Phthalate metabolites in urine and asthma, allergic rhinoconjunctivitis and atopic dermatitis in preschool children

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.

Exposure to phthalate increases the risk of eczema in children: Findings from a systematic review and meta-analysis

Emerging evidence indicated phthalate exposure might raise the risk of eczema in children. However, these findings were inconsistent. The relation between phthalate exposure and childhood eczema remained debated. Therefore, we performed this meta-analysis to assess their association. PubMed, Web of Science, and Embase were searched for eligible studies. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated for risk estimate. Thirty studies involving 12,615 participants were included in this meta-analysis. For prenatal phthalate exposure assessed with maternal samples, the pooled results showed gestational exposure to monobenzyl phthalate (MBzP) (OR: 1.17, 95% CI: 1.00-1.36), but not the other phthalates, was correlated with increased risk of eczema in children. For childhood exposure assessed using children's urine sample, our pooled results indicated that postnatal exposure to MBzP (OR: 1.10, 95% CI: 1.02-1.19), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) (OR: 1.32, 95% CI: 1.08-1.61), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) (OR: 1.24, 95% CI: 1.06-1.44), and molar summation of di-2-ethylhexyl phthalate (DEHP) (OR: 1.23, 95% CI: 1.06-1.42) were associated with higher risk of eczema. While for studies using household dust to estimate environmental phthalate exposure and eczema risk, the pooled results showed no significant association. Subgroup analyses indicated study country, diagnostic mode, and children's age contributed to the heterogeneity. The results of our meta-analysis demonstrated that phthalate exposure during both prenatal and postnatal periods was associated with elevated risk of eczema in children. However, such association was not strong as the pooled ORs were relatively small. Further studies are warranted to verify these findings and explore the underlying mechanism.

Phthalate Metabolites in Urine of Chinese Children and Their Association with Asthma and Allergic Symptoms

Phthalates are ubiquitous 'modern' chemical compounds with potential negative impacts on children's health. A nested case-control study was designed to investigate associations of phthalate exposure with children's asthma and allergic symptoms. We collected 243 first morning urine samples from 4-8-year-old children in Tianjin, China. Eight metabolites (i.e., mono-ethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP) and mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-carboxylpentyl) phthalate (MECPP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP)) of five phthalates were analyzed using HPLC-MS. MiBP, MnBP and MECPP were the dominant phthalate metabolites in urine of children in Tianjin with median concentrations of 31.6 μg/L, 26.24 μg/L and 46.12 μg/L, respectively. We found significantly positive associations of diagnosed asthma with MnBP (adjusted odds ratios (AOR): 1.96; 95% confidence intervals (CIs): 1.07-3.61), MEHHP (AOR: 2.00; 95% CI: 1.08-3.71) and MEOHP (AOR: 2.09; 95% CI: 1.06-4.10). Our study indicates that phthalate exposure in childhood, especially to di-n-butyl phthalate (DnBP) and di(2-ethylhexyl) phthalate (DEHP), may be a risk factor for children's asthma.

National-scale urinary phthalate metabolites in the general urban residents involving 26 provincial capital cities in China and the influencing factors as well as non-carcinogenic risks

Phthalates (PAEs) are widely used in daily products but can cause a variety of adverse effects in humans. Few studies have been carried out on human internal exposure levels of PAEs on a large-scale, especially in developing countries. In the present study, 1161 urine samples collected from residents of 26 provincial capitals in China were analyzed for nine phthalate metabolites (mPAEs). The chemicals were widely detected, and the median specific gravity adjusted urinary concentration of Σ₉mPAEs was 278 μg/L. Di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the main parent PAEs that the residents were exposed to. Demographic characteristics, such as age and educational level, were significantly associated with PAE exposure. Children and the elderly had higher mPAE levels. Subjects with lower educational levels were more frequently exposed to DnBP and DEHP. However, mono-ethyl phthalate showed the opposite trend, i.e., higher concentrations in subjects aged 18-59 years and with higher educational levels. Geographic differences were detected at the national scale. Residents in northeastern and western China had higher levels of mPAEs than those in central China, most likely because of different industrial usage of the chemicals and different living habits and living conditions of the residents. Health risk assessment showed that hazard indices of PAEs ranged from 0.07 to 9.34, with 20.0% of the subjects being concern for potential non-carcinogenic risk as assessed by Monte Carlo simulation. DEHP and DnBP were the primary contributors, representing 96.7% of total risk. This first large-scale study on PAE human internal exposure in China provides useful information on residents' health in a developing country, which could be used for chemical management and health protection.

