The role of exposure to phthalates from polyvinyl chloride products in the development of asthma and allergies: a systematic review and meta-analysis

Occurrence and combined exposure of phthalate esters in urban soil, surface dust, atmospheric dustfall, and commercial food in the semi-arid industrial city of Lanzhou, Northwest China

A total of 138 samples including urban soil, surface dust, atmospheric dustfall, and commercial food were collected from the semi-arid industrial city of Lanzhou in Northwest China, and 22 phthalate esters (PAEs) were analyzed in these samples by gas chromatography-mass spectrometry for the pollution characteristics, potential sources, and combined exposure risks of PAEs. The results showed that the total concentration of 22 PAEs (Ʃ22PAEs) presented surface dust (4.94 × 104 ng/g) ≫ dustfall (1.56 × 104 ng/g) ≫ food (2.14 × 103 ng/g) ≫ urban soil (533 ng/g). Di-n-butyl phthalate (DNBP), di-isobutyl phthalate, di(2-ethylhexyl) phthalate (DEHP), and di-isononyl phthalate/di-isodecyl phthalate were predominant in the environmental media and commercial food, being controlled by priority (52.1%-65.5%) and non-priority (62.1%) PAEs, respectively. Elevated Ʃ22PAEs in the urban soil and surface dust was found in the west, middle, and east of Lanzhou. Principal component analysis indicated that PAEs the urban soil and surface dust were related with the emissions of products containing PAEs, atmosphere depositions, and traffic and industrial emissions. PAEs in the foods were associated with the growth and processing environment. The health risk assessment of United States Environmental Protection Agency based on the Chinese population exposure parameters indicated that the total exposure dose of 22 PAEs was from 0.111 to 0.226 mg/kg/day, which were above the reference dose (0.02 mg/kg/day) and tolerable daily intake (TDI, 0.05 mg/kg/day) for DEHP (0.0333-0.0631 mg/kg/day), and TDI (0.01 mg/kg/day) for DNBP (0.0213-0.0405 mg/kg/day), implying that the exposure of PAEs via multi-media should not be ignored; the total non-carcinogenic risk of six priority PAEs was below 1 for the three environmental media (1.21 × 10-5-2.90 × 10-3), while close to 1 for food (4.74 × 10-1-8.76 × 10-1), suggesting a potential non-carcinogenic risk of human exposure to PAEs in food; the total carcinogenic risk of BBP and DEHP was below 1 × 10-6 for the three environmental media (9.13 × 10-10-5.72 × 10-7), while above 1 × 10-4 for DEHP in food (1.02 × 10-4), suggesting a significantly carcinogenic risk of human exposure to DEHP in food. The current research results can provide certain supports for pollution and risk prevention of PAEs.

Microplastics in aquatic ecosystems of Africa: A comprehensive review and meta-analysis

Microplastic pollution is a global issue of great public concern. Africa is flagged to host some of the most polluted water bodies globally, but there is no enough information on the extent of microplastic contamination and the potential risks of microplastic pollution in African aquatic ecosystems. This meta-analysis has integrated data from published articles about microplastic pollution in African aquatic ecosystems. The data on the microplastic distribution and morphological characteristics in water, sediments and biota from African rivers, lakes, oceans and seas were extracted from 75 selected studies. Multivariate statistics were used to critically analyze the effects of sampling and detection methods, ecological risks, spatial distribution and similarity of microplastics in relation to the geographical distance between sampling sites. This study found that sampling methods have significant effect on abundance and morphological characteristics of microplastics and that African aquatic ecosystems are highly contaminated with microplastics compared to global data. The most prevalent colors were white, transparent and black, the most prevalent shapes were fibres and fragments, and the most available polymers were polypropylene (PP), polystyrene (PS) and polyethene terephthalate (PET). Microplastic polymers similarity decreased with an increase in geographical distance between sites. Risk levels of microplastics in African aquatic ecosystems were comparatively high, and more than 40 % of water and sediments showed highest level of ecological risk. This review provides recent information on the prevalence, distribution and risks of microplastics in African aquatic ecosystems.

Pesticides impacts on human health and the environment with their mechanisms of action and possible countermeasures

Pesticides are chemical constituents used to prevent or control pests, including insects, rodents, fungi, weeds, and other unwanted organisms. Despite their advantages in crop production and disease management, the use of pesticides poses significant hazards to the environment and public health. Pesticide elements have now perpetually entered our atmosphere and subsequently contaminated water, food, and soil, leading to health threats ranging from acute to chronic toxicities. Pesticides can cause acute toxicity if a high dose is inhaled, ingested, or comes into contact with the skin or eyes, while prolonged or recurrent exposure to pesticides leads to chronic toxicity. Pesticides produce different types of toxicity, for instance, neurotoxicity, mutagenicity, carcinogenicity, teratogenicity, and endocrine disruption. The toxicity of a pesticide formulation may depend on the specific active ingredient and the presence of synergistic or inert compounds that can enhance or modify its toxicity. Safety concerns are the need of the hour to control contemporary pesticide-induced health hazards. The effectiveness and implementation of the current legislature in providing ample protection for human health and the environment are key concerns. This review explored a comprehensive summary of pesticides regarding their updated impacts on human health and advanced safety concerns with legislation. Implementing regulations, proper training, and education can help mitigate the negative impacts of pesticide use and promote safer and more sustainable agricultural practices.

An integrated in vitro approach to identifying chemically induced oxidative stress and toxicity in mitochondria

Growing concerns exist about increasing chemical usage and the potential health risks. Developing an efficient strategy to evaluate or predict the toxicity of chemicals is necessary. The mitochondria are essential organelles for cell maintenance and survival but also serve as one of the main targets of toxic chemicals. Mitochondria play an important role in the pathology of respiratory disease, and many environmental chemicals may induce impairment of the respiratory system through mitochondrial damage. This study aimed to develop integrated in vitro approaches to identify chemicals that could induce adverse health effects by increasing mitochondria-mediated oxidative stress using the H441 cells, which have a club-cell-like phenotype. Twenty-six environmental toxicants (biocides, phthalates, bisphenols, and particles) were tested, and each parameter was compared with eleven reference compounds. The inhibitory concentrations (IC20 and IC50) and benchmark doses (BMD) of the tested compounds were estimated from three in vitro assays, and the toxic concentration was determined. At the lowest IC20, the effects of compounds on mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) were compared. Principal component analysis and k-mean clustering were performed to cluster the chemicals that had comparable effects on the cells. Chemicals that induce mitochondrial damage at different concentrations were used for an in-depth high-tier assessment and classification as electron transport system (ETS) uncoupling or inhibiting agents. Additionally, using in vitro to in vivo extrapolation (IVIVE) tools, equivalent administration doses and maximum plasma concentrations of tested compounds in human were estimated. This study suggests an in vitro approach to identifying mitochondrial damage by integrating several in vitro toxicity tests and calculation modeling.

A physiologically based pharmacokinetic model of diethyl phthalates in humans

Phthalates are a family of industrial and consumer product chemicals, among which diethyl phthalate (DEP) has been widely used. DEP is metabolized into the active metabolite monoethyl phthalate (MEP) and exposure to DEP may induce male reproductive toxicity, developmental toxicity and hepatotoxicity. To better assess the toxicity of DEP and MEP, it is important to understand and predict their internal concentrations, especially in reproductive organs. Here we present a human physiologically based pharmacokinetic (PBPK) model of DEP. Implemented in R, the PBPK model consists of seven tissue compartments, including blood, gut, liver, fat, skin, gonad, and rest of body (RB). In the blood both DEP and MEP partition into free and bound forms, and tissue distribution is considered as blood flow-limited. DEP is metabolized in the gut and liver into MEP which is further glucuronidated and cleared through the urine. The chemical-specific parameters of the model were predicted in silico or estimated based on published human urinary MEP data after exposure to DEP in the air at 250 or 300 μg/m3 for 3 or 6 h through inhalation and dermal absorption. Sensitivity analysis identified important parameters including partition coefficients of DEP for fat, RB, and skin compartments, and the rate constants for glucuronidation of MEP and urinary excretion, with regard to Cmax, area under the curve (AUC), and clearance half-lives of DEP and MEP. A subset of the sensitive parameters was then included in hierarchical population Bayesian Markov chain Monte Carlo (MCMC) simulations to characterize the uncertainty and variability of these parameters. The model is consistent with the notion that dermal absorption represents a significant route of exposure to DEP in ambient air and clothing can be an effective barrier. The developed human PBPK model can be utilized upon further refinement as a quantitative tool for DEP risk assessment.

