Association between phthalate exposure and asthma risk: A meta-analysis of observational studies

Early-life exposure to mixtures of endocrine-disrupting chemicals and a multi-domain health score in preschool children

BACKGROUND

Early-life exposure to endocrine-disrupting chemicals, such as phenols and phthalates, is suspected to impact various dimensions of child health. Using a multi-outcome approach, this study aimed to estimate their cumulative effect on the child cardiometabolic, respiratory and neurodevelopmental health.

METHODS

In 373 children of 3 years old from the SEPAGES cohort, a multi-domain health score was built from twenty-three health parameters. Fourteen metabolites of parabens, phenols, and phthalate/DINCH were measured several times during pregnancy (trimester 2 and 3) and infancy (2 and 12 months of age). Two mixture models, quantile g computation (q-gcomp) and Bayesian Kernel Machine Regression (BKMR), estimated associations between increased concentration of parabens, phenols, and phthalates/DINCH and the child health score.

RESULTS

Q-gcomp showed that the paraben mixture and the phthalate mixture were associated with a poorer health score (β = -0.11, 95% Confidence Interval (CI): -0.22, 0.00; β = -0.14, 95% CI: -0.27, -0.01, respectively), while no significant association was found for the mixture of phenols (β = -0.06, 95% CI: -0.18, 0.06). A trend for an association was observed between the whole mixture (parabens, phenols and phthalates combined) with a poorer health score (β = -0.14, 95% CI: -0.32, 0.04). Similar patterns of association, while subject to large uncertainty, have been observed with BKMR.

DISCUSSION

This study provides further evidence for the adverse health effects of early-life exposure to parabens and phthalates. Based on their potential impact on multiple areas of child health, public health policies targeting these chemical compounds are recommended.

One year respiratory and neurodevelopmental outcome of premature neonates after exposure to plasticizers in the neonatal intensive care unit - A prospective cohort study

BACKGROUND

Premature neonates have an increased risk of long-term effects, including impaired respiratory and neurodevelopment. During NICU admission, they are exposed to endocrine-disrupting phthalates and alternative plasticizers. The objective was to study the association between cumulative NICU-based plasticizer exposure and respiratory and neurodevelopmental outcome during the first year of life.

METHODS

Premature neonates (gestational age <31 weeks and/or birth weight <1500 g) were prospectively enrolled at the Antwerp University Hospital, Belgium. Outcome was assessed at 12 months corrected age, using the Bayley Scales of Infant and Toddler Development-III and validated questionnaires for respiratory outcome. Urinary concentrations of plasticizers' biomarkers were measured weekly during NICU stay. Weighted quantile sum regression was utilized to assess associations between plasticizer biomarkers' mixtures and outcome.

RESULTS

Exposure of premature neonates (n = 110) to specific plasticizer mixtures correlated with worse fine motor (ß -0.96; 95%-CI -1.76, -0.15; p = 0.02) and receptive language development (ß -0.77; 95%-CI -1.23, -0.32; p = 0.001), and better gross motor (ß 2.24; 95%-CI 0.62, 3.86; p = 0.01) and expressive language development (ß 1.50; 95%-CI 0.33, 2.67; p = 0.02). NICU exposure to different plasticizer mixtures was associated with eczema (aOR 3.12; 95%-CI 1.23, 9.11; p = 0.02), repeated ear infections (aOR 5.53; 95%-CI 1.87, 23.14; p = 0.01), and respiratory-related healthcare visits during the first year of life (aOR 8.50; 95%-CI 2.05-55.91; p = 0.01).

CONCLUSIONS

Cumulative NICU exposure to phthalates and alternative plasticizers was associated with increased respiratory morbidity and eczema during the first year of life. Exposure to specific plasticizer mixtures correlated with worse or better neurodevelopment at one year of age.

Personal care product use and risk of adult-onset asthma: findings from the Sister Study

BACKGROUND

Personal care products (PCPs) contain endocrine-disrupting chemicals (EDCs) linked to hormonally-sensitive diseases. Population studies have found associations between prenatal EDC exposure and childhood asthma; however, few have investigated adult-onset asthma.

OBJECTIVES

We investigated the associations between commonly used PCPs and the risk of adult-onset asthma in a prospective cohort study of U.S. women.

METHODS

We analyzed 39,408 participants from the Sister Study (2003-2009). The participants self-reported their usage frequency of 41 PCPs in the 12-month period before baseline. Latent classes were used to identify groups with similar usage patterns ('infrequent', 'moderate', 'frequent') within types of products ('beauty', 'everyday hair', 'hygiene', and 'skincare'). Multivariable Cox regression models were used to assess the associations between PCP use and incident adult-onset asthma.

RESULTS

Over an average 12.5-year follow-up, 1,774 incident asthma cases were identified. Compared to infrequent users, moderate (hazard ratio [HR]=1.21 (95% confidence interval (CI):1.07,1.37)) and frequent (HR=1.22 (95%CI:1.08,1.38)) users of beauty products had significantly higher asthma risk. Similar associations were observed for hygiene (moderate: HR=1.14 (95%CI:1.01,1.29) and frequent: HR=1.20 (95%CI:1.06,1.36)) and skincare products (moderate: HR=1.21 (95%CI:1.06,1.38) and frequent: HR=1.20 (95%CI:1.06,1.35)). Several individual everyday hair products (hair spray, hair styling gel/mousse, and pomade or hair grease) were positively associated with asthma risk, but associations were not detected for everyday hair latent classes.

DISCUSSION

Our findings suggest that PCP use potentially contributes to future risk of adult-onset asthma among women. These novel findings reinforce the need for regulation of PCPs and their components to reduce the burden of asthma.

The role of plastics in allergy, immunology, and human health: What the clinician needs to know and can do about it

The effects of plastics on human health include allergy, atopy, asthma, and immune disruption, but the consequences of chemicals used in plastic materials span nearly every organ system and age group as well. Behavioral interventions to reduce plastic chemical exposures have reduced exposure in low- and high-income populations, yet health care providers know little about plastic chemical effects and seldom offer steps to patients to limit exposure. Health care facilities also use many products that increase the risk of chemical exposures, particularly for at-risk populations such as children in neonatal intensive care units. Given that disparities in plastic chemical exposure are well documented, collaborative efforts are needed between scientists and health care organizations, to develop products that improve provider knowledge about chemicals used in plastic materials and support the use of safer alternatives in medical devices and other equipment.