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.

Identification of Phthalates from Artificial Products in Chinese Kindergarten Classrooms and the Implications for Preschool Children's Exposure Assessments

Phthalates are typical chemical pollutants in kindergarten classrooms since numerous artificial products (e.g., polyvinyl chloride (PVC) floorings, soft polymers and plastic toys) that might contain phthalates are widely distributed in kindergarten classrooms. Although Chinese preschool children spend a considerable amount of their waking hours (>8 h/day) in kindergartens, phthalate exposure in such indoor environment has not been given much attention. In this study, the mass fractions of six phthalates in twenty-six artificial products (fifteen flat decoration materials and eleven plastic toys) commonly found in Chinese kindergarten classrooms were measured. Di-2-ethylhexyl phthalate (DEHP) was the most predominant compound in all materials. The emission characteristics of the DEHP from these materials were further investigated. The measured emission characteristics were used for predicting multi-phase DEHP concentrations in kindergarten classrooms by applying a mass transfer model. The modeled concentrations were comparable with those measured in the real environment, indicating that these products might be the major sources of DEHP in Chinese kindergarten classrooms. Preschool children’s exposure to DEHP was found to be 0.42 μg/kg/day in kindergartens under baseline conditions, accounting for 18% of the total exposure to DEHP in Chinese indoor environments.

Phthalate Exposure and Oxidative/Nitrosative Stress in Childhood Asthma: A Nested Case-Control Study with Propensity Score Matching

Whether low-dose phthalate exposure triggers asthma among children, and its underlying mechanisms, remain debatable. Here, we evaluated the individual and mixed effects of low-dose phthalate exposure on children with asthma and five (oxidative/nitrosative stress/lipid peroxidation) mechanistic biomarkers—8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO₂Gua), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), 8-isoprostaglandin F2α (8-isoPF2α), and malondialdehyde (MDA)—using a propensity score-matched case-control study (case vs. control = 41 vs. 111). The median monobenzyl phthalate (MBzP) concentrations in the case group were significantly higher than those in the control group (3.94 vs. 2.52 ng/mL, p = 0.02), indicating that dust could be an important source. After adjustment for confounders, the associations of high monomethyl phthalate (MMP) (75th percentile) with 8-NO₂Gua (adjusted odds ratio (aOR): 2.66, 95% confidence interval (CI): 1.03–6.92) and 8-isoPF2α (aOR: 4.04, 95% CI: 1.51–10.8) and the associations of mono-iso-butyl phthalate (MiBP) with 8-isoPF2α (aOR: 2.96, 95% CI: 1.13–7.79) were observed. Weighted quantile sum regression revealed that MBzP contributed more than half of the association (56.8%), followed by MiBP (26.6%) and mono-iso-nonyl phthalate (MiNP) (8.77%). Our findings supported the adjuvant effect of phthalates in enhancing the immune system response.

Urinary levels of phthalate, bisphenol, and paraben and allergic outcomes in children: Korean National Environmental Health Survey 2015-2017

BACKGROUND

Phthalates, bisphenols and parabens have been widely used in household and personal-care products. Their endocrine disrupting, sensitizing and antimicrobial properties might play a role in the occurrence of allergic diseases. However, the effects of these chemicals, particularly on humans, are relatively underexplored.

OBJECTIVES

This study aimed to report the concentrations of phthalate, bisphenol and paraben in urine of Korean children, and assess their relationship with allergic outcomes.