Metal-Organic Frameworks for Phthalate Capture

Indoor air contamination by phthalate ester (PAE) derivatives has become a significant concern since traces of PAEs can cause endocrine disruption, among other health issues. PAE abatement from the environment is thus mandatory to further ensure a good quality of indoor air. Herein, we explored the physisorption-based capture of volatile PAEs by metal-organic frameworks (MOFs). A high-throughput computational screening approach was first applied on databases compiling more than 20,000 MOF structures in order to identify the best MOFs for adsorbing traces of dimethyl phthalate (DMP), considered as a representative molecule of the family of PAE contaminants. Among the 20 top candidates, MOF-74(Ni), which combines substantial DMP uptake at the 10 ppm concentration level (∼0.20 g g-1) with high adsorption enthalpy at infinite dilution (-ΔHads(DMP),0 = 109.9 kJ mol-1), was revealed as an excellent porous material to capture airborne DMP. This prediction was validated by further experiments: gravimetric sorption isotherms were carried out on MOF-74(Ni), replacing DMP by dimethyl maleate (DMM), a molecule with a higher vapor pressure and indeed easier to manipulate compared to DMP while mimicking the adsorption behavior of DMP by MOFs, as evidenced by Monte Carlo calculations. Notably, saturation of DMM by MOF-74(Ni) (∼0.35 g g-1 at 343 K) occurs at very low equivalent concentration of the sorbate, i.e., 15 ppm, while half of the DMM molecules remain trapped in the MOF pores, even by heating the system up to 473 K under vacuum. This computational-experimental study reveals for the first time the potential of MOFs for the capture of phthalate ester contaminants as vapors of key importance to address indoor air quality issues.

Maternal di-(2-ethylhexyl) phthalate exposure elicits offspring IFN-λ upregulation: Insights from birth cohort, murine model, and in vitro mechanistic analysis

Maternal exposure to di-(2-ethylhexyl)-phthalate (DEHP), an environmental endocrine disruptor, may lead to developmental immunotoxicity in offspring. The causal relationship and underlying mechanism require further study. A subset of Taiwan Maternal and Infant Cohort Study data (n = 283) was analyzed and found a significant association between urinary DEHP metabolite levels from the third trimester of pregnancy and plasma levels of IL-28A and IL-29, named IFNλs, in cord blood. A trans-maternal murine model mimicking human DEHP exposure way showed that bone marrow-derived dendritic cells from maternal DEHP-exposed F1 offspring secreted higher IL-28A levels than control cells, indicating a potential causal relationship. Human bronchial epithelial cell lines treated with DEHP or its primary metabolite, mono-(2-ethyl-5-hexyl) phthalate (MEHP), expressed significantly higher levels of IFNλs mRNA or protein than controls. MEHP's effect on IFNλs expression was blocked by peroxisome proliferator-activated receptor α (PPARα) and PPARγ antagonists, and inhibited by a histone acetyltransferase inhibitor or a histone methyltransferase inhibitor. Chromatin immunoprecipitation assay showed that MEHP treatment promoted histone modifications at H3 and H4 proteins at the promoter regions of Il28a and Il29 genes. These results suggest maternal DEHP exposure could result in high IFNλ expression in offspring, and the health risk of early-life exposure requires further investigation.

Microplastics in water: types, detection, and removal strategies

Microplastics are one of the most concerning groups of contaminants that pollute most of the surroundings of the Earth. The abundance of plastic materials available in the environment moved the scientific community in defining a new historical era known as Plasticene. Regardless of their minuscule size, microplastics have posed severe threats to the life forms like animals, plants, and other species present in the ecosystem. Ingestion of microplastics could lead to harmful health effects like teratogenic and mutagenic abnormalities. The source of microplastics could be either primary or secondary in which the components of microplastics are directly released into the atmosphere and the breakdown of larger units to generate the smaller molecules. Though numerous physical and chemical techniques are reported for the removal of microplastics, their increased cost prevents the large-scale applicability of the process. Coagulation, flocculation, sedimentation, and ultrafiltration are some of the methods used for the removal of microplastics. Certain species of microalgae are known to remove microplastics by their inherent nature. One of the biological treatment strategies for microplastic removal is the activated sludge strategy that is used for the separation of microplastic. The overall microplastic removal efficiency is significantly high compared to conventional techniques. Thus, the reported biological avenues like the bio-flocculant for microplastic removal are discussed in this review article.

A Study of the Relationship between Phthalate Exposure and the Occurrence of Adult Asthma in Taiwan

Although phthalate esters contribute to airway remodeling by increasing bronchial cells' migration and proliferation, the relationship between human exposure to phthalates and asthma is not understood. We measured phthalate exposure in the human body and evaluated its effect on asthma. Asthma (n = 123) and asthma-free (n = 139) participants were, respectively, recruited from an asthma clinic and the community in Taiwan. The urine levels of six phthalate metabolites were determined by liquid chromatography tandem mass spectrometry. Compared with the controls, male asthma patients had higher means of mono-(2-ethylhexyl) phthalate (MEHP) (116.3 nmol/g), monobutyl phthalate (MBP) (850.3 nmol/g) and monoethyl phthalate (MEP) (965.8 nmol/g), and female patients had greater MBP (2902.4 nmol/g). Each 10-fold increase in the level of these phthalate metabolites was correspondingly associated with a 5.0-, 5.8-, 4.2- and 5.3-fold risk of contracting asthma. Male asthma patients were identified to have a higher proportion of MEHP exposure (32.5%) than the controls (25.3%). In asthma patients, an increase in urine MEHP levels and the total phthalate metabolite concentration were notably linked to increased risks of emergency room visits and being hospitalized. For the occurrence and acute clinical events of adult asthma, phthalate exposures and MEHP retention may contribute to higher risks of contracting this respiratory disorder.

Identifying risk factors for COPD and adult-onset asthma: an umbrella review

BACKGROUND

COPD and adult-onset asthma (AOA) are the most common noncommunicable respiratory diseases. To improve early identification and prevention, an overview of risk factors is needed. We therefore aimed to systematically summarise the nongenetic (exposome) risk factors for AOA and COPD. Additionally, we aimed to compare the risk factors for COPD and AOA.

METHODS

In this umbrella review, we searched PubMed for articles from inception until 1 February 2023 and screened the references of relevant articles. We included systematic reviews and meta-analyses of observational epidemiological studies in humans that assessed a minimum of one lifestyle or environmental risk factor for AOA or COPD.

RESULTS

In total, 75 reviews were included, of which 45 focused on risk factors for COPD, 28 on AOA and two examined both. For asthma, 43 different risk factors were identified while 45 were identified for COPD. For AOA, smoking, a high body mass index (BMI), wood dust exposure and residential chemical exposures, such as formaldehyde exposure or exposure to volatile organic compounds, were amongst the risk factors found. For COPD, smoking, ambient air pollution including nitrogen dioxide, a low BMI, indoor biomass burning, childhood asthma, occupational dust exposure and diet were amongst the risk factors found.

CONCLUSIONS

Many different factors for COPD and asthma have been found, highlighting the differences and similarities. The results of this systematic review can be used to target and identify people at high risk for COPD or AOA.

The disinfectant residues promote the leaching of water contaminants from plastic pipe particles

Disinfection treatment is an indispensable water purification process, but it can leave trace concentrations of disinfectant in the purified water. Disinfectants oxidation can age plastic pipes and release hazardous microplastics and chemicals into drinking water. Lengths of commercially-available unplasticized polyvinyl chloride and polypropylene random copolymer water pipe were ground into particles and exposed to micro-molar concentrations of ClO₂, NaClO, trichloroisocyanuric acid, or O₃ for up to 75 days. The disinfectants aged the plastic and changed its surface morphology and functional groups. Meanwhile, disinfectants could significantly promote the release of organic matter from plastic pipes into the water. ClO₂ generated the highest concentrations of organic matter in the leachates from both plastics. Plasticizers, antioxidants and low molecular weight organic matter were detected in all of the leachates. Leachate samples inhibited the proliferation of CT26 mouse colon cancer and induced oxidative stress in the cells. Even trace concentrations of residual disinfectant can constitute a drinking water risk.

