores (propyl parabenβ $\beta \;$ = 1.4; 95% confidence interval: 0.3, 2.5, methyl parabenβ $\beta \;$ = 1.6; 95% confidence interval: -0.1, 3.3). Each quantile increase in the paternal mixture of three parabens was associated with a 3.4 (95% confidence interval: 0.67, 6.1) and 2.5 (95% confidence interval: 0.01, 5.0) increased internalizing problem and Behavioral Symptom Index T-scores respectively. Higher paternal preconception (β $\beta \;$ = 1.0; 95% confidence interval: 0.04, 1.9) and maternal preconception (β $\beta \;$ = 1.1 95% confidence interval: -0.1, 2.2) concentrations of propyl paraben were associated with higher Behavior Rating Inventory of Executive Function Metacognition Index T-scores in children, but the paraben mixtures was not.

CONCLUSION

In this cohort, paternal preconception urinary concentrations of propyl and methyl paraben were associated with worse parent-reported child behaviors.

Effect of prenatal phthalate exposure on fetal development and maternal/neonatal health consequences: A systematic review

The ubiquitous presence of phthalate compounds in cosmetics, personal care products and plastics commonly used in toys, food packaging or household products, results in human exposure with adverse effects on reproductive health and fetal development. Following the PRISMA methodology, this systematic review analyzes the effect of prenatal phthalate exposure on major pregnancy complications, such as gestational diabetes, pregnancy-induced hypertension, fetal growth restriction and preterm birth, and its role in fetal neurodevelopment. This review includes >100 articles published in the last 10 years, showing an association between maternal exposure to phthalates and the risk of developing pregnancy complications. Phthalates are negatively associated with motor skills and memory, and also increase the risk of delayed language acquisition, autism spectrum disorder traits, and behavioral deficits, such as attention deficit hyperactivity disorder in children prenatally exposed to phthalates. Di (2-ethylhexyl) phthalate and its metabolites (mono(2-ethylhexyl) phthalate, mono(3-carboxypropyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate) are the main compounds associated with the above-mentioned pregnancy complications and fetal neurodevelopmental disorders. In addition, this review discusses the molecular mechanisms responsible for various pregnancy complications and neurodevelopmental disorders, and the critical window of exposure, in order to clarify these aspects. Globally, the most common molecular mechanisms involved in the effects of phthalates are endocrine disruption, oxidative stress induction, intrauterine inflammation, and DNA methylation disorders. In general, the critical window of exposure varies depending on the pathophysiology of the complication being studied, although the first trimester is considered an important period because some of the most vulnerable processes (embryogenesis and placentation) begin early in pregnancy. Future research should aim to understand the specific mechanism of the disruptive effect of each component and to establish the toxic dose of phthalates, as well as to elucidate the most critical period of pregnancy for exposure and the long-term consequences for human health.

Exploring associations between the Phthalate Environmental Reproductive Health Literacy (PERHL) scale & biomarkers of phthalate exposure: A pilot study

BACKGROUND

Perinatal exposure to phthalates is associated with adverse health impacts for parents and children. The field of environmental health literacy seeks to measure how environmental health information is conceptualized and used to inform behaviors. We assessed whether scores on the validated Phthalate Environmental Reproductive Health Literacy (PERHL) scale were associated with biomarkers of phthalate exposure.

METHODS

42 members of the Environmental Reproductive and Glucose Outcomes (ERGO) cohort completed the PERHL scale and provided spot urine samples. Phthalate summary measures for model outcomes were created by calculating molar sums of specific gravity-corrected metabolite concentrations representing exposure to parent phthalate, Di(2-ethylhexyl)phthalate (DEHP), personal care product (PCP)-associated phthalates, and parent butyl-phthalates. Linear regression models were used to estimate the associations of the PERHL scale scores with phthalate summary measures, controlling for educational attainment (college degree or higher vs. no college degree), age (years), and race and ethnicity (non-Hispanic White vs. non-White).

RESULTS

Higher scores on the PERHL Scale and subscales were generally associated with lower ΣDEHP, Σbutyl, and ΣPCP metabolite concentrations. A one-point increase in the 'Protective Behavior/Risk Control' subscale score was significantly associated with a -30.3% (95% CI: -50.1, -2.6) decrease in ΣDEHP, and a -30.6% (95% CI: -51.5, -0.63) decrease in Σbutyl metabolite concentrations.

Phthalate and DINCH exposure and ovarian reserve markers among women seeking infertility care

Phthalate exposure can adversely impact ovarian reserve, yet investigation on the influence of its alternative substance, the non-phthalate plasticizer diisononyl-cyclohexane-1,2-dicarboxylate (DINCH), on ovarian reserve is very sparce. We aimed to investigate the associations of phthalate and DINCH exposure as well as their combined mixture with ovarian reserve. This present study included 657 women seeking infertility care in Jiangsu, China (2015-2018). Urine samples during enrollment prior to infertility treatment were analyzed using high-performance liquid chromatography-isotope dilution tandem mass spectrometry (UPLC-MS/MS) to quantify 17 phthalate metabolites and 3 DINCH metabolites. Multivariate linear regression models, Poisson regression models and weighted quantile sum (WQS) regression were performed to access the associations of 17 urinary phthalate metabolites and 3 DINCH metabolites with ovarian reserve markers, including antral follicle count (AFC), anti-Mullerian hormone (AMH), and follicle-stimulating hormone (FSH). We found that the most conventional phthalates metabolites (DMP, DnBP, DiBP, DBP and DEHP) were inversely associated with AFC, and the DINCH metabolites were positively associated with serum FSH levels. The WQS index of phthalate and DINCH mixtures was inversely associated with AFC (% change = -8.56, 95 % CI: -12.63, -4.31) and positively associated with FSH levels (% change =7.71, 95 % CI: 0.21, 15.78). Our findings suggest that exposure to environmental levels of phthalate and DINCH mixtures is inversely associated with ovarian reserve.

Paternal DDT exposure induces sex-specific programming of fetal growth, placenta development and offspring's health phenotypes in a mouse model

Mounting evidence suggests that environmentally induced epigenetic inheritance occurs in mammals and that traits in the progeny can be shaped by parental environmental experiences. Epidemiological studies link parental exposure to environmental toxicants, such as the pesticide DDT, to health phenotypes in the progeny, including low birth and increased risk of chronic diseases later in life. Here, we show that the progeny of male mice exposed to DDT in the pre-conception period are born smaller and exhibit sexual dimorphism in metabolic function, with male, but not female, offspring developing severe glucose intolerance compared to controls. These phenotypes in DDT offspring were linked to reduced fetal growth and placenta size as well as placenta-specific reduction of glycogen levels and the nutrient sensor and epigenetic regulator OGT, with more pronounced phenotypes observed in male placentas. However, placenta-specific genetic reduction of OGT only partially replicates the metabolic phenotype observed in offspring of DDT-exposed males. Our findings reveal a role for paternal pre-conception environmental experiences in shaping placenta development and in fetal growth restriction. While many questions remain, our data raise the tantalizing possibility that placenta programming could be a mediator of environmentally induced intergenerational epigenetic inheritance of phenotypes and needs to be further evaluated.

Association of maternal phthalates exposure and metabolic gene polymorphisms with congenital heart diseases: a multicenter case-control study

BACKGROUND

The majority of congenital heart diseases (CHDs) are thought to result from the interactions of genetics and the environment factors. This study aimed to assess the association of maternal non-occupational phthalates exposure, metabolic gene polymorphisms and their interactions with risk of CHDs in offspring.

METHODS

A multicenter case-control study of 245 mothers with CHDs infants and 268 control mothers of health infant was conducted from six hospitals. Maternal urinary concentrations of eight phthalate metabolites were measured by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). Twenty single nucleotide polymorphisms (SNPs) in cytochrome P450 family 2 subfamily C member 9 (CYP2C9) and 19 (CYP2C19), uridine diphosphate (UDP) glucuronosyl transferase family 1 member A7 (UGT1A7), family 2 member B7 (UGT2B7) and B15(UGT2B15) genes were genotyped. The multivariate logistic regressions were used to estimate the association between maternal phthalates exposure or gene polymorphisms and risk of CHDs. Generalized multifactor dimensionality reduction (GMDR) was used to analyze the gene-gene and gene-phthalates exposure interactions.