METHODS

Data obtained from nationally representative Korean children, a total of 1458 children between 3 and 11 years of age recruited in the Korean National Environmental Health Survey (3 rd round of KoNEHS 2015-2017), were analyzed. Associations of urinary phthalate metabolites, bisphenols, and parabens levels with atopic dermatitis and allergic rhinitis was examined by grouped into preschool (aged 3-5 years) and school children (aged 6-11 years). Allergic outcomes were obtained through questionnaires answered by their caregivers.

RESULTS

Atopic dermatitis was associated with urinary metabolites of DEHP, BzBP, DINP, and DIDP, and MeP and PrP in preschool children, BPA and PrP in school children. Allergic rhinitis was associated with MeP and PrP in preschool children, and metabolites of DEHP, MeP and PrP in school children. The association of urinary chemicals with atopic dermatitis and allergic rhinitis were different by gender, especially in preschool children.

CONCLUSION

Urinary phthalates, BPA and parabens levels in the Korean children were related with atopic dermatitis and allergic rhinitis. Considering the importance of allergic diseases in children, the public health implications of exposure to these chemicals warrant further studies. Given the cross-sectional design and confounding variables, the results of this study should be interpreted with caution.

Phthalates mixture on allergies and oxidative stress biomarkers among children: The Hokkaido study

BACKGROUND

Exposure to individual phthalates and the mediation effect of oxidative stress in association with asthma and allergic symptoms have been studied previously. Little is known about the mixture effect of phthalates on health outcomes. Thus, we investigated the effect of a mixture of ten phthalate metabolites in association with wheeze, rhino-conjunctivitis, and eczema. The mediating effect of three oxidative stress biomarkers was also assessed.

METHODS

Levels of 10 phthalate metabolites and 3 oxidative stress biomarkers were measured in 386 urine samples from 7-year-old children. Parents reported demographic and allergic symptoms using ISAAC questionnaires. Logistic regression for individual metabolites and mixture analysis weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) were fitted to examine the association between phthalate metabolite exposure and health outcomes. Baron and Kenny's regression approach was used for mediation analysis.

RESULTS

In logistic regression model showed mono (2-ethyl-5-carboxypentyl) phthalate (MECPP) (OR = 1.41, 95% CI 1.02-1.97) and mono carboxy-isononyl phthalate (cx-MINP) (OR = 1.40, 95% CI 1.07-1.86) were associated with wheeze. The WQS index had a significant association (OR = 1.46, 95% CI 1.09-1.96) with wheeze and (OR = 1.40, 95% CI 1.07-1.82) with eczema. Mono-isononyl phthalate (MINP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) were the most highly weighted metabolites. In the BKMR model, diisononyl phthalate (DINP) metabolites showed the highest group posterior inclusion probability (PIP). Among DINP metabolites, MINP in wheeze, cx-MINP in rhino-conjunctivitis and OH-MINP in eczema showed the highest conditional PIPs. The overall metabolites mixture effect was associated with eczema. We did not find any mediation of oxidative stress in the association between phthalates and symptoms. No significant association between phthalate metabolites and oxidative stress was observed in this study.

CONCLUSION

Mixture of phthalate metabolites were associated with wheeze and eczema. The main contributors to the association were DEHP and DINP metabolites. No mediation of oxidative stress was observed.

Analysis and health risk assessment of phthalate esters (PAEs) in indoor dust of preschool and elementary school centers in city of Tehran, Iran