Prenatal phthalate exposure and cord blood DNA methylation

Exposure to phthalates has been shown to impede the human endocrine system, resulting in deleterious effects on pregnant women and their children. Phthalates modify DNA methylation patterns in infant cord blood. We examined the association between prenatal phthalate exposure and DNA methylation patterns in cord blood in a Korean birth cohort. Phthalate levels were measured in 274 maternal urine samples obtained during late pregnancy and 102 neonatal urine samples obtained at birth, and DNA methylation levels were measured in cord blood samples. For each infant in the cohort, associations between CpG methylation and both maternal and neonate phthalate levels were analyzed using linear mixed models. The results were combined with those from a meta-analysis of the levels of phthalates in maternal and neonatal urine samples, which were also analyzed for MEOHP, MEHHP, MnBP, and DEHP. This meta-analysis revealed significant associations between the methylation levels of CpG sites near the CHN2 and CUL3 genes, which were also associated with MEOHP and MnBP in neonatal urine. When the data were stratified by the sex of the infant, MnBP concentration was found to be associated with one CpG site near the OR2A2 and MEGF11 genes in female infants. In contrast, the concentrations of the three maternal phthalates showed no significant association with CpG site methylation. Furthermore, the data identified distinct differentially methylated regions in maternal and neonatal urine samples following exposure to phthalates. The CpGs with methylation levels that were positively associated with phthalate levels (particularly MEOHP and MnBP) were found to be enriched genes and related pathways. These results indicate that prenatal phthalate exposure is significantly associated with DNA methylation at multiple CpG sites. These alterations in DNA methylation may serve as biomarkers of maternal exposure to phthalates in infants and are potential candidates for investigating the mechanisms by which phthalates impact maternal and neonatal health.

Serial fractional exhaled nitric oxide measurements at and off work may help to identify immunologic occupational asthma in cases with complex exposures

Serial measurements of fractional exhaled nitric oxide (FeNO) at home and at work have been described to provide complementary information for the diagnosis of occupational asthma (OA) when specific inhalation challenge (SIC) is missing or doubtful. We describe two cases in which serial FeNO measurements enabled the detection of probable OA after complex exposures. A 25-year-old industrial painter with exposure to a variety of paints suffered from work-related airway symptoms for five years. Lung function was normal, and he was not atopic. SIC with hexamethylene diisocyanate was negative. A 47-year-old sign maker (screen printing, foils) suffering from work-related dyspnoea for seven years. Moderate airway obstruction, but no atopy was detectable. Due to the complex exposures SIC was not performed. Both patients performed FeNO measurements once daily during a 2-week-holiday and a subsequent 2-week-work period. In both cases elevated baseline FeNO decreased to normal (25 ppb) during holidays and increased after resuming work (case 1: 125 ppb, case 2: 45 ppb).

The Relationship Between Potential Occupational Sensitizing Exposures and Asthma: An Overview of Systematic Reviews

OBJECTIVES

The aim was to identify, appraise, and synthesize the scientific evidence of the relationship between potential occupational sensitizing exposures and the development of asthma based on systematic reviews.

METHODS

The study was conducted as an overview of systematic reviews. A systematic literature search was conducted for systematic reviews published up to 9 February 2020. Eligibility study criteria included persons in or above the working age, potential occupational sensitizing exposures, and outcomes defined as asthma. Potential occupational sensitizing exposures were divided into 23 main groups comprising both subgroups and specific exposures. Two reviewers independently selected studies, extracted study data, assessed study quality, and evaluated confidence in study results and level of evidence of the relationship between potential occupational sensitizing exposures and asthma.

RESULTS

Twenty-seven systematic reviews were included covering 1242 studies and 486 potential occupational sensitizing exposures. Overall confidence in study results was rated high in three systematic reviews, moderate in seven reviews, and low in 17 reviews. Strong evidence for the main group of wood dusts and moderate evidence for main groups of mites and fish was found. For subgroups/specific exposures, strong evidence was found for toluene diisocyanates, Aspergillus, Cladosporium, Penicillium, and work tasks involving exposure to laboratory animals, whereas moderate evidence was found for 52 subgroups/specific exposures.

CONCLUSIONS

This overview identified hundreds of potential occupational sensitizing exposures suspected to cause asthma and evaluated the level of evidence for each exposure. Strong evidence was found for wood dust in general and for toluene diisocyanates, Aspergillus, Cladosporium, Penicillium, and work tasks involving exposure to laboratory animals.

Early life exposure to outdoor air pollution and indoor environmental factors on the development of childhood allergy from early symptoms to diseases

BACKGROUND

The prevalence of childhood allergies has increased during past decades leading to serious hospitalization and heavy burden worldwide, yet the key factors responsible for the onset of early symptoms and development of diagnosed diseases are unclear.

OBJECTIVE

To explore the role of early life exposure to ambient air pollution and indoor environmental factors on early allergic symptoms and doctor diagnosed allergic diseases.

METHODS

A retrospective cohort study of 2598 preschool children was conducted at 36 kindergartens in Changsha, China from September of 2011 to February of 2012. A questionnaire was developed to survey each child's early onset of allergic symptoms (wheeze and rhinitis-like symptoms) and doctor diagnosis of allergic diseases (asthma and rhinitis) as well as home environments. Each mother's and child's exposures to ambient air pollutants (PM₁₀, SO₂, and NO₂) and temperature were estimated for in utero and postnatal periods. The associations of early symptoms and diagnosed diseases with outdoor air pollution and indoor environmental variables were examined by logistic regression models.

RESULTS

Childhood early allergic symptoms (33.9%) including wheeze (14.7%) and rhinitis-like symptoms (25.4%) before 2 years old were not associated with outdoor air pollution exposure but was significantly associated with maternal exposure of window condensation at home in pregnancy with ORs (95% CI) of 1.33 (1.11-1.59), 1.30 (1.01-1.67) and 1.27 (1.04-1.55) respectively, and was associated with new furniture during first year after birth with OR (95% CI) of 1.43 (1.02-2.02) for early wheeze. Childhood diagnosed allergic diseases (28.4%) containing asthma (6.7%) and allergic rhinitis (AR) (7.2%) were significantly associated with both outdoor air pollutants (mainly for SO₂ and NO₂) during first 3 years and indoor new furniture, redecoration, and window condensation. We found that sex, age, parental atopy, maternal productive age, environmental tobacco smoke (ETS), antibiotics use, economic stress, early and late introduction of complementary foods, and outdoor air pollution modified the effects of home environmental exposure in early life on early allergic symptoms and diagnosed allergic diseases.

CONCLUSION

Our study indicates that early life exposure to indoor environmental factors plays a key role in early onset of allergic symptoms in children, and further exposure to ambient air pollution and indoor environmental factors contribute to the later development of asthma and allergic rhinitis.

Microbiome alterations associated with phthalate exposures in a US-based sample of Latino workers

Low-wage service sector jobs are largely occupied by racial/ethnic minority workers who often experience an increased risk of elevated chemical exposures, including chemicals like phthalates, compared to the general public. Phthalates have been linked with adverse health effects, including increased risk of atopy and asthma. An important etiological component in respiratory disease, including asthma, is the role of the upper respiratory microbiota in atopic disease development. However, it is unclear how the upper respiratory microbiome is affected by chemical exposures, and how this may impact respiratory outcomes. As Latino workers are often disproportionately exposed to increased concentrations of chemicals and Hispanics have higher rates of adverse respiratory health conditions such as asthma, the aim of this pilot study was to evaluate the effects of 10 unique phthalate urinary biomarkers on the 16S rRNA nasal microbiome. Nasal and urinary samples were collected from 20 facility workers (plumbers, landscapers, electricians) and 20 custodial workers. Our analysis revealed altered microbial composition and diversity according to phthalate urinary biomarker concentration within the two worker groups. Higher urinary biomarker concentrations of select phthalates (MBP, MBIP, and ∑DEHP) were associated with increased Moraxella relative abundance, which has been positively associated with asthma. Within-sample alpha diversity levels were decreased in facility workers and were generally inversely associated with most phthalate urinary biomarker concentrations. Our research suggests that exposure to chemicals in this vulnerable worker group may impact the respiratory microbiome, which may increase risk of development of adverse health conditions. Further research is warranted to refine the mechanistic pathways that underpin the relationships between phthalate exposures and respiratory microbial communities to provide key insights on respiratory pathologies and, most importantly, to identify modifiable risk factors that can be used to direct mitigation efforts aimed at ameliorating the harmful effects of chemical exposures in this understudied occupational population.