Associations of environmental chemical exposures measured in personal silicone wristbands with sociodemographic factors, COVID-19 restrictions, and child respiratory health

BACKGROUND

Although human biomonitoring of environmental chemicals has been considered a gold standard, these methods can be costly, burdensome, and prone to unwanted sources of variability that may cause confounding. Silicone wristbands have recently emerged as innovative passive samplers for measuring personal exposures.

METHODS

In a pilot study from 2019 to 2021 involving 55 children aged 5-9 years in Seattle and Yakima, Washington, we utilized silicone wristbands to explore associations of sociodemographic variables and COVID-19-related restrictions, including school closures, with exposures to numerous chemicals including brominated and organophosphate ester (OPE) flame retardants, polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs), phthalates, and pesticides. We additionally conducted the first analysis testing silicone wristband chemicals as predictors of child wheeze, individually and in mixtures via logistic weighted quantile sum regression (WQS).

RESULTS

Among 109 semi-volatile organic compounds measured, we detected 40 in >60% of wristbands worn by children continuously for an average of 5 days. Chemicals were generally positively correlated, especially within the same class. Male sex and increasing age were linked with higher exposures across several chemical classes; Hispanic/Latino ethnicity was linked with higher exposures to some phthalates and OPEs. COVID-19 restrictions were associated with lower wristband concentrations of brominated and triaryl OPE flame retardants. Each one-decile higher WQS exposure index was suggestively associated with 2.11-fold [95% CI: 0.93-4.80] higher odds of child wheeze. Risk of child wheeze was higher per 10-fold increase in the PAH chrysene (RR = 1.93[1.07-3.49]), the pesticide cis-permethrin (3.31[1.23-8.91]), and di-isononyl phthalate (DINP) (5.40[1.22-24.0]) CONCLUSIONS: Our identification of demographic factors including sex, age, and ethnicity associated with chemical exposures may aid efforts to mitigate exposure disparities. Lower exposures to flame retardants during pandemic restrictions corroborates prior evidence of higher levels of these chemicals in school versus home environments. Future research in larger cohorts is needed to validate these findings.

Pilot study: Unveiling the impact of bisphenol A and phthalate exposure on women with asthma

Endocrine disruptors are considered estrogenic disruptors, and recent researches suggested that they may have a link to the severity of asthma. We aim to validate the correlation between endocrine disruptors and various clinical measurements of asthma, depending on the menopausal status. A pilot case-control study was performed in female asthmatic patients who visited allergy clinic in SMG-SNU Boramae Medical Center. Medical information and the urinary concentrations of 4 endocrine disruptors on their first visit were collected and analyzed: bisphenol A, mono (2-ethyl-5-hydroxyhexyl) phthalate, mono (2-ethyl-5-oxohexyl) phthalate, and mono-n-butyl phthalate. A total of 35 female participants enrolled in the study, including 20 asthmatic patients and 15 healthy controls. The average concentrations of urinary endocrine disruptors in patient and control group did not demonstrate significant differences. Twenty asthmatic patients were divided into 2 groups according to their menstrual state. Using the Spearman rank correlation test in premenopausal asthmatic patients (n = 7), we found negative correlations between urinary concentration of mono-n-butyl phthalate and asthma control test score, as well as postbronchodilator forced expiratory flow at 25% to 75% of forced vital capacity (P-value = .007 and .04, respectively). In contrast, it did not show any correlation with asthma control test or postbronchodilator forced expiratory flow at 25% to 75% of forced vital capacity (P-value = 1.00 and .74, respectively) in postmenopausal group (n = 13). Endocrine disruptors might have an impact on the decline of small airway function and asthma management among premenopausal, but not postmenopausal, female asthmatic patients.

Association between phthalate exposure and risk of allergic rhinitis in children: A systematic review and meta-analysis

Phthalates are ubiquitous in diverse environments and have been linked to a myriad of detrimental health outcomes. However, the association between phthalate exposure and allergic rhinitis (AR) remains unclear. To address this knowledge gap, we conducted a systematic review and meta-analysis to comprehensively evaluate the relationship between phthalate exposure and childhood AR risk. We searched the Cumulative Index to Nursing and Allied Health Literature, Excerpta Medica Database, and PubMed to collect relevant studies and estimated pooled odds ratios (OR) and 95% confidence intervals (CI) for risk estimation. Ultimately, 18 articles, including seven cross-sectional, seven case-control, and four prospective cohort studies, were selected for our systematic review and meta-analysis. Our pooled data revealed a significant association between di-2-ethylhexyl phthalate (DEHP) exposure in children's urine and AR risk (OR = 1.188; 95% CI = 1.016-1.389). Additionally, prenatal exposure to combined phthalates and their metabolites in maternal urine was significantly associated with the risk of childhood AR (OR = 1.041; 95% CI = 1.003-1.081), although specific types of phthalates and their metabolites were not significant. Furthermore, we examined environmental phthalate exposure in household dust and found no significant association with AR risk (OR = 1.021; 95% CI = 0.980-1.065). Our findings underscore the potential hazardous effects of phthalates on childhood AR and offer valuable insights into its pathogenesis and prevention.

An Umbrella Review of Meta-Analyses Evaluating Associations between Human Health and Exposure to Major Classes of Plastic-Associated Chemicals