RESULTS

There was no significant difference in phthalate metabolites concentrations between the cases and controls. No significant positive associations were observed between maternal exposure to phthalates and CHDs. The SNPs of UGT1A7 gene at rs4124874 (under three models, log-additive: aOR = 1.74, 95% CI:1.28-2.37; dominant: aOR = 1.86, 95% CI:1.25-2.78; recessive: aOR = 2.50, 95% CI: 1.26-4.94) and rs887829 (under the recessive model: aOR = 13.66, 95% CI: 1.54-121) were significantly associated with an increased risk of CHDs. Furthermore, the associations between rs4124874 (under log-additive and dominant models) of UGT1A7 were statistically significant after the false discovery rate correction. No significant gene-gene or gene-phthalate metabolites interactions were observed.

CONCLUSIONS

The polymorphisms of maternal UGT1A7 gene at rs4124874 and rs887829 were significantly associated with an increased risk of CHDs. More large-scale studies or prospective study designs are needed to confirm or refute our findings in the future.

Prenatal phthalate exposure and adverse birth outcomes in the USA: a prospective analysis of births and estimates of attributable burden and costs

BACKGROUND

Phthalates are synthetic chemicals widely used in consumer products and have been identified to contribute to preterm birth. Existing studies have methodological limitations and potential effects of di-2-ethylhexyl phthalate (DEHP) replacements are poorly characterised. Attributable fractions and costs have not been quantified, limiting the ability to weigh trade-offs involved in ongoing use. We aimed to leverage a large, diverse US cohort to study associations of phthalate metabolites with birthweight and gestational age, and estimate attributable adverse birth outcomes and associated costs.

METHODS

In this prospective analysis we used extant data in the US National Institutes of Health Environmental influences on Child Health Outcomes (ECHO) Program from 1998 to 2022 to study associations of 20 phthalate metabolites with gestational age at birth, birthweight, birth length, and birthweight for gestational age z-scores. We also estimated attributable adverse birth outcomes and associated costs. Mother-child dyads were included in the study if there were one or more urinary phthalate measurements during the index pregnancy; data on child's gestational age and birthweight; and singleton delivery.

FINDINGS

We identified 5006 mother-child dyads from 13 cohorts in the ECHO Program. Phthalic acid, diisodecyl phthalate (DiDP), di-n-octyl phthalate (DnOP), and diisononyl phthalate (DiNP) were most strongly associated with gestational age, birth length, and birthweight, especially compared with DEHP or other metabolite groupings. Although DEHP was associated with preterm birth (odds ratio 1·45 [95% CI 1·05-2·01]), the risks per log10 increase were higher for phthalic acid (2·71 [1·91-3·83]), DiNP (2·25 [1·67-3·00]), DiDP (1·69 [1·25-2·28]), and DnOP (2·90 [1·96-4·23]). We estimated 56 595 (sensitivity analyses 24 003-120 116) phthalate-attributable preterm birth cases in 2018 with associated costs of US$3·84 billion (sensitivity analysis 1·63- 8·14 billion).

INTERPRETATION

In a large, diverse sample of US births, exposure to DEHP, DiDP, DiNP, and DnOP were associated with decreased gestational age and increased risk of preterm birth, suggesting substantial opportunities for prevention. This finding suggests the adverse consequences of substitution of DEHP with chemically similar phthalates and need to regulate chemicals with similar properties as a class.

FUNDING

National Institutes of Health.

Influence of maternal endocrine disrupting chemicals exposure on adverse pregnancy outcomes: A systematic review and meta-analysis

Maternal endocrine disrupting chemicals (EDCs) exposure, the common environmental pollutants, was capable of involving in adverse pregnancy outcomes. However, the evidence of their connection is not consistent. Our goal was to comprehensively explore the risk of EDCs related to adverse pregnancy outcomes. One hundred and one studies were included from two databases before 2023 to explore the association between EDCs and adverse pregnancy outcomes including miscarriage, small for gestational age (SGA), low birth weight (LBW) and preterm birth (PTB). We found that maternal PFASs exposure was positively correlated with PTB (OR:1.13, 95% CI:1.04-1.23), SGA (OR:1.10, 95% CI:1.04-1.16) and miscarriage (OR:1.09, 95% CI:1.00-1.19). The pooled estimates also showed maternal PAEs exposure was linked with PTB (OR:1.16, 95% CI:1.11-1.21), SGA (OR:1.20, 95% CI:1.07-1.35) and miscarriage (OR:1.55, 95% CI:1.33-1.81). In addition, maternal exposure to some specific class of EDCs including PFOS, MBP, MEHP, DEHP, and BPA was associated with PTB. Maternal exposure to PFOS, PFOA, PFHpA was associated with SGA. Maternal exposure to BPA was associated with LBW. Maternal exposure to MMP, MEHP, MEHHP, MEOHP, BPA was associated with miscarriage. Maternal PFASs, PAEs and BPA exposure may increase adverse pregnancy outcomes risk according to our study. However, the limited number of studies on dose-response hampered further explanation for causal association.

Paternal and maternal preconception and maternal pregnancy urinary phthalate metabolite and BPA concentrations in relation to child behavior

BACKGROUND

Epidemiologic studies on health effects of parental preconception exposures are limited despite emerging evidence from toxicological studies suggesting that such exposures, including to environmental chemicals, may affect offspring health.

OBJECTIVE

We investigated whether maternal and paternal preconception and maternal pregnancy urinary phthalate metabolite and bisphenol A (BPA) concentrations were associated with child behavior.

METHODS

We analyzed data from the Preconception Environmental exposure And Childhood health Effects (PEACE) Study, an ongoing prospective cohort study of children aged 6-11 years whose parent(s) previously enrolled in the prospective preconception Environment and Reproductive Health (EARTH) study. Using linear mixed models, we estimated covariate-adjusted associations of 11 urinary phthalate metabolite and BPA concentrations collected prior to conception and during pregnancy with Behavioral Assessment System for Children-3 (BASC-3) T-scores (higher scores indicate more problem behaviors).

RESULTS

This analysis included 134 mothers, 87 fathers and 157 children (24 sets of twins); parents were predominantly non-Hispanic white (mothers and fathers86%). Higher maternal preconception or pregnancy monobenzyl phthalate (MBzP) concentrations were related to higher mean externalizing problems T-scores in their children (β = 1.3 per 1-loge unit increase; 95 % CI: -0.2, 2.4 and β = 2.1, 95 % CI: 0.7, 3.6, respectively). Higher maternal preconception monocarboxyoctyl phthalate (MCOP) was suggested to be related to lower mean externalizing problems T-scores (β = -0.9; 95 % CI: -1.8, 0.0). Higher paternal preconception MCOP was suggestively associated with lower internalizing problems (β = -0.9; 95 %CI:-1.9, 0.1) and lower Behavioral Symptoms Index (BSI) T-scores (β = -1.3; 95 % CI: -2.1, -0.4).

CONCLUSION

In this cohort, higher maternal preconception and pregnancy MBzP were associated with worse parent-reported child behavior, while higher maternal and paternal preconception MCOP concentrations were related to lower BASC-3 scores.

Associations of urinary non-persistent endocrine disrupting chemical biomarkers with early-to-mid pregnancy plasma sex-steroid and thyroid hormones

BACKGROUND/OBJECTIVES

Pregnant women are exposed to numerous endocrine disrupting chemicals (EDCs) that can affect hormonal pathways regulating pregnancy outcomes and fetal development. Thus, we evaluated overall and fetal sex-specific associations of phthalate/replacement, paraben, and phenol biomarkers with sex-steroid and thyroid hormones.

METHODS

Illinois women (n = 302) provided plasma for progesterone, estradiol, testosterone, free T4 (FT4), total T4 (TT4), and thyroid stimulating hormone (TSH) at median 17 weeks gestation. Women also provided up-to-five first-morning urine samples monthly across pregnancy (8-40 weeks), which we pooled to measure 19 phthalate/replacement metabolites (reflecting ten parent compounds), three parabens, and six phenols. We used linear regression to evaluate overall and fetal sex-specific associations of biomarkers with hormones, as well as weighted quantile sum and Bayesian kernel machine regression (BKMR) to assess cumulative associations, non-linearities, and chemical interactions.