The Joint Effect of Perceived Psychosocial Stress and Phthalate Exposure on Hormonal Concentrations during the Early Stage of Pregnancy: A Cross-Sectional Study

Phthalates alter the hormonal balance in humans during pregnancy, potentially affecting embryonic and fetal development. We studied the joint effect of exposure to phthalates, quantified by urinary phthalate metabolite concentration, and perceived psychological stress on the concentration of hormones in pregnant women (n = 90) from the Nitra region, Slovakia, up to the 15th week of pregnancy. We used high-performance liquid chromatography, tandem mass spectrometry (HPLC-MS/MS), and electro-chemiluminescence immunoassay to determine urinary concentrations of phthalates and serum concentrations of hormones, respectively. We used Cohen perceived stress scale (PSS) to evaluate the human perception of stressful situations. Our results showed that mono(carboxy-methyl-heptyl) phthalate (cx-MiNP) and a molar sum of di-iso-nonyl phthalate metabolites (ΣDiNP) were negatively associated with luteinizing hormone (LH) (p ≤ 0.05). Mono(hydroxy-methyl-octyl) phthalate (OH-MiNP) and the molar sum of high-molecular-weight phthalate metabolites (ΣHMWP) were positively associated with estradiol (p ≤ 0.05). PSS score was not significantly associated with hormonal concentrations. When the interaction effects of PSS score and monoethyl phthalate (MEP), cx-MiNP, ΣDiNP, and ΣHMWP on LH were analyzed, the associations were positive (p ≤ 0.05). Our cross-sectional study highlights that joint psychosocial stress and xenobiotic-induced stress caused by phthalates are associated with modulated concentrations of reproductive hormones in pregnant women.

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.

Developmental Exposure to Endocrine Disrupter DDT Interferes with Age-Related Involution of Thymus

The impact of endocrine-disrupting chemicals on the development and involution of the immune system is a possible reason for the increased incidence of disorders associated with inappropriate immune function. The thymus is a lymphoid and also an endocrine organ, and, accordingly, its development and functioning may be impaired by endocrine disruptors. The aim was to evaluate age-related thymus involution in mature rats exposed to the endocrine disruptor DDT during prenatal and postnatal ontogeny. Methodology included in vivo experiment on male Wistar rats exposed to low doses of DDT during prenatal and postnatal development and morphological assessment of thymic involution, including the immunohistochemical detection of proliferating thymocytes. The study was carried out at the early stage of involution. Results: DDT-exposed rats exhibited a normal anatomy, and the relative weight of the thymus was within the control ranges. Histological and immunohistochemical examinations revealed increased cellularity of the cortex and the medulla, higher content of lymphoblasts, and more intensive proliferation rate of thymocytes compared to the control. Evaluation of thymic epithelial cells revealed a higher rate of thymic corpuscles formation. Conclusion: The data obtained indicate that endocrine disrupter DDT disturbs postnatal development of the thymus. Low-dose exposure to DDT during ontogeny does not suppress growth rate but violates the developmental program of the thymus by slowing down the onset of age-related involution and maintaining high cell proliferation rate. It may result in excessive formation of thymus-dependent areas in peripheral lymphoid organs and altered immune response.

Di-(2-ethylhexyl) Phthalate Promotes Allergic Lung Inflammation by Modulating CD8α+ Dendritic Cell Differentiation via Metabolite MEHP-PPARγ Axis

Di-(2-ethylhexyl) phthalate (DEHP), a common plasticizer, is a ubiquitous environmental pollutant that can disrupt endocrine function. Epidemiological studies suggest that chronic exposure to DEHP in the environment is associated with the prevalence of childhood allergic diseases; however, the underlying causal relationship and immunological mechanism remain unclear. This study explored the immunomodulatory effect of DEHP on allergic lung inflammation, while particularly focusing on the impact of DEHP and its metabolite on dendritic cell differentiation and activity of peroxisome proliferator-activated receptor gamma (PPARγ). The results showed that exposure to DEHP at a human tolerable daily intake dose exacerbated allergic lung inflammation in mice. Ex vivo flow cytometric analysis revealed that DEHP-exposed mice displayed a significantly decreased number of CD8α⁺ dendritic cells (DCs) in spleens and DC progenitors in the bone marrow, as well as, less interleukin-12 production in splenic DCs and increased T helper 2 polarization. Pharmacological experiments showed that mono-(2-ethylhexyl) phthalate (MEHP), the main metabolite of DEHP, significantly hampered the differentiation of CD8α⁺ DCs from Fms-like tyrosine kinase 3 ligand-differentiated bone marrow culture, by modulating PPARγ activity. These results suggested that chronic exposure to DEHP at environmentally relevant levels, promotes allergic lung inflammation, at least in part, by altering DC differentiation through the MEHP-PPARγ axis. This study has crucial implications for the interaction(s) between environmental pollutants and innate immunity, with respect to the development of allergic asthma.

Investigation on the Direct Transfer of SVOCs from Source to Settled Dust: Analytical Model and Key Parameter Determination

Settled dust is an important medium for semivolatile organic compound (SVOC) transport indoors. Understanding the mechanism of interaction between SVOCs and settled dust can greatly improve the exposure assessment. This study develops an analytical model to elucidate the mechanism of direct contact between SVOC sources and settled dust. The model incorporates the adsorption of SVOCs onto indoor surfaces, which was ignored in previous numerical models. Based on this model, a hybrid optimization method is applied to determine the key parameters of SVOC transport, i.e., the diffusion coefficient in the dust, the dust-air partition coefficient, and the chamber surface-air partition coefficient. Experiments of direct contact between SVOC source materials containing organophosphorus flame retardants (OPFRs) and settled dust were conducted in chambers. The key parameters were determined by performing curve fitting using data collected from the OPFR chamber tests and from the literature on phthalates. The reliability and robustness of the model and measurement method are demonstrated by the high fitting accuracy and sensitivity analysis. The obtained key parameters are more accurate than those from correlations in prior studies. Further analysis indicates that dust-air partition coefficient plays an important role and the adsorption effect on surfaces cannot be neglected for SVOC transport.

DEHP induces ferroptosis in testes via p38α-lipid ROS circulation and destroys the BTB integrity

Exposure to Di (2-ethylhexyl) phthalate (DEHP) has been associated with toxic effects of the reproductive system. However, the exact mechanism remains to be elucidated. In this study we explored the testicular toxicity induced by DEHP, and the probable molecular mechanism in the process. In vivo, the results demonstrated that DEHP affected testosterone levels and blood-testosterone barrier (BTB) integrity and caused ferroptosis. We further demonstrated that DEHP up-regulated the expression of p38α, p-p38α, p53, p-p53, SAT1, ALOX15. This view has also been confirmed in TM4 cells. After pre-treatment with fer-1 or si-MAPK14, the expression of either p53, p-p53, SAT1 and ALOX15 up-regulated by MEHP was inhibited in vitro. Interestingly, p38α can prevent the accumulation of lipid ROS, and the production of lipid ROS in turn promoted the expression of p38α, thus forming a feedback loop during the ferroptosis. In this process, a vicious cycle consisting of p38α, p53, SAT1, ALOX15, lipid ROS was involved. This study provides new mechanistic insights into DEHP-induced toxicity of the reproductive system.

Dibutyl phthalate exposure alters T-cell subsets in blood from allergen-sensitized volunteers

Phthalates are ubiquitous environmental contaminants associated with allergic disease in epidemiological and animal studies. This investigation aims to support these associations by interrogating systemic immune effects in allergen-sensitized volunteers after controlled indoor air exposure to a known concentration of dibutyl phthalate (DBP). The phthalate-allergen immune response (PAIR) study enrolled 16 allergen-sensitized participants to a double-blinded, randomized, crossover exposure to two conditions (DBP or control air for 3 hr), each followed immediately by inhaled allergen challenge. Peripheral blood immune cell composition and activation along with inflammatory mediators were measured before and after exposure. DBP exposure prior to the inhaled allergen challenge increased the percentage of CD4⁺ T helper cells and decreased the percentage of regulatory T cells (3 hr and 20 hr post-exposure), while only modest overall effects were observed for inflammatory mediators. The cells and mediators affected by the phthalate exposure were generally not overlapping with the endpoints affected by allergen inhalation alone. Thus, in distinction to our previously published effects on lung function, DBP appears to alter endpoints in peripheral blood that are not necessarily enhanced by allergen alone. Further studies are needed to clarify the role of phthalate-induced systemic effects in disease pathogenesis.