Background: Epidemiological research investigating the impact of exposure to plastics, and plastic-associated chemicals, on human health is critical, especially given exponentially increasing plastic production. In parallel with increasing production, academic research has also increased exponentially both in terms of the primary literature and ensuing systematic reviews with meta-analysis. However, there are few overviews that capture a broad range of chemical classes to present a state of play regarding impacts on human health. Methods: We undertook an umbrella review to review the systematic reviews with meta-analyses. Given the complex composition of plastic and the large number of identified plastic-associated chemicals, it was not possible to capture all chemicals that may be present in, and migrate from, plastic materials. We therefore focussed on a defined set of key exposures related to plastics. These were microplastics, due to their ubiquity and potential for human exposure, and the polymers that form the matrix of consumer plastics. We also included plasticisers and flame retardants as the two classes of functional additive with the highest concentration ranges in plastic. In addition, we included bisphenols and per- and polyfluoroalkyl substances (PFAS) as two other major plastic-associated chemicals with significant known exposure through food contact materials. Epistemonikos and PubMed were searched for systematic reviews with meta-analyses, meta-analyses, and pooled analyses evaluating the association of plastic polymers, particles (microplastics) or any of the selected groups of high-volume plastic-associated chemicals above, measured directly in human biospecimens, with human health outcomes. Results: Fifty-two systematic reviews were included, with data contributing 759 meta-analyses. Most meta-analyses (78%) were from reviews of moderate methodological quality. Across all the publications retrieved, only a limited number of plastic-associated chemicals within each of the groups searched had been evaluated in relevant meta-analyses, and there were no meta-analyses evaluating polymers, nor microplastics. Synthesised estimates of the effects of plastic-associated chemical exposure were identified for the following health outcome categories in humans: birth, child and adult reproductive, endocrine, child neurodevelopment, nutritional, circulatory, respiratory, skin-related and cancers. Bisphenol A (BPA) is associated with decreased anoclitoral distance in infants, type 2 diabetes (T2D) in adults, insulin resistance in children and adults, polycystic ovary syndrome, obesity and hypertension in children and adults and cardiovascular disease (CVD); other bisphenols have not been evaluated. Phthalates, the only plasticisers identified, are associated with spontaneous pregnancy loss, decreased anogenital distance in boys, insulin resistance in children and adults, with additional associations between certain phthalates and decreased birth weight, T2D in adults, precocious puberty in girls, reduced sperm quality, endometriosis, adverse cognitive development and intelligence quotient (IQ) loss, adverse fine motor and psychomotor development and elevated blood pressure in children and asthma in children and adults. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) but not other flame retardants, and some PFAS were identified and are all associated with decreased birth weight. In general populations, PCBs are associated with T2D in adults and endometriosis, bronchitis in infants, CVD, non-Hodgkin's lymphoma (NHL) and breast cancer. In PCB-poisoned populations, exposure is associated with overall mortality, mortality from hepatic disease (men), CVD (men and women) and several cancers. PBDEs are adversely associated with children's cognitive development and IQ loss. PBDEs and certain PFAS are associated with changes in thyroid function. PFAS exposure is associated with increased body mass index (BMI) and overweight in children, attention deficit hyperactive disorder (ADHD) in girls and allergic rhinitis. Potential protective associations were found, namely abnormal pubertal timing in boys being less common with higher phthalate exposure, increased high-density lipoprotein (HDL) with exposure to mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and reduced incidence of chronic lymphocytic lymphoma (a subtype of NHL) with PCB exposure. Conclusions: Exposure to plastic-associated chemicals is associated with adverse outcomes across a wide range of human health domains, and every plastic-associated chemical group is associated with at least one adverse health outcome. Large gaps remain for many plastic-associated chemicals. Recommendations: For research, we recommend that efforts are harmonised globally to pool resources and extend beyond the chemicals included in this umbrella review. Priorities for primary research, with ensuing systematic reviews, could include micro- and nanoplastics as well as emerging plastic-associated chemicals of concern such as bisphenol analogues and replacement plasticisers and flame retardants. With respect to chemical regulation, we propose that safety for plastic-associated chemicals in humans cannot be assumed at market entry. We therefore recommend that improved independent, systematic hazard testing for all plastic-associated chemicals is undertaken before market release of products. In addition because of the limitations of laboratory-based testing for predicting harm from plastic in humans, independent and systematic post-market bio-monitoring and epidemiological studies are essential to detect potential unforeseen harms.

Recent Insights into the Environmental Determinants of Childhood Asthma

PURPOSE OF REVIEW

Ubiquitous environmental exposures, including ambient air pollutants, are linked to the development and severity of childhood asthma. Advances in our understanding of these links have increasingly led to clinical interventions to reduce asthma morbidity.

RECENT FINDINGS

We review recent work untangling the complex relationship between air pollutants, including particulate matter, nitrogen dioxide, and ozone and asthma, such as vulnerable windows of pediatric exposure and their interaction with other factors influencing asthma development and severity. These have led to interventions to reduce air pollutant levels in children's homes and schools. We also highlight emerging environmental exposures increasingly associated with childhood asthma. Growing evidence supports the present threat of climate change to children with asthma. Environmental factors play a large role in the pathogenesis and persistence of pediatric asthma; in turn, this poses an opportunity to intervene to change the course of disease early in life.

Ongoing exposure to endocrine disrupting phthalates and alternative plasticizers in neonatal intensive care unit patients

Due to endocrine disrupting effects, di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices, was restricted in the EU Medical Devices Regulation (EU MDR 2017/745) and gradually replaced by alternative plasticizers. Neonates hospitalized in the neonatal intensive care unit (NICU) are vulnerable to toxic effects of plasticizers. From June 2020 to August 2022, urine samples (n = 1070) were repeatedly collected from premature neonates (n = 132, 4-10 samples per patient) born at <31 weeks gestational age and/or <1500 g birth weight in the Antwerp University Hospital, Belgium. Term control neonates (n = 21, 1 sample per patient) were included from the maternity ward. Phthalate and alternative plasticizers' metabolites were analyzed using liquid-chromatography coupled to tandem mass spectrometry. Phthalate metabolites were detected in almost all urine samples. Metabolites of alternative plasticizers, di-(2-ethylhexyl)-adipate (DEHA), di-(2-ethylhexyl)-terephthalate (DEHT) and cyclohexane-1,2-dicarboxylic-di-isononyl-ester (DINCH), had detection frequencies ranging 30-95 %. Urinary phthalate metabolite concentrations were significantly higher in premature compared to control neonates (p = 0.023). NICU exposure to respiratory support devices and blood products showed increased phthalate metabolite concentrations (p < 0.001). Phthalate exposure increased from birth until four weeks postnatally. The estimated phthalate intake exceeded animal-derived no-effect-levels (DNEL) in 10 % of samples, with maximum values reaching 24 times the DNEL. 29 % of premature neonates had at least once an estimated phthalate intake above the DNEL. Preterm neonates are still exposed to phthalates during NICU stay, despite the EU Medical Devices Regulation. NICU exposure to alternative plasticizers is increasing, though currently not regulated, with insufficient knowledge on their hazard profile.