Individuals spend a lot of time indoors; thus they are generally exposed to phthalates used in consumer products. Therefore, those exposed to phthalates as indoor contaminants are at high risks. The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazard of phthalate esters (PAEs), like dimethyl phthalate, diethyl phthalate, di(nbutyl) phthalate, butyl benzyl phthalate, dioctyl phthalate, and di(2-ethylhexyl) phthalate in the dust obtained from 21 schools in Tehran, in 2019. A total of 63 indoor dust specimens were obtained by a vacuum cleaner. After transferring dust samples to the laboratory, 100 mg of each sample was centrifuged and mixed with 20 ml acetone and kept through a night and ultrasonicated within 30 min. Eventually, PAEs' contents were measured via gas chromatography-mass spectrometry. Based on the findings, median concentrations of DMP, DEP, DnBP, BBP, DEHP, and DnOP were 0.90, 0.10, 6.0, 0.20, 118.30, and 4.10 mg kg^-1 respectively. Moreover, the overall average daily exposure doses (ADD) of phthalate esters via dust ingestion, skin contact, and inhalation were 1.56E-03, 1.70E-06, and 1.56E-07 mg kg^-1 day^-1, respectively, and the lifetime average daily exposure doses (LADD) were 1.83E-04, 2.34E-08, and 2.46E-08 mg kg^-1 day^-1, respectively; thus ingestion of dust particles was found to be the main pathway of exposure to phthalate for non-carcinogenic and carcinogenic risks. Although based on the results, the studied samples were below the US Environmental Protection Agency threshold of 1.00E-06, due to the disadvantages of phthalates in human safety, these kinds of investigations are helpful in understanding the main ways of exposure to PAEs and providing a science-based framework for the future attempts for mitigating the PAEs indoor emissions.

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.

A critical review on human internal exposure of phthalate metabolites and the associated health risks

Phthalates (PAEs) are popular synthetic chemicals used as plasticizers and solvents for various products, such as polyvinyl chloride or personal care products. Human exposure to PAEs is associated with various diseases, resulting in PAE biomonitoring in humans. Inhalation, dietary ingestion, and dermal absorption are the major human exposure routes. However, estimating the actual exposure dose of PAEs via an external route is difficult. As a result, estimation by internal exposure has become the popular analytical methods to determine the concentrations of phthalate metabolites (mPAEs) in human matrices (such as urine, serum, breast milk, hair, and nails). The various exposure sources and patterns result in different composition profiles of PAEs in biomatrices, which vary from country to country. Nevertheless, the mPAEs of diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP), and di-(2-ethylhexyl) phthalate (DEHP) are predominant in the urine. These mPAEs have greater potential health risks for humans. Children have been observed to exhibit higher exposure risks to several mPAEs than adults. Besides age, other influencing factors for phthalate exposure are gender, jobs, and residential areas. Although many studies have reported biological monitoring of PAEs, only a few reviews that adequately summarized the reports are available. The current review appraised available studies on mPAE quantitation in human biomatrices and estimated the dose and health risks of phthalate exposure. While some countries lack biomonitoring data, some countries' data do not reflect the current PAE exposure. Thence, future studies should involve frequent PAE biomonitoring to accurately estimate human exposure to PAEs, which will contribute to health risk assessments of human exposure to PAEs. Such would aid the formulation of corresponding regulations and restrictions by the government.

Associations among phthalate exposure, DNA methylation of TSLP, and childhood allergy

BACKGROUND

Dysregulation of thymic stromal lymphopoietin (TSLP) expressions is linked to asthma and allergic disease. Exposure to phthalate esters, a widely used plasticizer, is associated with respiratory and allergic morbidity. Dibutyl phthalate (DBP) causes TSLP upregulation in the skin. In addition, phthalate exposure is associated with changes in environmentally induced DNA methylation, which might cause phenotypic heterogeneity. This study examined the DNA methylation of the TSLP gene to determine the potential mechanism between phthalate exposure and allergic diseases.

RESULTS

Among all evaluated, only benzyl butyl phthalate (BBzP) in the settled dusts were negatively correlated with the methylation levels of TSLP and positively associated with children's respiratory symptoms. The results revealed that every unit increase in BBzP concentration in the settled dust was associated with a 1.75% decrease in the methylation level on upstream 775 bp from the transcription start site (TSS) of TSLP (β =  - 1.75, p = 0.015) after adjustment for child's sex, age, BMI, parents' smoking status, allergic history, and education levels, PM_2.5, formaldehyde, temperature; and relative humidity. Moreover, every percentage increase in the methylation level was associated with a 20% decrease in the risk of morning respiratory symptoms in the children (OR 0.80, 95% CI 0.65-0.99).