Indoor exposure to phthalates and polycyclic aromatic hydrocarbons (PAHs) to Canadian children: the Kingston allergy birth cohort

BACKGROUND

Canadian children are widely exposed to phthalates and polycyclic aromatic hydrocarbons (PAHs) from indoor sources. Both sets of compounds have been implicated in allergic symptoms in children.

OBJECTIVE

We characterize concentrations of eight phthalates and 12 PAHs in floor dust from the bedrooms of 79 children enrolled in the Kingston Allergy Birth Cohort (KABC).

METHOD

Floor dust was collected from the bedrooms of 79 children who underwent skin prick testing for common allergens after their first birthday. Data were collected on activities, household, and building characteristics via questionnaire.

RESULTS

Diisononyl phthalate (DiNP) and phenanthrene were the dominant phthalate and PAH with median concentrations of 561 µg/g and 341 ng/g, respectively. Benzyl butyl phthalate (BzBP) and chrysene had the highest variations among all tested homes, ranging from 1-95% to 1-99%, respectively.

SIGNIFICANCE

Some phthalates were significantly associated with product and material use such as diethyl phthalate (DEP) with fragranced products and DiNP and DiDP with vinyl materials. Some PAHs were significantly associated with household characteristics, such as benzo[a]pyrene with smoking, and phenanthrene and fluoranthene with the presence of an attached garage. Socioeconomic status (SES) had positive and negative relationships with some concentrations and some explanatory factors. No significant increases in risk of atopy (positive skin prick test) was found as a function of phthalate or PAH dust concentrations.

Toxicology and carcinogenesis studies of di(2-ethylhexyl) phthalate administered in feed to Sprague Dawley (Hsd:Sprague Dawley SD) rats

Di(2-ethylhexyl) phthalate (DEHP) is a member of the phthalate ester chemical class that occurs commonly in the environment and to which humans are widely exposed. Lifetime exposure to DEHP is likely to occur, including during the in utero and early postnatal windows of development. To date, no carcinogenicity assessments of DEHP have used a lifetime exposure paradigm that includes the perinatal period (gestation and lactation). The National Toxicology Program (NTP) tested the hypothesis that exposure during the perinatal period would alter the DEHP carcinogenic response quantitatively (more neoplasms) or qualitatively (different neoplasm types). Two chronic carcinogenicity assessments of DEHP were conducted in which Sprague Dawley (Hsd:Sprague Dawley SD) rats were exposed to dosed feed containing 0, 300, 1,000, 3,000, or 10,000 ppm DEHP for 2 years using different exposure paradigms. In Study 1, groups of 45 F0 time-mated females were provided dosed feed beginning on gestation day (GD) 6 through lactation. On postnatal day (PND) 21, groups of 50 F1 rats per sex continued on the study and were provided dosed feed containing the same DEHP concentration as their respective dam for 2 years. In Study 2, groups of 50 rats per sex, aged 6 to 7 weeks at study start, were provided dosed feed containing DEHP for 2 years. (Abstract Abridged).

Urinary phthalate metabolites among workers in plastic greenhouses in western China

Agricultural plastic greenhouse (PG) production can extend the growing season of crops to satisfy domestic consumption in countries such as China. Workers in PGs have potential higher phthalate exposure risks than the general population as phthalate accumulation has been observed in greenhouse soil, air, and crops. To date, biomonitoring tests of phthalates for the working population have not been carried out. To address this shortage, we conducted a pilot study in Shaanxi Province, China, among 35 healthy PG workers by follow-up recording their seasonal dietary habits and work activities and urine sample collection and measurement between 2018 and 2019. The objectives were to uncover the association between phthalate metabolites and the population characteristics, seasonal and diurnal variations and causes, and to estimate exposure risks and contributions of exposure pathways from PG production systems. A total of 13 phthalate metabolite concentrations (Σ₁₃ phthalate metabolites) ranged from 102 to 781 (5th-95th) ng/mL (median: 300 ng/mL). Mono-n-butyl phthalate (MNBP) made up 51.3% of Σ₁₃ phthalate metabolites, followed by the sum of four di-2-ethylhexyl phthalate (DEHP) metabolites (24.2%), mono-2-isobutyl phthalate (MIBP) (13.4%), and mono-ethyl phthalate (MEP) (9.8%). The concentrations of MNBP and MIBP in summer were significantly higher than the levels in winter (p < 0.0001). A total of 62.3% of the PG worker population was shown to have exposure risks, and the proportion was as high as 79.4% in summer. Phthalate exposure of the workers from PG production systems constituted over 20% of the total creatinine-based daily intake, and consuming vegetables and fruit planted in PGs and inhalation in PGs were the two largest exposure pathways. Our findings demonstrate that it is important to protect workers in PGs from phthalate exposure risks, and phasing out the use of plastic materials containing phthalates in PGs is imperative, to guarantee food safety in PGs.

ASIA (Shoenfeld's syndrome) due to hysteroscopic Essure sterilization

Essure (TM, Bayer; Leverkusen, Germany) may act as a potential cause of autoimmune/inflammatory syndrome by adjuvants (ASIA). Essure is a device hysteroscopically inserted into the fallopian tubes to elicit a local inflammatory response for permanent sterilization. Patients with ASIA present with a constellation of symptoms including fatigue, cognitive impairment, and arthralgias. It is well known that ASIA is triggered by implantation of foreign material such as breast implants and mesh for hernia repair. In the current study, we present a retrospective cohort of 33 patients electing to remove Essure due to pelvic pain and systemic symptoms consistent with an ASIA diagnosis, and detail a case report of an Essure patient. Furthermore, we reviewed the existing literature on adverse events associated with Essure and studies assessing outcomes following explantation. The concept that Essure may trigger ASIA is further supported by both in vivo and in vitro studies demonstrating immunostimulatory effects of the material components of the device. We conclude that the existing evidence is sufficient to recommend screening of Essure recipients for ASIA symptoms, and where indicated, discussion of the risks and potential benefits of surgical removal.

An integrated exposure and pharmacokinetic modeling framework for assessing population-scale risks of phthalates and their substitutes

To effectively incorporate in vitro-in silico-based methods into the regulation of consumer product safety, a quantitative connection between product phthalate concentrations and in vitro bioactivity data must be established for the general population. We developed, evaluated, and demonstrated a modeling framework that integrates exposure and pharmacokinetic models to convert product phthalate concentrations into population-scale risks for phthalates and their substitutes. A probabilistic exposure model was developed to generate the distribution of multi-route exposures based on product phthalate concentrations, chemical properties, and human activities. Pharmacokinetic models were developed to simulate population toxicokinetics using Bayesian analysis via the Markov chain Monte Carlo method. Both exposure and pharmacokinetic models demonstrated good predictive capability when compared with worldwide studies. The distributions of exposures and pharmacokinetics were integrated to predict the population distributions of internal dosimetry. The predicted distributions showed reasonable agreement with the U.S. biomonitoring surveys of urinary metabolites. The "source-to-outcome" local sensitivity analysis revealed that food contact materials had the greatest impact on body burden for di(2-ethylhexyl) adipate (DEHA), di-2-ethylhexyl phthalate (DEHP), di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), and di(2-propylheptyl) phthalate (DPHP), whereas the body burden of diethyl phthalate (DEP) was most sensitive to the concentration in personal care products. The upper bounds of predicted plasma concentrations showed no overlap with ToxCast in vitro bioactivity values. Compared with the in vitro-to-in vivo extrapolation (IVIVE) approach, the integrated modeling framework has significant advantages in mapping product phthalate concentrations to multi-route risks, and thus is of great significance for regulatory use with a relatively low input requirement. Further integration with new approach methodologies will facilitate these in vitro-in silico-based risk assessments for a broad range of products containing an equally broad range of chemicals.