RESULTS

In women of relatively high socioeconomic status, several EDC biomarkers were associated with select hormones, without cumulative or non-linear associations with progesterone, FT4, or TT4. The biomarker mixture was negatively associated with estradiol (only at higher biomarker concentrations using BKMR), testosterone, and TSH, where each 10% mixture increase was associated with -5.65% (95% CI: -9.79, -1.28) lower testosterone and -0.09 μIU/mL (95% CI: -0.20, 0.00) lower TSH. Associations with progesterone, testosterone, and FT4 did not differ by fetal sex. However, in women carrying females, we identified an inverted u-shaped relationship of the mixture with estradiol. Additionally, in women carrying females, each 10% increase in the mixture was associated with 1.50% (95% CI: -0.15, 3.18) higher TT4, whereas in women carrying males, the mixture was associated with -1.77% (95% CI: -4.08, 0.58) lower TT4 and -0.18 μIU/mL (95% CI: -0.33, -0.03) lower TSH. We also identified select chemical interactions.

CONCLUSION

Some biomarkers were associated with early-to-mid pregnancy hormones. There were some sex-specific and non-linear associations. Future studies could consider how these findings relate to pregnancy/birth outcomes.

The Role of Endocrine Disrupting Chemicals in Gestation and Pregnancy Outcomes

Endocrine disrupting chemicals (EDCs) are exogenous substances widely disseminated both in the environment and in daily-life products which can interfere with the regulation and function of the endocrine system. These substances have gradually entered the food chain, being frequently found in human blood and urine samples. This becomes a particularly serious issue when they reach vulnerable populations such as pregnant women, whose hormones are more unstable and vulnerable to EDCs. The proper formation and activity of the placenta, and therefore embryonic development, may get seriously affected by the presence of these chemicals, augmenting the risk of several pregnancy complications, including intrauterine growth restriction, preterm birth, preeclampsia, and gestational diabetes mellitus, among others. Additionally, some of them also exert a detrimental impact on fertility, thus hindering the reproductive process from the beginning. In several cases, EDCs even induce cross-generational effects, inherited by future generations through epigenetic mechanisms. These are the reasons why a proper understanding of the reproductive and gestational alterations derived from these substances is needed, along with efforts to establish regulations and preventive measures in order to avoid exposition (especially during this particular stage of life).

Association between early preterm birth and maternal exposure to fine particular matter (PM10): A nation-wide population-based cohort study using machine learning

Although preterm birth (PTB), a birth before 34 weeks of gestation accounts for only less than 3% of total births, it is a critical cause of various perinatal morbidity and mortality. Several studies have been conducted on the association between maternal exposure to PM and PTB, but the results were inconsistent. Moreover, no study has analyzed the risk of PM on PTB among women with cardiovascular diseases, even though those were thought to be highly susceptible to PM considering the cardiovascular effect of PM. Therefore, we aimed to evaluate the effect of PM10 on early PTB according to the period of exposure, using machine learning with data from Korea National Health Insurance Service (KNHI) claims. Furthermore, we conducted subgroup analysis to compare the risk of PM on early PTB among pregnant women with cardiovascular diseases and those without. A total of 149,643 primiparous singleton women aged 25 to 40 years who delivered babies in 2017 were included. Random forest feature importance and SHAP (Shapley additive explanations) value were used to identify the effect of PM10 on early PTB in comparison with other well-known contributing factors of PTB. AUC and accuracy of PTB prediction model using random forest were 0.9988 and 0.9984, respectively. Maternal exposure to PM10 was one of the major predictors of early PTB. PM10 concentration of 5 to 7 months before delivery, the first and early second trimester of pregnancy, ranked high in feature importance. SHAP value showed that higher PM10 concentrations before 5 to 7 months before delivery were associated with an increased risk of early PTB. The probability of early PTB was increased by 7.73%, 10.58%, or 11.11% if a variable PM10 concentration of 5, 6, or 7 months before delivery was included to the prediction model. Furthermore, women with cardiovascular diseases were more susceptible to PM10 concentration in terms of risk for early PTB than those without cardiovascular diseases. Maternal exposure to PM10 has a strong association with early PTB. In addition, in the context of PTB, pregnant women with cardiovascular diseases are a high-risk group of PM10 and the first and early second trimester is a high-risk period of PM10.

The Minderoo-Monaco Commission on Plastics and Human Health

Background

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy, and the earth's environment. These harms occur at every stage of the plastic life cycle, from extraction of the coal, oil, and gas that are its main feedstocks through to ultimate disposal into the environment. The extent of these harms not been systematically assessed, their magnitude not fully quantified, and their economic costs not comprehensively counted.

Goals

The goals of this Minderoo-Monaco Commission on Plastics and Human Health are to comprehensively examine plastics' impacts across their life cycle on: (1) human health and well-being; (2) the global environment, especially the ocean; (3) the economy; and (4) vulnerable populations-the poor, minorities, and the world's children. On the basis of this examination, the Commission offers science-based recommendations designed to support development of a Global Plastics Treaty, protect human health, and save lives.

Report Structure

This Commission report contains seven Sections. Following an Introduction, Section 2 presents a narrative review of the processes involved in plastic production, use, and disposal and notes the hazards to human health and the environment associated with each of these stages. Section 3 describes plastics' impacts on the ocean and notes the potential for plastic in the ocean to enter the marine food web and result in human exposure. Section 4 details plastics' impacts on human health. Section 5 presents a first-order estimate of plastics' health-related economic costs. Section 6 examines the intersection between plastic, social inequity, and environmental injustice. Section 7 presents the Commission's findings and recommendations.

Plastics

Plastics are complex, highly heterogeneous, synthetic chemical materials. Over 98% of plastics are produced from fossil carbon- coal, oil and gas. Plastics are comprised of a carbon-based polymer backbone and thousands of additional chemicals that are incorporated into polymers to convey specific properties such as color, flexibility, stability, water repellence, flame retardation, and ultraviolet resistance. Many of these added chemicals are highly toxic. They include carcinogens, neurotoxicants and endocrine disruptors such as phthalates, bisphenols, per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants, and organophosphate flame retardants. They are integral components of plastic and are responsible for many of plastics' harms to human health and the environment.Global plastic production has increased almost exponentially since World War II, and in this time more than 8,300 megatons (Mt) of plastic have been manufactured. Annual production volume has grown from under 2 Mt in 1950 to 460 Mt in 2019, a 230-fold increase, and is on track to triple by 2060. More than half of all plastic ever made has been produced since 2002. Single-use plastics account for 35-40% of current plastic production and represent the most rapidly growing segment of plastic manufacture.Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture. The two principal factors responsible for this pivot are decreasing global demand for carbon-based fuels due to increases in 'green' energy, and massive expansion of oil and gas production due to fracking.Plastic manufacture is energy-intensive and contributes significantly to climate change. At present, plastic production is responsible for an estimated 3.7% of global greenhouse gas emissions, more than the contribution of Brazil. This fraction is projected to increase to 4.5% by 2060 if current trends continue unchecked.

Plastic Life Cycle

The plastic life cycle has three phases: production, use, and disposal. In production, carbon feedstocks-coal, gas, and oil-are transformed through energy-intensive, catalytic processes into a vast array of products. Plastic use occurs in every aspect of modern life and results in widespread human exposure to the chemicals contained in plastic. Single-use plastics constitute the largest portion of current use, followed by synthetic fibers and construction.Plastic disposal is highly inefficient, with recovery and recycling rates below 10% globally. The result is that an estimated 22 Mt of plastic waste enters the environment each year, much of it single-use plastic and are added to the more than 6 gigatons of plastic waste that have accumulated since 1950. Strategies for disposal of plastic waste include controlled and uncontrolled landfilling, open burning, thermal conversion, and export. Vast quantities of plastic waste are exported each year from high-income to low-income countries, where it accumulates in landfills, pollutes air and water, degrades vital ecosystems, befouls beaches and estuaries, and harms human health-environmental injustice on a global scale. Plastic-laden e-waste is particularly problematic.

Environmental Findings

Plastics and plastic-associated chemicals are responsible for widespread pollution. They contaminate aquatic (marine and freshwater), terrestrial, and atmospheric environments globally. The ocean is the ultimate destination for much plastic, and plastics are found throughout the ocean, including coastal regions, the sea surface, the deep sea, and polar sea ice. Many plastics appear to resist breakdown in the ocean and could persist in the global environment for decades. Macro- and micro-plastic particles have been identified in hundreds of marine species in all major taxa, including species consumed by humans. Trophic transfer of microplastic particles and the chemicals within them has been demonstrated. Although microplastic particles themselves (>10 µm) appear not to undergo biomagnification, hydrophobic plastic-associated chemicals bioaccumulate in marine animals and biomagnify in marine food webs. The amounts and fates of smaller microplastic and nanoplastic particles (MNPs <10 µm) in aquatic environments are poorly understood, but the potential for harm is worrying given their mobility in biological systems. Adverse environmental impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified, human exposure to plastics and plastic-associated chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.