Subpopulations of children with multiple chronic health outcomes in relation to chemical exposures in the ECHO-PATHWAYS consortium

A multimorbidity-focused approach may reflect common etiologic mechanisms and lead to better targeting of etiologic agents for broadly impactful public health interventions. Our aim was to identify clusters of chronic obesity-related, neurodevelopmental, and respiratory outcomes in children, and to examine associations between cluster membership and widely prevalent chemical exposures to demonstrate our epidemiologic approach. Early to middle childhood outcome data collected 2011-2022 for 1092 children were harmonized across the ECHO-PATHWAYS consortium of 3 prospective pregnancy cohorts in six U.S. cities. 15 outcomes included age 4-9 BMI, cognitive and behavioral assessment scores, speech problems, and learning disabilities, asthma, wheeze, and rhinitis. To form generalizable clusters across study sites, we performed k-means clustering on scaled residuals of each variable regressed on study site. Outcomes and demographic variables were summarized between resulting clusters. Logistic weighted quantile sum regressions with permutation test p-values associated odds of cluster membership with a mixture of 15 prenatal urinary phthalate metabolites in full-sample and sex-stratified models. Three clusters emerged, including a healthier Cluster 1 (n = 734) with low morbidity across outcomes; Cluster 2 (n = 192) with low IQ and higher levels of all outcomes, especially 0.4-1.8-standard deviation higher mean neurobehavioral outcomes; and Cluster 3 (n = 179) with the highest asthma (92 %), wheeze (53 %), and rhinitis (57 %) frequencies. We observed a significant positive, male-specific stratified association (odds ratio = 1.6; p = 0.01) between a phthalate mixture with high weights for MEP and MHPP and odds of membership in Cluster 3 versus Cluster 1. These results identified subpopulations of children with co-occurring elevated levels of BMI, neurodevelopmental, and respiratory outcomes that may reflect shared etiologic pathways. The observed association between phthalates and respiratory outcome cluster membership could inform policy efforts towards children with respiratory disease. Similar cluster-based epidemiology may identify environmental factors that impact multi-outcome prevalence and efficiently direct public policy efforts.

Development of interpretable machine learning models associated with environmental chemicals to predict all-cause and specific-cause mortality：A longitudinal study based on NHANES

Limited information is available on potential predictive value of environmental chemicals for mortality. Our study aimed to investigate the associations between 43 of 8 classes representative environmental chemicals in serum/urine and mortality, and further develop the interpretable machine learning models associated with environmental chemicals to predict mortality. A total of 1602 participants were included from the National Health and Nutrition Examination Survey (NHANES). During 154,646 person-months of follow-up, 127 deaths occurred. We found that machine learning showed promise in predicting mortality. CoxPH was selected as the optimal model for predicting all-cause mortality with time-dependent AUROC of 0.953 (95%CI: 0.951-0.955). Coxnet was the best model for predicting cardiovascular disease (CVD) and cancer mortality with time-dependent AUROCs of 0.935 (95%CI: 0.933-0.936) and 0.850 (95%CI: 0.844-0.857). Based on clinical variables, adding environmental chemicals could enhance the predictive ability of cancer mortality (P < 0.05). Some environmental chemicals contributed more to the models than traditional clinical variables. Combined the results of association and prediction models by interpretable machine learning analyses, we found urinary methyl paraben (MP) and urinary 2-napthol (2-NAP) were negatively associated with all-cause mortality, while serum cadmium (Cd) was positively associated with all-cause mortality. Urinary bisphenol A (BPA) was positively associated with CVD mortality.

Phthalate exposure and risk of metabolic syndrome components: A systematic review

Metabolic syndrome is a cluster of conditions that increase the risk of cardiovascular disease, i.e. obesity, insulin resistance, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-c) levels and arterial hypertension. Phthalates are environmental chemicals which might influence the risk of the aforementioned disturbances, although the evidence is still controversial. The objective of this work was to synthesize the evidence on the association between human phthalate exposure and metabolic syndrome or any of its components. In this systematic review, the PRISMA guidelines were followed and the literature was search in PubMed, Web of Science and Scopus. Longitudinal and cross-sectional studies were included, the later only if a subclinical marker of disease was evaluated. The methodological quality was assessed with the Newcastle Ottawa Scale and a checklist for Analytical Cross-Sectional Studies developed in the Joanna Briggs Institute. A total of 58 articles were identified that showed high heterogenicity in the specific phthalates assessed, time-window of exposure and duration of follow-up. The quality of the studies was evaluated as high (n = 46, score >7 points) or medium (n = 12, score 4-6). The most frequently studied phthalates were DEHP-MEHP, MBzP and MEP. The evidence revealed a positive association between prenatal (in utero) exposure to most phthalates and markers of obesity in the offspring, but contradictory results when postnatal exposure and obesity were assessed. Moreover, postnatal phthalate exposure showed positive and very consistent associations with markers of diabetes and, to a lesser extent, with triglyceride levels. However, fewer evidence and contradictory results were found for HDL-c levels and markers of hypertension. The suggested mechanisms for these metabolic effects include transcription factor PPAR activation, antagonism of thyroid hormone function, antiandrogenic effects, oxidative stress and inflammation, and epigenetic changes. Nevertheless, as the inconsistency of some results could be related to differences in the study design, future research should aim to standardise the exposure assessment.

Individual and combined effects of phthalate metabolites on eczema in the United States population

Phthalates might trigger immune dysregulation. The relationship between a phthalate mixture exposure and eczema remains unclear. To address this research gap, four statistical models were used to investigate the individual, combined, and interaction relationships between monoesters of phthalates (MPAEs) and eczema, including the logistic regression, weighted quantile sum regression (WQS), quantile g computation (qg-computation), and bayesian kernel machine regression (BKMR). Moreover, subgroup analyses were performed by sex and age. After adjusting for all covariates, the logistic regression model suggested a positive correlation between mono-(3-carboxypropyl) phthalate (MCPP) and eczema. Subgroup analysis suggested that the effect of the MPAEs on eczema was predominantly present in men and children. In the WQS model, the joint effect of 11 MPAEs on eczema was marginally significant [odds ratio = 1.36, 95% confidence interval: 0.97-1.90]. Moreover, a positive association was observed between the combined exposure to 11 MPAEs and eczema in the BKMR model. MCPP and mono-(carboxynonyl) phthalate were the most substantial risk factors based on the results of WQS and qg-computation models. The exposure to a mixture of MPAEs may lead to an elevated prevalence of eczema in the United States population, with men and children being particularly vulnerable to their effects.

Association of phthalate exposure with pulmonary function in adults: NHANES 2007-2012

BACKGROUND

Epidemiological evidence for the adverse effect of phthalate exposure on respiratory health is on the rise, but cross-sectional studies regarding its effects on lung function are limited and contradictory, especially in adults.