Association of phthalate exposure and airway dysfunction with mediation by serum periostin

BACKGROUND

Phthalates can cause respiratory and immunological disorders. However, little is known about the role of serum periostin and YKL-40 levels in mediating the effects of phthalates. We investigated the mediating role of these biomarkers in the relationship between phthalates and airway dysfunction.

METHODS

A total of 487 children (aged 10-12 years old) were examined. Four high-molecular-weight phthalate (HMWP) [Σ₄ HMWP] metabolites and 3 low-molecular-weight phthalate (LMWP) [Σ₃ LMWP] metabolites in urine samples were measured. Serum periostin and YKL-40 levels were measured. Airway function was measured using impulse oscillometry. A mediation model was used to quantify the mediating effects of periostin and YKL-40 on airway dysfunction.

RESULTS

After adjustment for height, gender, BMI z-score, aeroallergen sensitization, secondary smoking, and vitamin D level, the level of urinary Σ₃ LMWP metabolites was significantly associated with respiratory system resistance at 5 Hz (Rrs5; adjusted β: 0.020, 95% CI: 0.005-0.034; p = .010). The levels of urinary Σ₄ HMWP and Σ₃ LMWP metabolites were significantly associated with periostin level, but not with YKL-40 level. In addition, the periostin level was associated with Rrs5 (adjusted β: 0.048, 95% CI: 0.015-0.081; p = .005) and Rrs20-5 (adjusted β: 0.040, 95% CI: 0.011-0.069; p = .007). Serum periostin level had a significant effect in mediating the relationship between Σ₃ LMWP and Rrs5 (13.9%, 95% CI: 10.7-77.0; p < .001).

CONCLUSION

Exposure to LMWPs was significantly associated with airway dysfunction, and this effect was partially attributable to increased serum periostin level.

Indoor PM2.5, VOCs and asthma outcomes: A systematic review in adults and their home environments

INTRODUCTION

As the amount of time people spend indoors increases globally, exposure to indoor air pollutants has become an important public health concern. Asthma is a complex disease caused and/or exacerbated by increased exposure to diverse chemical, physical and biological exposures from multiple indoor and outdoor sources. This review aims to investigate the relationship between increased indoor PM and VOC concentrations (i.e. objectively measured) and the risk of adult asthma in higher-income countries.

METHODS

Eleven databases were systematically searched on the February 1, 2019 and again on the February 2, 2020. Articles were limited to those published since 1990. Reference lists were independently screened by three reviewers and authors were contacted to identify relevant articles. Backwards and forward citation chasing was used to identify further studies. Data were extracted from included studies meeting our eligibility criteria by three reviewers and assessed for quality using the Newcastle-Ottawa scale designed for case-control and cohort studies.

RESULTS

Twelve studies were included in a narrative synthesis. We found insufficient evidence to determine the effect of PM2.5 on asthma in the indoor home environment. However, there was strong evidence to suggest that VOCs, especially aromatic compounds, and aliphatic compounds, were associated with increased asthma symptoms.

DISCUSSION & CONCLUSION

Although no single exposure appears to be responsible for the development of asthma or its associated symptoms, the use of everyday products may be associated with increased asthma symptoms. To prevent poor health outcomes among the general population, health professionals and industry must make a concerted effort to better inform the general population of the importance of appropriate use of and storage of chemicals within the home as well as better health messaging on product labelling.

The aggravation of allergic airway inflammation with dibutyl phthalate involved in Nrf2-mediated activation of the mast cells

Dibutyl phthalate (DBP)-an organic pollutant-is ubiquitous in the environment. DBP as an immune adjuvant is related to the development of multiple allergic diseases. However, the current research involving DBP-induced pulmonary toxicity remains poorly understood. Therefore, this research aimed to explore the adverse effect and potential mechanism of DBP exposure on the lungs in rats. In our study, ovalbumin was used to build a rat model of allergic airway inflammation to study any harmful effect of DBP exposure on lung tissues. Rats were treated by intragastric administration of DBP (500 mg kg^-1 or 750 mg kg^-1) and/or subcutaneous injection of SFN (4 mg kg^-1). The results of histopathological analysis, cell count, and myeloperoxidase showed that DBP promoted the inflammatory damage of lungs. In the lung tissues, the detection of terminal deoxynucleotidyl transferase dUNT nick end labeling and oxidative stress indices showed that DBP significantly increased the level of apoptosis and oxidative stress. Western blot analysis indicated that DBP raised the expression level of thymic stromal lymphopoietin and reduced the nuclear expression level of nuclear factor-erythroid-2-related factor 2 (Nrf2), which was further verified by quantitative real-time PCR. Meanwhile, DBP treatment markedly up-regulated the inflammatory cytokines such as IL-4 and IL-13, and rat mast cell protease-2, a marker secreted by mast cells (MCs). Conversely, sulforaphane, a Nrf2 inducer, ameliorated the pulmonary damage induced by DBP in the above. Altogether, our data provides a new insight into the impacts of the activation of MCs on the DBP-induced pulmonary toxicity as well as the safety evaluation of DBP.

Agricultural Plastic Pollution in China: Generation of Plastic Debris and Emission of Phthalic Acid Esters from Agricultural Films

Agricultural plastic films have been proven highly advantageous, but they also cause pollution of plastic debris and associated chemicals. Phthalates (phthalic acid esters, PAEs), an important additive of agricultural films, can be released and contaminate the environment. Here, we analyzed the agricultural plastic usage and assessed plastic debris in China and developed a method to estimate PAE emissions from agricultural films. Additionally, the environmental fate of PAEs was evaluated using a fugacity-based multimedia model. The agricultural plastic film usage in China in 2017 was 2,528,600 tons. After agricultural film recycling and water erosion, the plastic debris amount was estimated as 465,016 tons. The water erosion process carried 4329 tons of plastic debris into the aquatic environment. During its lifetime, the agricultural film released a total of 91.5 tons of two typical types of PAEs. PAEs from the mulching film would mostly be removed through degradation, while those from the greenhouse film accumulate in vegetables. Populated regions exhibited more serious PAE pollution in vegetables but with no immediate health risks. The model was well evaluated using comparable measured concentrations and uncertainty analysis based on the Monte Carlo method. The findings from this study demonstrate the serious agricultural plastic pollution problem and associated PAE contamination in China.

[Pediatric exposure to endocrine disruptors and carcinogenic, mutagenic or reprotoxic substances by pharmaceutical forms intended for the cutaneous route: Regulatory provisions in France, in Europe, and state of the art of scientific knowledge]

OBJECTIVES

The objective is to conduct a review of pediatric exposure to substances whose endocrine disrupting (ED), carcinogenic, mutagenic, or reprotoxic (CMR) character has been confirmed or remains controversial, through their use in pharmaceutical forms intended for the cutaneous route, as well as regulatory measures diligent at the national and European levels.

METHODS

A bibliographical search was carried out on the databases PubMed, Web of Science, Cochrane Library, supplemented by a search for recommendations from French and European authorities. References were selected following an assessment of their relevance to our topic.

RESULTS

Seventy-one references were selected. Pediatric exposure to endocrine disruptors and CMR substances remains through products formulated for their use, but also through indirect exposure to products commonly used by adults. Exposure arises both from the choice of excipients (parabens, phenoxyethanol), packaging materials (bisphenols, phthalates) and the qualitative or quantitative nature of the active ingredients (iodine, boron, pyrethroids, organic sunscreens).

CONCLUSION

The health professional must be able to develop a critical mind on such substances in order to inform and promote therapeutic adherence, guaranteeing the safety of the child's care.