Human Health Findings

Coal miners, oil workers and gas field workers who extract fossil carbon feedstocks for plastic production suffer increased mortality from traumatic injury, coal workers' pneumoconiosis, silicosis, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer. Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of "fenceline" communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birth weight, asthma, childhood leukemia, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer.During use and also in disposal, plastics release toxic chemicals including additives and residual monomers into the environment and into people. National biomonitoring surveys in the USA document population-wide exposures to these chemicals. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Chemical-laden MNPs formed through the environmental degradation of plastic waste can enter living organisms, including humans. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Infants in the womb and young children are two populations at particularly high risk of plastic-related health effects. Because of the exquisite sensitivity of early development to hazardous chemicals and children's unique patterns of exposure, plastic-associated exposures are linked to increased risks of prematurity, stillbirth, low birth weight, birth defects of the reproductive organs, neurodevelopmental impairment, impaired lung growth, and childhood cancer. Early-life exposures to plastic-associated chemicals also increase the risk of multiple non-communicable diseases later in life.

Economic Findings

Plastic's harms to human health result in significant economic costs. We estimate that in 2015 the health-related costs of plastic production exceeded $250 billion (2015 Int$) globally, and that in the USA alone the health costs of disease and disability caused by the plastic-associated chemicals PBDE, BPA and DEHP exceeded $920 billion (2015 Int$). Plastic production results in greenhouse gas (GHG) emissions equivalent to 1.96 gigatons of carbon dioxide (CO2e) annually. Using the US Environmental Protection Agency's (EPA) social cost of carbon metric, we estimate the annual costs of these GHG emissions to be $341 billion (2015 Int$).These costs, large as they are, almost certainly underestimate the full economic losses resulting from plastics' negative impacts on human health and the global environment. All of plastics' economic costs-and also its social costs-are externalized by the petrochemical and plastic manufacturing industry and are borne by citizens, taxpayers, and governments in countries around the world without compensation.

Social Justice Findings

The adverse effects of plastics and plastic pollution on human health, the economy and the environment are not evenly distributed. They disproportionately affect poor, disempowered, and marginalized populations such as workers, racial and ethnic minorities, "fenceline" communities, Indigenous groups, women, and children, all of whom had little to do with creating the current plastics crisis and lack the political influence or the resources to address it. Plastics' harmful impacts across its life cycle are most keenly felt in the Global South, in small island states, and in disenfranchised areas in the Global North. Social and environmental justice (SEJ) principles require reversal of these inequitable burdens to ensure that no group bears a disproportionate share of plastics' negative impacts and that those who benefit economically from plastic bear their fair share of its currently externalized costs.

Conclusions

It is now clear that current patterns of plastic production, use, and disposal are not sustainable and are responsible for significant harms to human health, the environment, and the economy as well as for deep societal injustices.The main driver of these worsening harms is an almost exponential and still accelerating increase in global plastic production. Plastics' harms are further magnified by low rates of recovery and recycling and by the long persistence of plastic waste in the environment.The thousands of chemicals in plastics-monomers, additives, processing agents, and non-intentionally added substances-include amongst their number known human carcinogens, endocrine disruptors, neurotoxicants, and persistent organic pollutants. These chemicals are responsible for many of plastics' known harms to human and planetary health. The chemicals leach out of plastics, enter the environment, cause pollution, and result in human exposure and disease. All efforts to reduce plastics' hazards must address the hazards of plastic-associated chemicals.

Recommendations

To protect human and planetary health, especially the health of vulnerable and at-risk populations, and put the world on track to end plastic pollution by 2040, this Commission supports urgent adoption by the world's nations of a strong and comprehensive Global Plastics Treaty in accord with the mandate set forth in the March 2022 resolution of the United Nations Environment Assembly (UNEA).International measures such as a Global Plastics Treaty are needed to curb plastic production and pollution, because the harms to human health and the environment caused by plastics, plastic-associated chemicals and plastic waste transcend national boundaries, are planetary in their scale, and have disproportionate impacts on the health and well-being of people in the world's poorest nations. Effective implementation of the Global Plastics Treaty will require that international action be coordinated and complemented by interventions at the national, regional, and local levels.This Commission urges that a cap on global plastic production with targets, timetables, and national contributions be a central provision of the Global Plastics Treaty. We recommend inclusion of the following additional provisions:The Treaty needs to extend beyond microplastics and marine litter to include all of the many thousands of chemicals incorporated into plastics.The Treaty needs to include a provision banning or severely restricting manufacture and use of unnecessary, avoidable, and problematic plastic items, especially single-use items such as manufactured plastic microbeads.The Treaty needs to include requirements on extended producer responsibility (EPR) that make fossil carbon producers, plastic producers, and the manufacturers of plastic products legally and financially responsible for the safety and end-of-life management of all the materials they produce and sell.The Treaty needs to mandate reductions in the chemical complexity of plastic products; health-protective standards for plastics and plastic additives; a requirement for use of sustainable non-toxic materials; full disclosure of all components; and traceability of components. International cooperation will be essential to implementing and enforcing these standards.The Treaty needs to include SEJ remedies at each stage of the plastic life cycle designed to fill gaps in community knowledge and advance both distributional and procedural equity.This Commission encourages inclusion in the Global Plastic Treaty of a provision calling for exploration of listing at least some plastic polymers as persistent organic pollutants (POPs) under the Stockholm Convention.This Commission encourages a strong interface between the Global Plastics Treaty and the Basel and London Conventions to enhance management of hazardous plastic waste and slow current massive exports of plastic waste into the world's least-developed countries.This Commission recommends the creation of a Permanent Science Policy Advisory Body to guide the Treaty's implementation. The main priorities of this Body would be to guide Member States and other stakeholders in evaluating which solutions are most effective in reducing plastic consumption, enhancing plastic waste recovery and recycling, and curbing the generation of plastic waste. This Body could also assess trade-offs among these solutions and evaluate safer alternatives to current plastics. It could monitor the transnational export of plastic waste. It could coordinate robust oceanic-, land-, and air-based MNP monitoring programs.This Commission recommends urgent investment by national governments in research into solutions to the global plastic crisis. This research will need to determine which solutions are most effective and cost-effective in the context of particular countries and assess the risks and benefits of proposed solutions. Oceanographic and environmental research is needed to better measure concentrations and impacts of plastics <10 µm and understand their distribution and fate in the global environment. Biomedical research is needed to elucidate the human health impacts of plastics, especially MNPs.

Summary

This Commission finds that plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use, and disposal that pay little attention to sustainable design or safe materials and a near absence of recovery, reuse, and recycling are responsible for grave harms to health, widespread environmental damage, great economic costs, and deep societal injustices. These harms are rapidly worsening.While there remain gaps in knowledge about plastics' harms and uncertainties about their full magnitude, the evidence available today demonstrates unequivocally that these impacts are great and that they will increase in severity in the absence of urgent and effective intervention at global scale. Manufacture and use of essential plastics may continue. However, reckless increases in plastic production, and especially increases in the manufacture of an ever-increasing array of unnecessary single-use plastic products, need to be curbed.Global intervention against the plastic crisis is needed now because the costs of failure to act will be immense.

Early-life exposure to di (2-ethyl-hexyl) phthalate: Role in children with endocrine disorders

Di (2-ethyl-hexyl) phthalate (DEHP), one of endocrine-disrupting chemicals (EDCs), has widespread concern due to its serious health hazards. Exposure to DEHP in the early stage of life affects fetal metabolic and endocrine function, which even would cause genetic lesions. To date, it is widely believed that the increasing incidence of childhood obesity and diabetes in adolescents is related to the impact of DEHP on glucose and lipid homeostasis in children. However, there remains a knowledge gap to recognize these adverse effects. Thus, in this review, besides the exposure routes and levels of DEHP, we further outline the effects of early-life exposure to DEHP on children and potential mechanisms, focusing on the aspect of metabolic and endocrine homeostasis.