OBJECTIVE

To assess the associations between individual and a mixture of urinary phthalate metabolites and adult pulmonary function in the United States, and to identify which ones were primarily responsible for impaired respiratory function.

METHODS

We obtained a cross-sectional data on 3788 adults aged 20 years and older from the National Health and Nutrition Examination Survey (2007-2012). Respiratory function was evaluated using spirometry, and phthalate exposure was assessed by measuring the levels of ten urinary phthalate metabolites. The effects of individual and mixed phthalate metabolites exposure on lung function were assessed using multivariate linear regression models and the repeated holdout weighted quantile sum (WQS) regression models, respectively, after adjusting for potential confounders including age, gender, family poverty income ratio, body mass index, and serum cotinine.

RESULTS

When modeled as continuous variables or quantiles, urinary phthalate metabolites, including mono-ethyl phthalate (MEP), mono-n-butyl phthalate, mono-iso-butyl phthalate, mono-benzyl phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-(3-carboxypropyl) phthalate, and mono-carboxyoctyl phthalate, were identified to be negatively associated with forced vital capacity in percent predicted values (ppFVC) and forced expiratory volume in the first second in percent predicted values (ppFEV1). In addition, per each decile increase in the WQS index, ppFVC (β = -2.87, 95% CI: -3.56, -2.08) and ppFEV1 (β = -2.53, 95% CI: -3.47, -1.54) declined significantly, primarily due to the contribution of MEP and MECPP. Furthermore, there were no significant interactions between co-exposure to urinary phthalate metabolites and each covariate.

CONCLUSION

Our findings reveal that urinary phthalate metabolites are significantly associated with adult respiratory decrements, with diethyl and di-(2-ethylhexyl) phthalate contributing the most to the impaired lung function.

Bisphenol and phthalate exposure during pregnancy and the development of childhood lung function and asthma. The generation R study

BACKGROUND

Fetal exposure to bisphenols and phthalates may lead to alterations in the respiratory and immune system development in children, and to adverse respiratory health. AIMTO STUDY: the associations of fetal bisphenols and phthalates exposure with lung function and asthma at age 13 years.

STUDY DESIGN

and Methods This study among 1020 children was embedded in a population-based prospective cohort study. We measured maternal urine bisphenol and phthalate concentrations in first, second and third trimester of pregnancy, and lung function by spirometry and asthma by questionnaires at age 13 years. Multivariable linear and logistic regression models were applied.

RESULTS

Maternal urine bisphenol and phthalate concentrations averaged during pregnancy were not associated with childhood lung function or asthma. Associations of maternal urine bisphenol and phthalate concentrations in specific trimesters with respiratory outcomes showed that one interquartile range increase in the natural log transformed maternal urine mono-isobutyl phthalate concentration in second trimester was associated with a higher FEV₁/FVC, but not with asthma, accounting for confounders and multiple-testing correction. Although there were associations of higher second trimester bisphenol S with a lower FVC and FEV₁ in boys and girls, and of higher first trimester bisphenol S with a decreased risk of asthma in boys and an increased risk of asthma in girls, these results did not remain significant after correction for multiple testing. Results were not modified by maternal history of asthma or atopy.

CONCLUSIONS

Maternal urine bisphenol and phthalate concentrations averaged or in specific trimesters during pregnancy were not strongly associated with childhood lung function and asthma at age 13 years. BPS, as a BPA substitute, tended to be associated with impaired lung function and altered risk of asthma, partly sex-dependent, but its strength was limited by a relatively low detection rate and should be queried in contemporary cohorts.

Cumulative Exposure to Phthalates and Their Alternatives and Associated Female Reproductive Health: Body Burdens, Adverse Outcomes, and Underlying Mechanisms

The global birth rate has recently shown a decreasing trend, and exposure to environmental pollutants has been identified as a potential factor affecting female reproductive health. Phthalates have been widely used as plasticizers in plastic containers, children's toys, and medical devices, and their ubiquitous presence and endocrine-disrupting potential have already raised particular concerns. Phthalate exposure has been linked to various adverse health outcomes, including reproductive diseases. Given that many phthalates are gradually being banned, a growing number of phthalate alternatives are becoming popular, such as di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), di(2-ethylhexyl) adipate (DEHA), and di(2-ethylhexyl) terephthalate (DEHTP), and they are beginning to have a wide range of environmental effects. Studies have shown that many phthalate alternatives may disrupt female reproductive function by altering the estrous cycle, causing ovarian follicular atresia, and prolonging the gestational cycle, which raises growing concerns about their potential health risks. Herein, we summarize the effects of phthalates and their common alternatives in different female models, the exposure levels that influence the reproductive system, and the effects on female reproductive impairment, adverse pregnancy outcomes, and offspring development. Additionally, we scrutinize the effects of phthalates and their alternatives on hormone signaling, oxidative stress, and intracellular signaling to explore the underlying mechanisms of action on female reproductive health, because these chemicals may affect reproductive tissues directly or indirectly through endocrine disruption. Given the declining global trends of female reproductive capacity and the potential ability of phthalates and their alternatives to negatively impact female reproductive health, a more comprehensive study is needed to understand their effects on the human body and their underlying mechanisms. These findings may have an important role in improving female reproductive health and in turn decreasing the number of complications during pregnancy.

Harmonized human biomonitoring in European children, teenagers and adults: EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014-2021)

As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants of three age groups: (i) 3,576 children aged 6-12 years, (ii) 3,117 teenagers aged 12-18 years and (iii) 4,102 young adults aged 20-39 years. The participants were recruited between 2014 and 2021 in 11-12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability and will give leverage to national policy makers for the implementation of targeted measures.