Effect of prenatal exposure to phthalates on epigenome-wide DNA methylations in cord blood and implications for fetal growth: The Hokkaido Study on Environment and Children's Health

Prenatal exposure to phthalates negatively affects the offspring's health. In particular, epigenetic alterations, such as DNA methylation, may connect phthalate exposure with health outcomes. Here, we evaluated the association of di-2-ethylhexyl phthalate (DEHP) exposure in utero with cord blood epigenome-wide DNA methylation in 203 mother-child pairs enrolled in the Hokkaido Study on Environment and Children's Health, using the Illumina HumanMethylation450 BeadChip. Epigenome-wide association analysis demonstrated the predominant positive associations between the levels of the primary metabolite of DEHP, mono(2-ethylhexyl) phthalate (MEHP), in maternal blood and DNA methylation levels in cord blood. The genes annotated to the CpGs positively associated with MEHP levels were enriched for pathways related to metabolism, the endocrine system, and signal transduction. Among them, methylation levels of CpGs involved in metabolism were inversely associated with the offspring's ponderal index (PI). Further, clustering and mediation analyses suggested that multiple increased methylation changes may jointly mediate the association of DEHP exposure in utero with the offspring's PI at birth. Although further studies are required to assess the impact of these changes, this study suggests that differential DNA methylation may link phthalate exposure in utero to fetal growth and further imply that DNA methylation has predictive value for the offspring's obesity.

Endocrine-Disrupting Chemicals and Infectious Diseases: From Endocrine Disruption to Immunosuppression

Endocrine-disrupting chemicals (EDCs) are hormonally active compounds in the environment that interfere with the body's endocrine system and consequently produce adverse health effects. Despite persistent public health concerns, EDCs remain important components of common consumer products, thus representing ubiquitous contaminants to humans. While scientific evidence confirmed their contribution to the severity of Influenza A virus (H1N1) in the animal model, their roles in susceptibility and clinical outcome of the coronavirus disease (COVID-19) cannot be underestimated. Since its emergence in late 2019, clinical reports on COVID-19 have confirmed that severe disease and death occur in persons aged ≥65 years and those with underlying comorbidities. Major comorbidities of COVID-19 include diabetes, obesity, cardiovascular disease, hypertension, cancer, and kidney and liver diseases. Meanwhile, long-term exposure to EDCs contributes significantly to the onset and progression of these comorbid diseases. Besides, EDCs play vital roles in the disruption of the body's immune system. Here, we review the recent literature on the roles of EDCs in comorbidities contributing to COVID-19 mortality, impacts of EDCs on the immune system, and recent articles linking EDCs to COVID-19 risks. We also recommend methodologies that could be adopted to comprehensively study the role of EDCs in COVID-19 risk.

The Effect of Residential Environment on Respiratory Diseases and Pulmonary Function in Children from a Community in Jilin Province of China

Purpose

Respiratory disease is a major and increasingly global epidemic that has a great impact on humans, especially children. The purpose of this study was to identify environmental risk factors for respiratory diseases and pulmonary function in children.

Patients and Methods

A population-based, cross-sectional survey of respiratory diseases and environmental risk factors was conducted in Jilin Province, China. Complete questionnaire information was available for 2419 children, while adequate pulmonary function data were available for a subgroup of 627 children.

Results

Our study found that environmental risk factors for respiratory health in children were mainly concentrated indoors. After adjusting for demographic factors, insecticide exposure and passive smoking were risk factors for respiratory disease and industrial pollutant sources, insecticide exposure and the use of a fume exhauster may be independent risk factors for recurrent respiratory infections. The main fuel for cooking in the winter and passive smoking were the main influencing factors of pulmonary function indicators.

Conclusion

The primary risk factors differ in different respiratory diseases. Passive smoking remains a critical adverse factor for respiratory illness and pulmonary function in children, and it is important to reduce children’s exposure to passive smoking to increase pulmonary health. Insecticide exposure may be a neglected environmental risk factor, and further investigations are still needed to explore the relationship and mechanisms between insecticide exposure and children’s respiratory health.

Associations of dermal diethyl phthalate level with changes in lung function test value mediated by absolute eosinophil count: A panel study of adults in southern Taiwan

Phthalate concentrations in indoor and outdoor dust are associated with respiratory disease. Both immunoglobulin E (IgE) and eosinophil count are associated with airway inflammation from exposure to environmental allergens. Dermal phthalate level can be used as a matrix for assessing personal exposure through direct absorption from the air, particle deposition, or contact with contaminated products. However, the association between dermal phthalate level and changes in lung function test values, as mediated by immunological response, remains unclear. In total, 237 adults in southern Taiwan were recruited. Spirometry measurements (in L) of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were taken on visits 1 (2016-2018) and 2 (2019). Dermal phthalate level, absolute eosinophil count, and IgE level were recorded on visit 1. Mean changes in FVC and FEV1 decrease pear year, as determined through pairwise comparisons, were significant (^diffFVC_{per year}: -0.46, 95% CI: -0.51, -0.41; p < 0.001; ^diffFEV1_{per year}: -0.37, 95% confidence interval [CI]: -0.41, -0.34; p < 0.001). For FEV1 decrease, log-unit increases in dermal diethyl phthalate (DEP) were positively associated with ^diffFEV1_{per year} (β = 0.096; 95% CI: 0.042, 0.150; p = 0.001) and negatively associated with absolute eosinophil count (β= -0.201; 95% CI: -0.380, -0.023; p= 0.027). Log-unit increases in absolute eosinophil count were negatively associated with ^diffFEV1_{per year} (β= -0.109; 95% CI: -0.150, -0.068; p < 0.001). Absolute eosinophil count mediated 19.70% of the association between dermal DEP level and ^diffFEV1_{per year}. For FVC decrease, log-unit increases in dermal DEP were positively associated with ^diffFVC_{per year} (β = 0.095; 95% CI: 0.035, 0.155; p = 0.002) and negatively associated with absolute eosinophil count (β = -0.243; 95% CI: -0.427, -0.060; p = 0.010). Log-unit increases in absolute eosinophil count were negatively associated with ^diffFVC_{per year} (β= -0.122; 95% CI: -0.168, -0.076; p < 0.001). Absolute eosinophil count mediated 29.98% of the association between dermal DEP level and ^diffFVC_{per year}. The results suggest that dermal DEP level is positively associated with changes in lung function test values and is mediated by absolute eosinophil count.

Association between Phthalate Exposure and Frailty among Community-Dwelling Older Adults: A Repeated Panel Data Study

Only a few studies have examined the impacts of environmental exposure on frailty. This study investigated the association between phthalates and frailty among community-dwelling older adults. The Korean Elderly Environmental Panel II (KEEP II) study is a repeated panel data study of 800 community-dwelling older adults in South Korea. Frailty was measured with five items defined by Fried and colleagues. Environmental pollutants in the form of two types of metabolites for Di-ethylhexyl phthalate (DEHPs)-Mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and Mono (2-ethyl-5-oxohexyl) phthalate (MEOHP)-were obtained from urine specimens. Analyses were performed using repeated linear mixed models. The concentration levels of both MEOHP and MEHHP in urine were significantly higher in the pre-frail or frail group than its counterparts. While adjusting for covariates, MEOHP level was positively associated with the likelihood of being pre-frail or frail in both males and females; the concentration level of MEHHP also had a positive impact on the likelihood of being pre-frail or frail in females. The DEHP metabolite concentrations were significantly lower among adults with daily fruit consumption in both males and females. DEHPs, measured by metabolite concentrations, may increase the risk of frailty among older men and women; further studies are necessary. The preventive effects of nutrition on DEHP risk should also be further investigated.

Scoping Review-The Association between Asthma and Environmental Chemicals

Asthma is one of the most common chronic diseases worldwide affecting all age groups from children to the elderly. In addition to other factors such as smoking, air pollution and atopy, some environmental chemicals are shown or suspected to increase the risk of asthma, exacerbate asthma symptoms and cause other respiratory symptoms. In this scoping review, we report environmental chemicals, prioritized for investigation in the European Human Biomonitoring Initiative (HBM4EU), which are associated or possibly associated with asthma. The substance groups considered to cause asthma through specific sensitization include: diisocyanates, hexavalent chromium Cr(VI) and possibly p-phenylenediamine (p-PDA). In epidemiological studies, polyaromatic hydrocarbons (PAHs) and organophosphate insecticides are associated with asthma, and phthalates, per- and polyfluoroalkyl substances (PFASs), pyrethroid insecticides, mercury, cadmium, arsenic and lead are only potentially associated with asthma. As a conclusion, exposure to PAHs and some pesticides are associated with increased risk of asthma. Diisocyanates and Cr(VI) cause asthma with specific sensitization. For many environmental chemicals, current studies have provided contradicting results in relation to increased risk of asthma. Therefore, more research about exposure to environmental chemicals and risk of asthma is needed.