Assessing testicular germ cell DNA damage in the comet assay; introduction of a proof-of-concept

The in vivo comet assay is widely used to measure genotoxicity; however, the current OECD test guideline (TG 489) does not recommend using the assay to assess testicular germ cells, due to the presence of testicular somatic cells. An adapted approach to specifically assess testicular germ cells within the comet assay is certainly warranted, considering regulatory needs for germ cell-specific genotoxicity data in relation to the increasing global production of and exposure to potentially hazardous chemicals. Here, we provide a proof-of-concept to selectively analyze round spermatids and primary spermatocytes, distinguishing them from other cells of the testicle. Utilizing the comet assay recordings of DNA content (total fluorescence intensity) and DNA damage (% tail intensity) of individual comets, we developed a framework to distinguish testicular cell populations based on differences in DNA content/ploidy and appearance. Haploid round spermatid comets are identified through (1) visual inspection of DNA content distributions, (2) setting DNA content thresholds, and (3) modeling DNA content distributions using a normal mixture distribution function. We also describe an approach to distinguish primary spermatocytes during comet scoring, based on their high DNA content and large physical size. Our concept allows both somatic and germ cells to be analyzed in the same animal, adding a versatile, sensitive, rapid, and resource-efficient assay to the limited genotoxicity assessment toolbox for germ cells. An adaptation of TG 489 facilitates accumulation of valuable information regarding distribution of substances to germ cells and their potential for inducing germ cell gene mutations and structural chromosomal aberrations.

Association of Preterm Birth and Exposure to Endocrine Disrupting Chemicals

Several studies in recent years have shown that endocrine disrupting chemicals (EDCs) can exert deleterious effects within several systems of the human body, such as the immune, neurological, and reproductive systems, among others. This review aims to summarize the investigations into the effect of EDC exposure on reproductive systems, namely preterm birth (PTB), and the efforts that international organizations have made to curb the harmful results of EDC exposure. To gather information, PubMed was initially searched for relevant articles containing the following terms: endocrine disrupting chemicals; preterm birth. PubMed was subsequently used to identify articles discussing the association between preterm birth and specific EDC exposures (BPA; phthalates; organochlorine pesticides; organophosphate pesticides; lead; PBDE; preterm birth). Both searches, limited to articles published within the past 20 years, identified several publications that have examined the association between various EDCs and PTB. While the findings of the studies differed, collectively they revealed sufficient evidence of a potential association between EDC exposure and risk of PTB. Thus, international organizations such as the United Nations Environmental Programme (UNEP) and World Health Organization (WHO) should continue to limit EDC exposure across the globe and monitor levels among individuals of reproductive age.

Associations of individual and cumulative urinary phthalate and replacement biomarkers with gestational weight gain through late pregnancy

BACKGROUND/AIMS

Phthalates and their replacements are endocrine/metabolic disruptors that may impact gestational weight gain (GWG) - a pregnancy health indicator. We investigated overall and fetal sex-specific associations of individual and cumulative phthalate/replacement biomarkers with GWG.

METHODS

Illinois women (n = 299) self-reported their weight pre-pregnancy and at their final obstetric appointment before delivery (median 38 weeks). We calculated pre-pregnancy body mass index and gestational age-specific GWG z-scores (GWGz). We quantified 19 phthalate/replacement metabolites (representing 10 parent compounds) in pools of up-to-five first-morning urine samples, collected approximately monthly between 8 and 40 weeks gestation. We used linear regression, quantile-based g-computation (QGComp), and weighted quantile sum regression (WQSR) to evaluate associations of ten biomarkers (individual metabolites or parent molar-sums) individually or as mixtures (in interquartile range intervals) with GWGz. We evaluated associations in all women and stratified by fetal sex.

RESULTS

Individually, sums of metabolites of di(2-ethylhexyl) phthalate (ƩDEHP), di(isononyl) cyclohexane-1,2-dicarboxylate (ƩDiNCH), and di(2-ethylhexyl) terephthalate (ƩDEHTP) had consistent inverse associations with GWGz, and some associations were fetal sex-specific. When evaluating phthalates/replacements as a mixture, QGComp identified ƩDEHP, ƩDEHTP, and mono-(3-carboxypropyl) phthalate, along with sum of di(isononyl) phthalate metabolites (ƩDiNP) and monobenzyl phthalate as notable contributors to lower and higher GWGz, respectively, resulting in a marginal inverse joint association in all women (β: -0.29; 95% CI: -0.70, 0.12). In women carrying females, ƩDEHP contributed to the marginal inverse joint association (β: -0.54; 95% CI: -1.09, 0.03). However, there was no overall association in women carrying males (β: 0.00; 95% CI: -0.60, 0.59), which was explained by approximately equal negative (driven by ƩDEHTP) and positive (driven by ƩDiNP) partial associations. WQSR analyses consistently replicated these QGComp findings.

CONCLUSIONS

Biomarkers of phthalates/replacements were fetal sex-specifically associated with GWGz. Because ƩDEHTP contributed substantively to mixture associations, additional studies in pregnant women may be needed around this plasticizer replacement.

Association of phthalate exposure with low birth weight in couples conceiving naturally or via assisted reproductive technology in a prospective birth cohort

BACKGROUND

Few studies have investigated the adverse effects of preconception phthalate (PAE) exposure on birth weight in couples receiving assisted reproductive technology (ART) compared to naturally conceived newborns.

OBJECTIVES

We examined the association between parental preconception/prenatal urinary phthalate exposure and low birth weight (LBW) risk in couples who conceived using ART or naturally.

METHODS

From the Jiangsu Birth Cohort Study (China), we recruited 544 couples who conceived after infertility treatment and 940 couples who conceived naturally and gave birth to a singleton infant between November 2014 and December 2019. Seventeen metabolites of phthalate and three metabolites of phthalate alternatives were analyzed in parental spot urine samples. Clinical data were collected from medical records. We used generalized linear models, elastic net regression, Bayesian kernel machine regression, and quantile-based g-computation to examine the individual and joint effects of parental phthalate exposure on birth weight and LBW risk ratios (RR).

RESULTS

The relationship between parental phthalate exposure and birth weight was consistent between ART and natural conception. Maternal exposure to mono-ethyl phthalate and mono-carboxyisooctyl phthalate was associated with an increased risk of LBW in ART-conceived infants (RR = 1.27; 95 % confidence interval (CI): 1.03, 1.56; and RR = 1.31; 95 % CI: 1.03, 1.67, respectively). In contrast, in the spontaneously conceived infants, higher paternal prenatal concentrations of mono-benzyl phthalate and mono-carboxyisononyl phthalate were associated with a 40 % and 53 % increase in LBW risk, respectively. Exposure to PAE mixtures was associated with LBW in ART-conceived infants, with the effects primarily driven by di-ethyl phthalate, benzylbutyl phthalate, and di-isononyl phthalate metabolites. Sex-specific LBW was observed, with females appearing to be more susceptible than males.

CONCLUSIONS

Maternal preconception and paternal prenatal exposure to phthalates were associated with increased risk of LBW in infants. Compared with natural conception, ART-conceived fetuses were more sensitive to PAE mixtures, which requires further attention.

Lifestyle interventions to reduce endocrine-disrupting phthalate and phenol exposures among reproductive age men and women: A review and future steps

Non-persistent endocrine-disrupting chemicals (EDCs), including phthalates and phenols, are ubiquitous in both the environment and human body. A growing body of epidemiologic studies have identified concerning links between EDCs and adverse reproductive and developmental health effects. Despite consistent evidence, risk assessments and policy interventions often arrive late. This presents an urgent need to identify evidence-based interventions for implementation at both clinical and community levels to reduce EDC exposure, especially in susceptible populations. The reproductive life cycle (menarche to menopause for females and after pubertal onset for males) includes some of the most vulnerable periods to environmental exposures, such as the preconception and perinatal stages, representing a key window of opportunity to intervene and prevent unfavorable health outcomes. This review aims to synthesize and assess behavioral, dietary, and residential EDC-driven interventions to develop recommendations for subsequent, larger-scale studies that address knowledge-gaps in current interventions during the reproductive life cycle. We selected 21 primary interventions for evaluation, in addition to four supplemental interventions. Among these, accessible (web-based) educational resources, targeted replacement of (known) toxic products, and personalization of the intervention through meetings and support groups, were the most promising strategies for reducing EDC concentrations. However, we document a paucity of interventions to prevent phthalate and phenol exposures during the reproductive years, especially among men. Accordingly, we recommend additional, larger clinical and community-based intervention studies to reduce EDC exposure. Specifically, future intervention studies should focus on short-term, mid-, and long-term exposure reduction to phthalates and phenols. The latter, especially, is required for the development of clinical and public health guidelines to promote reproductive and developmental health globally.