Di-(2-ethylhexyl) phthalate aggravates fine particulate matter-induced asthma in weanling mice due to T follicular helper cell-dependent response

Environmental pollutants fine particulate matter and di-(2-ethylhexyl) phthalate (DEHP) are believed to be the risk factors for childhood asthma. Allergic asthma is basically an immediate hypersensitivity mediated by IgE, the product of humoral immune response. T follicular helper cells (Tfh) have been newly identified as the crucial T helper cells for supporting B cells to produce immunoglobulins in humoral immunity. Tfh cells are therefore potentially to serve as the diagnostic marker and therapeutic target of immune diseases. In this study, we examined the joint effects of fine particulate matter and DEHP on the initiation and progression of asthma and explored the fundamental role of Tfh cells during the process. Weanling C57BL/6 mice (both sexes) were concurrently exposed to DEHP (intragastric administration at 300 μg/kg) and fine atmospheric particulate matter (mean particle diameter < 4 µm, PM4) (oropharyngeal instillation at 2 mg/kg) once every three days for 30 days (10 times). We found that DEHP displayed adjuvant effects to potentiate PM4 allergen-induced expansion of Tfh and plasma cells, production of serum IgE and IgG1, and occurrence of airway hyper-responsiveness and inflammation. Then PM4 and DEHP co-exposure was performed to Cd4 knock-out mice reconstituted with normal wild-type adoptive Tfh cells or non-Tfh cells. The results of immune adoptive transfusion indicated that the joint immunotoxic effects of PM4 and DEHP were dependent on Tfh cells. We further proved that DEHP could adjuvantly boost PM4-induced expression of BCL-6 and c-MAF and secretion of IL-13 and IL-4 in Tfh cells. In conclusion, these data suggest that DEHP metabolites act in an adjuvant-like manner to aggravate PM4 allergen-induced asthma based on anaphylactic IgE response, resulting from excessive IL-13 and IL-4 synthesized by abnormally differentiated Tfh cells.

Does Using Corsi-Rosenthal Boxes to Mitigate COVID-19 Transmission Also Reduce Indoor Air Concentrations of PFAS and Phthalates?

The COVID-19 pandemic brought new emphasis on indoor air quality. However, few studies have investigated the impact of air filtration, a COVID-mitigation approach, on indoor air concentrations of semivolatile organic compounds (SVOCs). Using a quasi-experimental design, we quantified the impact of a relatively low-cost "do-it-yourself" air filter (Corsi-Rosenthal Box; CR Box) on indoor air concentrations of 42 PFAS and 24 other SVOCs. We sampled air before (October-November 2021) and during (February-March 2022) deployment of CR Boxes in 17 rooms located in an occupied Providence, Rhode Island office building. We measured sound levels in rooms with CR Boxes operating and not operating. While CR Boxes were deployed, concentrations of seven PFAS (N-EtFOSE, N-EtFOSA, FBSA, PFBS, PFHxS, PFOS, PFNA) were 28-61% lower and concentrations of five phthalates (DMP, DEP, DiBP, BBzP, DCHP) were 29-62% lower. Concentrations of five PFAS and one phthalate increased 23-44% during the intervention period, but the 95% CI of most of these estimates included the null. Daytime sound levels increased 5.0 dB when CR Boxes were operating. These results indicate that CR Boxes reduced exposure to several lower-volatility phthalates and sulfonated PFAS previously reported to be found in office building materials and products, with potentially distracting increases in sound levels.

Associations between repeated measures of urinary phthalate metabolites and biomarkers of oxidative stress in a rural agricultural cohort of children with asthma

Phthalate exposure is widespread, and studies suggest an adverse relationship with asthma morbidity, including some support for oxidative stress as an underlying pathophysiological mechanism. Urinary phthalate metabolites have been associated with biomarkers of oxidative stress, but data are few in children diagnosed with asthma. We used participant data from the Home Air in Agriculture Pediatric Intervention Trial (HAPI) to examine longitudinal relationships between phthalates and oxidative stress in a cohort of Latino children with asthma residing in an agricultural community. We used linear mixed-effects models to estimate associations between 11 urinary phthalate metabolites (and one summed measure of di-2-ethylhexyl phthalate (DEHP) metabolites, ∑DEHP) and two urinary biomarkers of oxidative stress: a biomarker of lipid peroxidation via measure of 8-isoprostane and a biomarker of DNA/RNA oxidative damage via combined measure of 8-hydroxydeoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), and 8-hydroxyguanine. Seventy-nine participants provided 281 observations. In covariate-adjusted models, we observed significant positive relationships between all phthalate metabolites and 8-isoprostane, effect sizes ranging from a 9.3 % (95 % CI: 4.2 %-14.7 %) increase in 8-isoprostane for each 100 % increase (i.e., doubling) of mono-(carboxy-isooctyl) phthalate (MCIOP), to a 21.0 % (95 % CI: 14.3 %-28.2 %) increase in 8-isoprostane for each doubling of mono-n-butyl phthalate (MNBP). For each doubling of mono-(carboxy-isononyl) phthalate (MCINP) and mono-ethyl phthalate (MEP), the DNA/RNA oxidative damage biomarker increased by 6.0 % (95 % CI: 0.2 %-12.2 %) and 6.5 % (95 % CI: 1.4 %-11.9 %), respectively. In conclusion, we provide unique data suggesting phthalate exposure is positively associated with oxidative stress in children with asthma. Our repeat measures provide novel identification of a consistent effect of phthalates on oxidative stress in children with asthma via lipid peroxidation. Confirmation in future studies of children with asthma is needed to enhance understanding of the role of phthalates in childhood asthma morbidity.

Phthalate Exposures and Placental Health in Animal Models and Humans: A Systematic Review

Phthalates are ubiquitous compounds known to leach from the plastic products that contain them. Due to their endocrine-disrupting properties, a wide range of studies have elucidated their effects on reproduction, metabolism, neurodevelopment, and growth. Additionally, their impacts during pregnancy and on the developing fetus have been extensively studied. Most recently, there has been interest in the impacts of phthalates on the placenta, a transient major endocrine organ critical to maintenance of the uterine environment and fetal development. Phthalate-induced changes in placental structure and function may have significant impacts on the course of pregnancy and ultimately, child health. Prior reviews have described the literature on phthalates and placental health; however to date, there has been no comprehensive, systematic review on this topic. Here, we review 35 papers (24 human and 11 animal studies) and summarize phthalate exposures in relation to an extensive set of placental measures. Phthalate-related alterations were reported for placental morphology, hormone production, vascularization, histopathology, and gene/protein expression. The most consistent changes were observed in vascular and morphologic endpoints, including cell composition. These changes have implications for pregnancy complications such as preterm birth and intrauterine growth restriction as well as potential ramifications for children's health. This comprehensive review of the literature, including common sources of bias, will inform the future work in this rapidly expanding field.