Direct Transfer of Phthalate and Alternative Plasticizers from Indoor Source Products to Dust: Laboratory Measurements and Predictive Modeling

Phthalate and alternative plasticizers are semivolatile organic compounds (SVOCs) and among the most abundant indoor pollutants. Although ingestion of dust is one of the major exposure pathways to them, migration knowledge from source products to indoor dust is still limited. Systematic chamber measurements were conducted to investigate the direct transfer of these SVOCs between source products and dust in contact with the source. Substantial direct source-to-dust transfer of SVOCs was observed for all tests. The concentration of bis(2-ethylhexyl)phthalate in dust was 12 times higher than the pre-experimental level after only two days of source-dust contact. A mechanistic model was developed to predict the direct transfer process, and a reasonable agreement between model predictions and measurements was achieved. The octanol/air partition coefficient (K_oa) of SVOCs, the emission parameter of the source product (y₀), and the characteristics of the dust layer (i.e., porosity and thickness) control the transfer, affecting the SVOC concentration in dust, the kinetics of direct transfer, or both. Dust mass loading has a significant influence on the transfer, while relative humidity only has a limited effect. The findings suggest that minimizing the use of SVOC-containing products and house vacuuming are effective intervention strategies to reduce young children's exposure to SVOCs.

Exposure to Polyhexamethylene Guanidine Exacerbates Bronchial Hyperresponsiveness and Lung Inflammation in a Mouse Model of Ovalbumin-Induced Asthma

Humidifier disinfectants (HDs) exposure has now been associated with acute lung injury and pulmonary fibrosis; polyhexamethylene guanidine (PHMG) has been confirmed to cause severe lung inflammation and fibrosis in mice. Recent evidence also indicates that HDs exposure increases the asthma risk in children, but the underlying mechanisms remain unclear. We aimed to investigate the effects of PHMG exposure on asthma in mice and the potential underlying mechanisms. BALB/c mice were intranasally administered PHMG (0.1 mg/kg/day; 5 days per week) during 2 episodes of ovalbumin (OVA) sensitization and were then challenged with 1% OVA by inhalation. Bronchial hyperresponsiveness (BHR), inflammatory cell influx into bronchoalveolar lavage (BAL) fluid, serum total and OVA-specific immunoglobulin (Ig) E levels, and histopathological changes in the lung were analyzed. The levels of asthma-related cytokines and chemokines were assayed in the lung tissues to evaluate possible mechanisms. Exposure to PHMG following OVA sensitization and challenge significantly enhanced BHR, inflammatory cell counts in BAL fluid, airway inflammation, and total serum IgE levels in the asthma mouse model. In addition, the levels of chemokine ligand (CCL) 11 and serpine F1/pigment epithelium-derived factor (SERPINF1) were significantly elevated in the lungs of these mice compared to those in the control and OVA-treated only groups. Our findings suggest that PHMG can enhance the development of allergic responses and lung inflammation via CCL11- and SERPINF1-induced signaling in a mouse model of asthma.

Dibutyl Phthalate Augments Allergen-induced Lung Function Decline and Alters Human Airway Immunology. A Randomized Crossover Study

Rationale: Phthalates are a group of chemicals used in common commercial products. Epidemiological studies suggest that phthalate exposure is associated with development or worsening of allergic diseases such as asthma. However, effects of dibutyl phthalate (DBP) or other phthalates found in high concentrations in indoor air have never been examined in allergic individuals in a controlled exposure setting.Objectives: To investigate the airway effects in humans caused by inhalation of a known concentration of a single phthalate, DBP.Methods: In a randomized crossover study, 16 allergen-sensitized participants were exposed to control air or DBP for 3 hours in an environmental chamber followed immediately by an allergen inhalation challenge. Bronchoalveolar wash and lavage were obtained 24 hours after exposure. Lung function, early allergic response, airway responsiveness, inflammation, immune mediators, and immune cell phenotypes were assessed after DBP exposure.Measurements and Main Results: DBP exposure increased the early allergic response (21.4% decline in FEV₁ area under the curve, P = 0.03). Airway responsiveness was increased by 48.1% after DBP exposure in participants without baseline hyperresponsiveness (P = 0.01). DBP increased the recruitment of BAL total macrophages by 4.6% (P = 0.07), whereas the M2 macrophage phenotype increased by 46.9% (P = 0.04). Airway immune mediator levels were modestly affected by DBP.Conclusions: DBP exposure augmented allergen-induced lung function decline, particularly in those without baseline hyperresponsiveness, and exhibited immunomodulatory effects in the airways of allergic individuals. This is the first controlled human exposure study providing biological evidence for phthalate-induced effects in the airways.Clinical trial registered with www.clinicaltrials.gov (NCT02688478).

A combined cohort analysis of prenatal exposure to phthalate mixtures and childhood asthma

BACKGROUND

Previous studies of prenatal phthalate exposure and childhood asthma are inconsistent. These studies typically model phthalates as individual, rather than co-occurring, exposures. We investigated whether prenatal phthalates are associated with childhood wheeze and asthma using a mixtures approach.

METHODS

We studied dyads from two prenatal cohorts in the ECHO-PATHWAYS consortium: CANDLE, recruited 2006-2011 and TIDES, recruited 2011-2013. Parents reported child respiratory outcomes at age 4-6 years: ever asthma, current wheeze (symptoms in past 12 months) and current asthma (two affirmative responses from ever asthma, recent asthma-specific medication use, and/or current wheeze). We quantified 11 phthalate metabolites in third trimester urine and estimated associations with child respiratory outcomes using weighted quantile sum (WQS) logistic regression, using separate models to estimate protective and adverse associations, adjusting for covariates. We examined effect modification by child sex and maternal asthma.

RESULTS

Of 1481 women, most identified as White (46.6%) or Black (44.6%); 17% reported an asthma history. Prevalence of ever asthma, current wheeze and current asthma in children was 12.3%, 15.8% and 12.3%, respectively. Overall, there was no adverse association with respiratory outcomes. In sex-stratified analyses, boys' phthalate index was adversely associated with all outcomes (e.g., boys' ever asthma: adjusted odds ratio per one quintile increase in WQS phthalate index (AOR): 1.42; 95% confidence interval (CI): 1.08, 1.85, with mono-ethyl phthalate (MEP) weighted highest). Adverse associations were also observed in dyads without maternal asthma history, driven by MEP and mono-butyl phthalate (MBP), but not in those with maternal asthma history. We observed protective associations between the phthalate index and respiratory outcomes in analysis of all participants (e.g., ever asthma: AOR; 95% CI: 0.81; 0.68, 0.96), with di(2-ethylhexyl)phthalate (DEHP) metabolites weighted highest.

CONCLUSIONS

Results suggest effect modification by child sex and maternal asthma in associations between prenatal phthalate mixtures and child asthma and wheeze.

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

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

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.

Phthalate exposure and allergic diseases: Review of epidemiological and experimental evidence

Phthalates are among the most ubiquitous environmental contaminants and endocrine-disrupting chemicals. Exposure to phthalates and related health effects have been extensively studied over the past four decades. An association between phthalate exposure and allergic diseases has been suggested, although the literature is far from conclusive. This article reviews and evaluates epidemiological (n = 43), animal (n = 49), and cell culture studies (n = 42), published until the end of 2019, on phthalates and allergic diseases, such as asthma, rhinoconjunctivitis, and eczema. In contrast to earlier reviews, emphasis is placed on experimental studies that use concentrations with relevance for human exposure. Epidemiological studies provide support for associations between phthalate exposures and airway, nasal, ocular, and dermal allergic disease outcomes, although the reported significant associations tend to be weak and demonstrate inconsistencies for any given phthalate. Rodent studies support that phthalates may act as adjuvants at levels likely to be relevant for environmental exposures, inducing respiratory and inflammatory effects in the presence of an allergen. Cell culture studies demonstrate that phthalates may alter the functionality of innate and adaptive immune cells. However, due to limitations of the applied exposure methods and models in experimental studies, including the diversity of phthalates, exposure routes, and allergic diseases considered, the support provided to the epidemiological findings is fragmented. Nevertheless, the current evidence points in the direction of concern. Further research is warranted to identify the most critical windows of exposure, the importance of exposure pathways, interactions with social factors, and the effects of co-exposure to phthalates and other environmental contaminants.