Determinants of urinary phthalate biomarker concentrations in pre- and perimenopausal women with consideration of race

BACKGROUND/OBJECTIVES

Phthalates are endocrine disruptors in consumer plastics and personal care products. Our objectives were to identify determinants of phthalate biomarkers in women during the hormonally-sensitive midlife period, and to consider differences between non-Hispanic White and Black women.

METHODS

We used information from the Midlife Women's Health Study of pre- and peri-menopausal women from Baltimore, Maryland (enrolled 2006-2015). We collected sociodemographic/health information via baseline questionnaires or during clinic visits and measured nine phthalate metabolites in pools of 2-4 urines collected across one menstrual cycle. We calculated molar sums of metabolites to estimate exposure to di(2-ethylhexyl) phthalate (ΣDEHP), personal care product phthalates (ΣPCPs), and phthalates in plastics (ΣPlastics). Accounting for meaningful predictors from bivariable analyses, our multivariable linear regression models evaluated determinants of phthalate biomarkers in all women (n = 689), non-Hispanic White women only (n = 467), or non-Hispanic Black women only (n = 195).

RESULTS

In multivariable analyses of all women, those who were perimenopausal, widowed/divorced, non-Hispanic Black, with higher family income, with lower BMI, or who reported more frequent nausea had higher monoethyl phthalate (MEP) and ΣPCP. Non-Hispanic White women who were perimenopausal had lower mono-(3-carboxypropyl) phthalate (MCPP) and monobutyl phthalate (MBP), those who consume alcohol had higher mono-isobutyl phthalate (MiBP), and those with higher BMI had lower MEP and higher MCPP. Alternatively, widowed/divorced Black women had higher ΣDEHP, monobenzyl phthalate (MBzP), and ΣPlastics, whereas Black women with higher income had higher MEP and ΣPCP. Black women who described themselves as having "as much" physical activity as others or who reported a skin condition had lower MBzP and MCPP, respectively.

CONCLUSION

We identified important determinants of phthalate biomarkers in midlife women and observed some differences by race. Future studies could consider reasons for these differences when developing interventions to reduce phthalate disparities and related health effects.

Association of preconception mixtures of phenol and phthalate metabolites with birthweight among subfertile couples

Although parental preconception exposure to some phenols and phthalates have been associated with reduced birthweight, few studies have examined these chemicals as complex mixtures.

Association between exposures to phthalate metabolites and preterm birth and spontaneous preterm birth: A systematic review and meta-analysis

Emerging evidence from observational studies proves the association between preterm birth (PTB) and phthalate metabolites; however, such findings are inconsistent and inconclusive. This meta-analysis aimed to clarify this association by accessing the connection between 11 phthalate metabolites and PTB, and 6 phthalate metabolites and spontaneous PTB. The PubMed, Embase, and WOS (Web of Science) databases were searched up to July 2020. Seven prospective studies met the inclusion criteria. Pooled odds ratios (OR) with 95% confidence intervals (CIs) were calculated for risk estimation. Our results indicated that mono-n-butyl phthalate (MBP), sum of di-2-ethylhexyl phthalate (ΣDEHP), and mono 3- carboxypropyl phthalate (MCPP) significantly correlated with the risk of PTB (MBP: OR = 1.23, 95% CI = 1.05-1.45; ΣDEHP: OR = 1.21, 95% CI =1.01-1.44; MCPP: OR = 1.09, 95% CI = 1.00-1.19). Pooled results showed that spontaneous PTB was associated with higher urinary levels of mono-ethyl phthalate (MEP), MCPP, mono-isobutyl phthalate (MIBP), and MBP (MBP: OR = 1.27, 95% CI = 1.02-1.58; MEP: OR = 1.19, 95% CI = 1.01-1.40; MCPP: OR = 1.15, 95% CI = 1.02-1.30; MIBP: OR = 1.38, 95% CI = 1.12-1.71). Overall, we conclude that during pregnancy, MBP, ΣDEHP, and MCPP levels are associated positively with PTB. MBP, MEP, MCPP, and MIBP levels had increased odds of spontaneous PTB. No significant associations were observed between other phthalate metabolites and PTB or spontaneous PTB. Further research is needed to verify these findings and elucidate the association of phthalate levels and PTB.

Prenatal exposure to phthalates and peripheral blood and buccal epithelial DNA methylation in infants: An epigenome-wide association study

BACKGROUND

Prenatal exposure to phthalates has been associated with adverse health and neurodevelopmental outcomes. DNA methylation (DNAm) alterations may be a mechanism underlying these effects, but prior investigations of prenatal exposure to phthalates and neonatal DNAm profiles are limited to placental tissue and umbilical cord blood.

OBJECTIVE

Conduct an epigenome-wide association study (EWAS) of the associations between prenatal exposure to phthalates and DNAm in two accessible infant tissues, venous buffy coat blood and buccal epithelial cells (BECs).

METHODS

Participants included 152 maternal-infant pairs from the Alberta Pregnancy Outcomes and Nutrition (APrON) study. Maternal second trimester urine samples were analyzed for nine phthalate metabolites. Blood (n = 74) or BECs (n = 78) were collected from 3-month-old infants and profiled for DNAm using the Infinium HumanMethylation450 (450K) BeadChip. Robust linear regressions were used to investigate the associations between high (HMWPs) and low molecular weight phthalates (LMWPs) and change in methylation levels at variable Cytosine-phosphate-Guanine (CpG) sites in infant tissues, as well as the sensitivity of associations to potential confounders.

RESULTS

One candidate CpG in gene RNF39 reported by a previous study examining prenatal exposure to phthalates and cord blood DNAm was replicated. The EWAS identified 12 high-confidence CpGs in blood and another 12 in BECs associated with HMWPs and/or LMWPs. Prenatal exposure to bisphenol A (BPA) associated with two of the CpGs associated with HMWPs in BECs.

DISCUSSION

Prenatal exposure to phthalates was associated with DNAm variation at CpGs annotated to genes associated with endocrine hormone activity (i.e., SLCO4A1, TPO), immune pathways and DNA damage (i.e., RASGEF1B, KAZN, HLA-A, MYO18A, DIP2C, C1or109), and neurodevelopment (i.e., AMPH, NOTCH3, DNAJC5). Future studies that characterize the stability of these associations in larger samples, multiple cohorts, across tissues, and investigate the potential associations between these biomarkers and relevant health and neurodevelopmental outcomes are needed.

PM2.5-bound phthalates and phthalate substitutes in a megacity of southern China: spatioseasonal variations, source apportionment, and risk assessment

Plasticizers are ubiquitous pollutants in the environment, whereas few efforts have been made to elucidate their emission sources in the atmosphere. In this research, the spatioseasonal variations and sources of particle-bound (PM_2.5) phthalates (PAEs) and their substitutes (APs) at residential sites in seven districts and at four potential point-source sites across a megacity in South China were revealed. The total concentrations of PAEs ranging from 10.7 to 528 ng/m³ were substantially higher than those of APs (1.45.58.5 ng/m³). Significant spatial variations in the concentrations of the pollutants were observed, which were generally higher at the sites with intensive industrial activities and the point-source sites. Most atmospheric plasticizer levels peaked in summer, probably due to the temperature-promoted volatilization. Seven sources of plasticizers were identified by the positive matrix factorization (PMF) model. The sources in less industrialized districts are mainly associated with domestic and commercial emissions and with industry in the industrialized districts. Specifically, plastics and personal care products together contributed 60% of the plasticizers in the atmosphere of this city, followed by solvents and polyester industry sources. The incremental lifetime cancer risk of inhalation exposure to bis(2-ethylhexyl) phthalate in the study city is below the acceptable level. Relatively higher risks were found for residents living around sites with intensive industrial activities and around wastewater treatment plant.