Are Phthalate Exposure Related to Oxidative Stress in Children and Adolescents with Asthma? A Cumulative Risk Assessment Approach

Childhood asthma has become one of the most common chronic diseases in children and adolescents. However, few case–control studies investigating the relationship between phthalate exposure and asthma in children and adolescents have been conducted, especially in Asia. Therefore, we assessed the potential associations between phthalate exposure and asthma among children and adolescents in Taiwan. Because various demographic and environmental variables may influence the incidence and prognosis of asthma, we performed a case–control study with propensity score matching. Out of 615 Childhood Environment and Allergic Diseases Study participants, we conditionally matched 41 children with clinically diagnosed asthma with 111 controls. We then analyzed 11 phthalate metabolites by using liquid chromatography with tandem mass spectrometry. Compared with the control group, the median urinary phthalate levels for most phthalate metabolites in the case group were slightly increased, including monomethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, monoethylhexyl phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, and mono-(2-carboxymethylhexyl) phthalate. Hence, our results suggest that phthalate exposure may be associated with the development of asthma. In addition, prenatal environmental factors, such as active or passive smoking during pregnancy, may increase the risk of asthma.

Longitudinal measures of phthalate exposure and asthma exacerbation in a rural agricultural cohort of Latino children in Yakima Valley, Washington

Phthalates are a class of widely used synthetic chemicals found in commonly used materials and products. Epidemiological studies suggest phthalate exposure is associated with asthma outcomes, though most studies have not investigated phthalates as triggers of exacerbations in children diagnosed with asthma. This study used data from the Home Air in Agriculture Pediatric Intervention Trial (HAPI) to examine relationships between phthalate exposure and outcomes related to childhood asthma exacerbation. We used measures of phthalate metabolites and respiratory health measures including fractional exhaled nitric oxide (FENO), the Asthma Control Test (ACT), caregiver report of symptoms, and urinary leukotriene E₄ (uLTE₄) to estimate longitudinal associations using mixed effects models, adjusted for covariates. For 100% (i.e., doubling) increases in mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-2-ethylhexyl phthalate (MEHP), and mono-ethyl phthalate (MEP), concentrations of FENO increased by 8.7% (95% CI: 0.7-17.3), 7.2% (95% CI: 0.0-14.9), and 6.4% (95% CI: 0.0-13.3), respectively. All phthalate metabolites demonstrated associations with uLTE₄, effect sizes ranging from an 8.7% increase in uLTE₄ (95% CI: 4.3-12.5) for a 100% increase in MEHP to an 18.1% increase in uLTE₄ (95% CI: 13.3-23.1) for a 100% increase in MNBP. In models of caregiver report of symptoms, no phthalate metabolites were significantly associated in primary models. No phthalate metabolites were associated with standardized ACT score. Our results suggest urinary phthalate metabolites are significant predictors of inflammatory biomarkers related to asthma exacerbation in children but not child and caregiver report of airway symptomatology.

Prenatal phthalate exposure and early childhood wheeze in the SELMA study

BACKGROUND

Prenatal maternal phthalate exposure has been associated with wheeze and asthma in children, but results are inconclusive. Previous studies typically assessed exposure in late pregnancy, included only a small number of old phthalates, and assessed outcomes in children aged 5 years or older.

OBJECTIVE

We explored associations between 1st trimester prenatal maternal exposure to a wider range of phthalates and wheeze in early childhood.

METHODS

First trimester concentrations of 14 metabolites from 8 phthalates and one alternative plasticizer were quantified in first-morning void urine from 1148 mothers in the Swedish SELMA study. Associations between log-transformed metabolite concentrations and parental reported ever wheeze among 24-month-old children were investigated with logistic regression models adjusted for parental asthma/rhinitis, sex of child, maternal education, smoking, and creatinine.

RESULTS

Metabolites of replacement phthalates di-iso-decyl phthalate (DiDP) and di-2-propylheptyl phthalate (DPHP) were associated with increased risk for wheeze (aOR 1.47, 95% CI 1.08-2.01 and aOR 1.49, 95% CI 1.04-2.15, respectively). The associations with DiDP and DPHP were stronger among children whose parents did not have asthma or rhinitis. In this group, wheeze was also associated with metabolites of butyl-benzyl phthalate (BBzP) and di-iso-nonyl phthalate (DiNP).

SIGNIFICANCE

Maternal phthalate exposure during early pregnancy may be a risk factor for wheeze in early childhood, especially among children whose parents do not have asthma or rhinitis symptoms.

Phthalate exposure and risk of diabetes mellitus: Implications from a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies indicated that phthalate exposure might be associated with diabetes mellitus (DM). However, discrepancies existed. The link between phthalate exposure and risk of DM remained unclarified.

METHODS

We conducted a meta-analysis to explore the association between phthalate exposure and risk of DM. Effects of phthalate exposure on insulin resistance were also evaluated by systematic review.

RESULTS

Seven studies involving 12,139 participants were included in this meta-analysis. Our results showed that urinary concentrations of phthalates were positively associated with risk of DM. The pooled ORs were 3.11 (95% CI: 1.16-8.37) for monomethyl phthalate (MMP), 1.27 (95% CI: 1.03-1.56) for mono-n-butyl phthalate (MnBP), 2.59 (95% CI: 1.10-6.10) for mono-isobutyl phthalate (MiBP), 1.99 (95% CI: 1.52-2.61) for mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), 1.90 (95% CI: 1.40-2.57) for mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), 1.55 (95% CI: 1.10-2.20) for mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), and 2.39 (95% CI: 1.18-4.85) for mono-(3-carboxypropyl) phthalate (MCPP), respectively. Molar summation of di-2-ethylhexyl phthalate metabolites (∑DEHP) was also found to be correlated with risk of DM (OR 2.15, 95% CI: 1.48-3.13). No significant association with risk of DM was found regarding monoethyl phthalate (MEP), monobenzyl phthalate (MBzP) and mono(2-ethylhexyl) phthalate (MEHP). In literature review, most studies showed positive correlations of phthalates, especially ∑DEHP, with homeostasis model assessment of insulin resistance and fasting glucose.

CONCLUSION

Exposure to phthalates, especially MMP, MnBP, MiBP, MCPP and DEHP metabolites, might be a risk factor of DM. Our results should be interpreted with caution due to heterogeneous design of enrolled studies.