Maternal exposure to endocrine disrupting chemicals (EDCs) and preterm birth: A systematic review, meta-analysis, and meta-regression analysis

Preterm birth is the second most common cause of death in children under 5 years of age. The etiology of preterm birth has not yet been elucidated. Although maternal exposure to endocrine disrupting chemicals (EDCs) may increase the risk for preterm birth, associations have not been confirmed. We performed a meta-analysis to elucidate the relationships between maternal exposure to EDCs and preterm birth. A systematic search of PubMed, Ovid-EMBASE, and the Cochrane Library (CENTRAL) for relevant published studies providing quantitative data on the association between maternal EDC exposure and preterm birth in humans was conducted in July 2021. To calculate the overall estimates, we pooled the adjusted regression coefficients with 95% confidence intervals (CIs) from each study by the inverse variance method. A total of 59 studies were included. The pooled results indicated that maternal exposure to metals (OR, 1.23; 95% CI, 1.17 to 1.29) and phthalates (OR, 1.31; 95% CI, 1.21 to 1.42) was related to an increased risk for preterm birth. Specifically, maternal exposure to lead, cadmium, chromium, copper and manganese appeared to be correlated with an elevated risk for preterm birth. Additionally, maternal exposure to monoethyl phthalate (MEP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), monobenzyl phthalate (MBzP), and di (2-ethylhexyl) phthalate (DEHP) was also associated with preterm birth. In conclusion, maternal exposure to metals and phthalates may increase the risk for preterm birth based on current evidence.

Phthalate and DINCH urinary concentrations across pregnancy and risk of preterm birth

Preconception and prenatal exposure to phthalates has been associated with an increased risk of preterm birth. However, it is unclear whether there are periods of heightened susceptibility during pregnancy. This prospective cohort study included 386 women undergoing fertility treatment who gave birth to a singleton infant during 2005 through 2018. Eleven phthalate metabolites were measured in spot urine samples collected at each trimester. In approximately 50% of participants, two metabolites of 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), a phthalate substitute, were also measured. The molar sum of four di(2-ethylhexyl) phthalate metabolites (∑DEHP) was calculated. We evaluated the associations of mean maternal biomarker concentrations with risk of preterm birth using modified log-binomial models and utilized multiple informant models to compare trimester-specific associations. We examined the relative biomarker concentration across gestation comparing women with preterm birth to women with term delivery using quadratic mixed model. The risk ratio for preterm birth associated with a one-unit increase in the natural log-transformed urinary concentrations of ∑DEHP (mean during pregnancy) was 1.21 (95% confidence interval (CI): 0.84, 1.72). In multiple informant models, these associations were strongest in the third trimester (RR = 1.51; 95% CI: 1.17, 1.95). Estimated mean ∑DEHP concentrations were higher among women with preterm than term delivery, especially late in gestation. Associations with preterm birth were also observed for each of the four individual DEHP metabolites. Detection of cyclohexane-1,2-dicarboxylic acid monocarboxyisooctyl ester (MCOCH), a metabolite of DINCH, appeared to be positively related to preterm birth. In this prospective cohort of subfertile couples, maternal ∑DEHP metabolite concentrations during pregnancy were associated with an increased risk of preterm birth, particularly during late gestation.

OUP accepted manuscript

Exposure to environmental toxicants during preconception has been shown to affect offspring health and epigenetic mechanisms such as DNA methylation are hypothesized to be involved in adverse outcomes. However, studies addressing the effects of exposure to environmental toxicants during preconception on epigenetic changes in gametes are limited. The objective of this study is to determine the effect of preconceptional exposure to a dioxin-like polychlorinated biphenyl (3,3',4,4',5-pentachlorobiphenyl [PCB126]) on DNA methylation and gene expression in testis. Adult zebrafish were exposed to 3 and 10 nM PCB126 for 24 h and testis tissue was sampled at 7 days postexposure for histology, DNA methylation, and gene expression profiling. Reduced representation bisulfite sequencing revealed 37 and 92 differentially methylated regions (DMRs) in response to 3 and 10 nM PCB126 exposures, respectively. Among them, 19 DMRs were found to be common between both PCB126 treatment groups. Gene ontology (GO) analysis of DMRs revealed that enrichment of terms such as RNA processing, iron-sulfur cluster assembly, and gluconeogenesis. Gene expression profiling showed differential expression of 40 and 1621 genes in response to 3 and 10 nM PCB126 exposures, respectively. GO analysis of differentially expressed genes revealed enrichment of terms related to xenobiotic metabolism, oxidative stress, and immune function. There is no overlap in the GO terms or individual genes between DNA methylation and RNA sequencing results, but functionally many of the altered pathways have been shown to cause spermatogenic defects.

Update about the disrupting-effects of phthalates on the human reproductive system

Phthalate esters are synthetic chemicals used in the plastic industry as plasticizers and consumable products. According to United Nations, about 400 million tons of plastic are produced every year. In parallel with increased production, the concerns about its effects on human health have increased because phthalates are endocrine-disrupting compounds. Humans are continuously exposed to phthalates through different routes of exposure. Experimental data have associated the phthalates exposure to adverse effects on development and reproduction in women (e.g., earlier puberty, primary ovarian insufficiency, endometriosis, preterm birth, or in vitro fertilization) and men (e.g., anogenital distance, cryptorchidism, hypospadias, and changes in adult reproductive function) although there is no consensus. Therefore, one question arises: could the increase in infertility be related to phthalates exposure? To answer this question, we aimed to assess the disrupting-effects of phthalates on the human reproductive system. For this, we reviewed the current literature based on epidemiological and experimental data and experimental studies in humans. The phthalate effects were discussed in a separate mode for female and male reproductive systems. In summary, phthalates induce toxicity in the reproductive system and human development. The increased plastic production may be related to the increase in human infertility.

Parental Preconception Exposures to Outdoor Neighbourhood Environments and Adverse Birth Outcomes: A Protocol for a Scoping Review and Evidence Map

Parental preconception exposures to built and natural outdoor environments could influence pregnancy and birth outcomes either directly, or via a range of health-related behaviours and conditions. However, there is no existing review summarising the evidence linking natural and built characteristics, such as air and noise pollution, walkability, greenness with pregnancy and birth outcomes. Therefore, the planned scoping review aims to collate and map the published literature on parental preconception exposures to built and natural outdoor environments and adverse pregnancy and birth outcomes. We will search electronic databases (MEDLINE, EMBASE, Scopus) to identify studies for inclusion. Studies will be included if they empirically assess the relationship between maternal and paternal preconception exposures to physical natural and built environment features that occur outdoors in the residential neighbourhood and adverse pregnancy and birth outcomes. Two reviewers will independently screen titles and abstracts, and then the full text. Data extraction and assessment of study quality will be performed by one researcher and checked by a second researcher. Results will be summarised in a narrative synthesis, with additional summaries presented as tables and figures. The scoping review will be disseminated via a peer-reviewed publication, at academic conferences, and published on a website.

Environmental impact on reproductive health and risk mitigating strategies

PURPOSE OF REVIEW

The purpose of this review is to increase awareness among reproductive health professionals and trainees about the impact of environmental toxicants and climate change on women's health and mitigation strategies at the individual, professional and governmental levels.

RECENT FINDINGS

Global health indicators reveal a meteoric rise of noncommunicable diseases over the past 50 years, which threaten reproductive health directly and indirectly. Evolutionary genetic mutations as contributors are unlikely in this timeframe, and environmental causes have been invoked. Notably, the past 75 years have witnessed marked increases in industrial chemical production, and global warming has rendered a 'climate crisis' with extreme temperatures and compromised food, water, and air quality. There is now strong experimental and epidemiologic evidence for endocrine disrupting chemicals and particulate matter and chemical components of air pollution in the pathophysiology of human reproductive disorders during development and across the lifespan, especially among vulnerable populations.

SUMMARY

Environmental impacts on fertility, pregnancy outcomes, childhood neurodevelopment, and reproductive tract development are significant, not widely appreciated, and may be preventable. In light of the evidence, education and advocating economical mitigations of toxic environmental chemicals and alternative energy strategies are imperatives to assure quality reproductive health for this and future generations.

Maternal phthalate urine concentrations, fetal growth and adverse birth outcomes. A population-based prospective cohort study

IMPORTANCE

Exposure to phthalates may affect fetal growth, but previous studies are inconsistent and have not explored the trimester-specific effects of phthalates on repeated measures of fetal growth.

OBJECTIVE

To assess the associations of maternal phthalate metabolites urine concentrations with fetal growth measures and birth outcomes and identify potential windows of vulnerability to exposure.

DESIGN

Population-based prospective cohort study, the Generation R Study (2002-2006). Data analysis was performed from November 2019 to June 2020.

SETTING

Rotterdam, the Netherlands.

PARTICIPANTS

1379 pregnant women.

EXPOSURES

Maternal phthalate metabolites urine concentrations in first, second and third trimester.

MAIN OUTCOMES AND MEASURES

Fetal head circumference, length and weight measured in the second and third trimester by ultrasound and at birth and preterm birth and small size for gestational age at birth.