Buy-now-pay-later: Hazards to human and planetary health from plastics production, use and waste

More than 8 billion tonnes of plastic were produced between 1950 and 2015, that is 1 tonne for every man, woman and child on our planet. Global plastic production has been growing exponentially with an annual growth rate of 8.4% since 1950, equating to approximately 380 million tonnes per annum. A further 50 kg of plastic is now being produced for each person every year with production continuing to accelerate. Here, we discuss the human and planetary health hazards of all that plastic. We consider each step in the journey of these complex and pervasive industrial materials: from their synthesis predominantly from fossil fuel feedstocks, through an often-brief consumer use as plastic products, and onto waste streams as fuel, permanent landfill or as unmanaged waste in our environment, food, air and bodies.

Association between environmental exposure to phthalates and allergic disorders in Korean children: Korean National Environmental Health Survey (KoNEHS) 2015-2017

BACKGROUND

Phthalates are common industrial chemicals that are used as plasticizers in plastics, personal care products, and building materials. Although these chemicals have been suspected as risk factors for allergic outcomes among children, inconsistent associations between environmental exposure to phthalates and allergic disorders have been found across different populations. Therefore, this study aimed to assess whether environmental phthalate exposure was associated with parent-reported current allergic symptoms (atopic dermatitis, AD; asthma; and allergic rhinitis, AR) and the index of allergic response (levels of serum total immunoglobulin E, IgE) in a nationally representative sample of children.

METHODS

In this study, children aged 3-17 years (n = 2208) were recruited from the Korean National Environmental Health Survey (KoNEHS) 2015-2017 to conduct an analysis of their current allergic symptoms. Among this number of children, the total IgE analysis included 806 participants because total IgE levels were only measured in children aged 12-17 years.

RESULTS

After adjusting for all covariates, mono-benzyl phthalate (MBzP) [OR (95% CI) = 1.15 (1.01, 1.30)], mono-(carboxyoctyl) phthalate (MCOP) [OR (95% CI) = 1.35 (1.02, 1.78)], and the sum of di-(2-ethylhexyl) phthalate metabolites (∑DEHP) [OR (95% CI) = 1.39 (1.09, 1.79)] were associated with increased odds of current AD. MCOP [OR (95% CI) = 1.19 (1.01, 1.40)], mono-(carboxynonyl) phthalate (MCNP) [OR (95% CI) = 1.24 (1.05, 1.45)], and ∑DEHP [OR (95% CI) = 1.22 (1.02, 1.44)] were also associated with increased odds of current AR. Individual DEHP metabolites showed similar associations with current AD and AR. In addition, MCNP was positively related to IgE levels [β (95% CI) = 0.26 (0.12, 0.40)]. MBzP [OR (95% CI) = 1.17 (1.01, 1.35)], MCOP [OR (95% CI) = 1.62 (1.12, 2.32)], and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) [OR (95% CI) = 1.36 (1.06, 1.76)] showed positive relationships with allergic multimorbidity. Moreover, higher concentrations of MCNP were related to increased odds of experiencing both current AR and total IgE levels [OR (95% CI) = 1.98 (1.29, 3.04)], and children with elevated IgE levels (>100IU/mL) were more likely to have current AR associated with MCNP than those without elevated IgE levels (p = 0.007). Specifically, the relationship between MCNP and current AR was significantly mediated through alterations in IgE levels (14.7%), and MCNP also showed the positive association with current AR, independent of IgE (85.3%).

CONCLUSION

These results suggest that environmental exposure to phthalates may affect the immune system and increase the occurrence of allergic symptoms in children.

Immune cell profiles associated with measured exposure to phthalates in the Norwegian EuroMix biomonitoring study - A mass cytometry approach in toxicology

BACKGROUND

Phthalate exposure has been associated with immune-related diseases such as asthma and allergies, but there is limited knowledge on mechanisms, effect biomarkers and thus biological support of causality.

OBJECTIVES

To investigate associations between exposure to the phthalates DEHP (di(2-ethylhexyl) phthalate) and DiNP (diisononyl phthalate) and functional immune cell profiles.

METHODS

Peripheral blood mononuclear cells (PBMCs) from 32 healthy adult Norwegian participants in the EuroMix biomonitoring study were selected based on high or low (n = 16) levels of urine metabolites of DEHP and DiNP. High-dimensional immune cell profiling including phenotyping and functional markers was performed by mass cytometry (CyTOF) using two broad antibody panels after PMA/ionomycin-stimulation. The CITRUS algorithm with unsupervised clustering was used to identify group differences in cell subsets and expression of functional markers, verified by manual gating.

RESULTS

The group of participants with high phthalate exposure had a higher proportion of some particular innate immune cells, including CD11c positive NK-cell and intermediate monocyte subpopulations. The percentage of IFNγ TNFα double positive NK cells and CD11b expression in other NK cell subsets were higher in the high exposure group. Among adaptive immune cells, however, the percentage of IL-6 and TNFα expressing naïve B cell subpopulations and the percentage of particular naïve cytotoxic T cell populations were lower in the high exposure group.

DISCUSSION

Cell subset percentages and expression of functional markers suggest that DEHP and DiNP phthalate exposure may stimulate subsets of innate immune cells and suppress adaptive immune cell subsets. By revealing significant immunological differences even in small groups, this study illustrates the promise of the broad and deep information obtained by high-dimensional single cell analyses of human samples to answer toxicological questions regarding health effects of environmental exposures.

Dibutyl phthalate aggravated asthma-like symptoms through oxidative stress and increasing calcitonin gene-related peptide release

Dibutyl phthalate (DBP) is one of the most ubiquitous phthalate esters found in everyday products, and is receiving increased attention as an immunologic adjuvant. However, information regarding DBP-aggravated allergic asthma is still limited. This study used a mouse model sensitized with ovalbumin (OVA) to determine any adverse effects of DBP on allergic asthma. Our results reveal that allergic asthmatic mice exposed to DBP for an extended period had a significant increase in inflammatory cell infiltration; a significant increase in levels of serum immunoglobulin and T helper 2 cell (Th2) and T helper 17 cell (Th17) cytokines in lung tissue; and significant changes in lung histology and AHR, all of which are typical asthmatic symptoms. The levels of oxidative stress and levels of the neuropeptide, calcitonin gene related peptide (CGRP), were also elevated after DBP exposure. Interestingly, blocking oxidative stress by administering melatonin (MT) not only reduced oxidative stress and CGRP levels, but also ameliorated the asthmatic symptoms. Collectively, these results show that DBP exacerbates asthma-like pathologies by increasing the expression of CGRP mediated by oxidative stress.