RESULTS

Higher pregnancy-averaged phthalic acid, low molecular weight phthalate (LMWP), high molecular weight phthalate (HMWP) and di-2-ethylhexylphthalate (DEHP) concentrations tended to be associated with lower fetal weight SDS across gestation. The associations of phthalic acid and LMWP with fetal weight became stronger as pregnancy progressed (differences -0.08 (95% CI -0.14 to -0.02) SDS and -0.09 (95% CI -0.16 to -0.02) SDS at 40 weeks per interquartile range increase in phthalic acid and LMWP, respectively). Higher concentrations of specific LMWP, HMWP and DEHP metabolites were also associated with smaller head circumference and lower length SDS at birth and an increased risk of preterm birth and small size for gestational age at birth (p-values < 0.05). We observed differences by timing of exposure in these associations.

CONCLUSIONS AND RELEVANCE

Higher maternal phthalate metabolites urine concentrations seem to be related with fetal growth restriction and preterm birth. Phthalates may have trimester specific effects on fetal growth and birth outcomes. Further studies are needed to explore the underlying mechanisms and long-term consequences.

Parental preconception exposure to phenol and phthalate mixtures and the risk of preterm birth

BACKGROUND

Parental preconception exposure to select phenols and phthalates was previously associated with increased risk of preterm birth in single chemical analyses. However, the joint effect of phenol and phthalate mixtures on preterm birth is unknown.

METHODS

We included 384 female and 211 male (203 couples) participants seeking infertility treatment in the Environment and Reproductive Health (EARTH) Study who gave birth to 384 singleton infants between 2005 and 2018. Mean preconception urinary concentrations of bisphenol A (BPA), parabens, and eleven phthalate biomarkers, including di(2-ethylhexyl) phthalate (DEHP) metabolites, were examined. We used principal component analysis (PCA) with log-Poisson regression and Probit Bayesian Kernel Machine Regression (BKMR) with hierarchical variable selection to examine maternal and paternal phenol and phthalate mixtures in relation to preterm birth. Couple-based BKMR model was fit to assess couples' joint mixtures in relation to preterm birth.

RESULTS

PCA identified the same four factors for maternal and paternal preconception mixtures. Each unit increase in PCA scores of maternal (adjusted Risk Ratio (aRR): 1.36, 95%CI: 1.00, 1.84) and paternal (aRR: 1.47, 95%CI: 0.90, 2.42) preconception DEHP-BPA factor was positively associated with preterm birth. Maternal and paternal BKMR models consistently presented the DEHP-BPA factor with the highest group Posterior Inclusion Probability (PIP). BKMR models further showed that maternal preconception BPA and mono(2-ethyl-5-hydroxyhexyl) phthalate, and paternal preconception mono(2-ethylhexyl) phthalate were positively associated with preterm birth when the remaining mixture components were held at their median concentrations. Couple-based BKMR models showed a similar relative contribution of paternal (PIP: 61%) and maternal (PIP: 77%) preconception mixtures on preterm birth. We found a positive joint effect on preterm birth across increasing quantiles of couples' total mixture concentrations.

CONCLUSION

In this prospective cohort of subfertile couples, maternal BPA and DEHP, and paternal DEHP exposure before conception were positively associated with preterm birth. Both parental windows jointly contributed to the outcome. These results suggest that preterm birth may be a couple-based pregnancy outcome.

Determinants of phthalate exposure among a U.S.-based group of Latino workers

BACKGROUND

Phthalates are endocrine disrupting compounds linked to various adverse health effects. U.S. national biomonitoring data indicate that select minority subgroups may suffer disparate exposures to phthalates. Still, exposures and their respective determinants among these subgroups are not well characterized.

OBJECTIVE

We sought to examine determinants of phthalate exposure in a subsample of US-based Latino adults.

METHODS

We conducted a cross-sectional study on 94 Latino immigrant adults in Maryland. Participants were >18 years of age and working in a service-based industry. We administered an interviewer-administered questionnaire to capture information on potential exposure determinants (e.g., demographic characteristics, consumer product use, and workplace exposures and behaviors) and using HPLC/MS-MS we quantified concentrations of 9 urinary phthalate metabolites: monoethyl phthalate (MEP, diethyl phthalate metabolite); mono-n-butyl phthalate (MBP, di-n-butyl phthalate metabolite); mono-isobutyl phthalate (MiBP, di-isobutyl phthalate metabolite; monobenzyl phthalate (MBzP, benzylbutyl phthalate metabolite); molar sum of di-2-ethylhexyl phthalate or DEHP metabolites [mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECCP)]; and mono(3-carboxypropyl) phthalate (MCPP, a non-specific metabolite of several phthalates including di-n-butyl phthalate and di-n-octyl phthalate). DEHP was analyzed as the molar sum of four metabolites (ΣDEHP = MEHP + MEHHP + MECPP + MEOHP). Spearman correlations, Wilcoxon-Mann-Whitney, and Kruskal-Wallis tests were conducted to assess bivariate associations between metabolite concentrations and potential exposure determinants. Covariates associated with metabolites at p < 0.10 in bivariate analyses were included in multivariable linear regression models to assess the independent effects of predictors on metabolite concentrations.

RESULTS

Uncorrected median phthalate metabolite concentrations were lower in our study population (50% of samples ranged between 1.4 and 23.6 μg/L. While we observed some significant associations with select predictors in our bivariate analysis, select associations were attenuated in multivariable regression models. In our final multivariable linear regression models, we found that use of bleach (β = 1.15, 95%CI:0.30, 2.00) and consumption pasta/rice/noodles (β = 0.87, 95%CI: 0.27, 1.46) was positively associated with MBzP concentrations. MEP concentrations were inversely associated with use of furniture polish (β = -1.17, 95%CI: 2.21, -0.12) and use of scented dryer sheets (β = -1.08, 95%CI: 2.01, -0.14). Lastly, ΣDEHP concentrations were inversely associated with use of degreaser (ßDEHP = -0.65, 95%CI: 1.25, -0.05).

CONCLUSIONS

In this predominantly U.S.-based Central American subsample of adults, we observed lower metabolite concentrations than those previously reported in other U.S. studies and other countries. Our findings could be due, in part, to temporal trends in phthalate exposures and cultural differences related to exposure-related behaviors. While some exposure determinants were identified in our bivariate analyses, results from multivariable regression models did not provide clear results as many associations were attenuated. Environmental exposures may vary within minority subgroups and should be explored further in future studies to further inform exposure mitigation strategies.

Redesign your in-person course for online: Creating connections and promoting engagement for better learning

This spring, instructors moved their courses online in an emergency fashion as campuses were closed due to the pandemic. As colleges prepare for the next academic year, there is a need to provide flexible instruction that is more intentional for quality online learning. We taught two undergraduate courses online for the first time this spring and surveyed our students' reactions to the course experiences. From our experiences and student feedback, we identified design elements and activities that were beneficial in promoting student engagement, sense of connectivity, and learning. We describe four qualities for a successful transition to online learning: (a) big questions and core concepts; (b) peer groups including reflective writing; (c) outreach to broader scientific community; and (d) instructor's social presence in the class. Our experience gives us confidence that courses can be redesigned for online without compromising rigor or essential learning goals.

Use of Plastics with Hot Food among Saudi Pregnant Women Is Associated with Increased Concentrations of A1C, Thyroid-Stimulating Hormone, and Homocysteine and Decreased Concentrations of Vitamins and Minerals

Data regarding association between the use of plastics with hot food and levels of vitamins and minerals, and other biochemical parameters are lacking. Cross-sectional data for 740 healthy pregnant Saudi women were collected from 21 health care centres and 2 hospitals from Madinah, Saudi Arabia. Detailed data regarding the frequency of plastic use with hot food were collected, and laboratory analyses of thyroid-stimulating hormone (TSH), homocysteine (HCY), glycated A1C (A1C), and selected vitamins and minerals were also done. Daily use of plastics with hot food was frequently reported among young mothers (p = 0.002). Plastic use with hot food on a daily basis was positively associated with TSH, HCY, and A1C, while it was negatively associated with concentrations of vitamin E, zinc, and selenium. Future research should address the complex hormonal and metabolic abnormalities that are linked to the release of certain components associated with the use of plastics with hot food. Interventions are urgently needed to eliminate the use of plastics with hot food to prevent health complications that may result from the long-term use of these materials.