CONCLUSIONS

Exposure to BBzP in settled dust might increase children's respiratory symptoms in the morning through decreasing TSLP methylation. Therefore, the exposure to BBzP should be reduced especially for the children already having allergic diseases.

Phthalates: Relationships between Air, Dust, Electronic Devices, and Hands with Implications for Exposure

Exposure to phthalates is pervasive and is of concern due to associations with adverse health effects. Exposures and exposure pathways of six phthalates were investigated for 51 women aged 18-44 years in Ontario, Canada, based on measured phthalate concentrations in hand wipes and indoor media in their residences. All six phthalates had detection frequencies of 100% in air (∑₆670 ng m^-3 geomean) and floor dust (∑₆630 μg g^-1), nearly 100% detection frequencies for hand palms and backs that were significantly correlated and concentrations were repeatable over a 3 week interval. Phthalates on hands were significantly correlated with levels in air and dust, as expected according to partitioning theory. Total exposure was estimated as 4860 ng kg bw^-1 day^-1 (5th and 95th percentiles 1980-16 950 ng kg bw^-1 day^-1), with dust ingestion, followed by hand-to-mouth transfer, as the dominant pathways. With the exception of diethyl phthalate (DEP), phthalates had over 50% detection frequencies in surface wipes of most electronic devices sampled, including devices in which the use of phthalates was not expected. Phthalate concentrations on surfaces of hand-held devices were ∼10 times higher than on non-hand-held devices and were correlated with levels on hands. The data are consistent with phthalate emissions from sources such as laminate flooring and personal care products (e.g., scented candles), followed by partitioning among air, dust, and surface films that accumulate on electronic devices and skin, including hands. We hypothesize that hands transfer phthalates from emission sources and dust to hand-held electronic devices, which accumulate phthalates due to infrequent washing and which act as a sink and then a secondary source of exposure. The findings support those of others that exposure can be mitigated by increasing ventilation, damp cloth cleaning, and minimizing the use of phthalate-containing products and materials.

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.

Phthalate exposure in Chinese homes and its association with household consumer products

Phthalates are SVOCs (Semi-volatile Organic Compounds) that are widely used in industrial and daily home products. This study aimed to investigate exposure levels to phthalates in Chinese homes and to relate these to building characteristics and lifestyles. Dust in 399 homes of 410 children in urban Tianjin and rural Cangzhou was analyzed for concentrations of six target phthalates. The median concentrations were 0.31μg/g for diethyl phthalate (DEP), 16.39μg/g for di-isobutyl phthalate (DiBP), 42.60μg/g for di-n-butyl phthalate (DnBP), 0.10μg/g for benzyl butyl phthalate (BBzP), 127.11μg/g for di (2-ethylhexyl) phthalate (DEHP) and 0.28μg/g for di-isononyl phthalate (DiNP). Strong associations were found between modern flooring materials (laminated wood/wood) and concentrations of DiBP, BBzP and DiNP; modern window frame (aluminum/plastic steel) and BBzP concentration; leather polish and DEHP concentration; perfume and DEP concentration. Concentrations of phthalates were significantly higher in Tianjin urban homes than Cangzhou rural homes. Concentrations of phthalates increased significantly with increasing household income. Our study indicates that exposure to phthalates in Chinese homes increases with attributes of modern life.

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

BACKGROUND

Phthalates are ubiquitously found in numerous environments and have been related to a variety of adverse health effects. Previous studies have suggested that phthalate exposure is associated with asthma risk in humans; however, such findings are inconsistent.

METHODS

The aim of the present meta-analysis was to clarify the association between phthalate exposure and asthma risk. A literature search was conducted using PubMed, EMBASE and Web of Science for relevant studies published up to January 5, 2020. Fixed-effects or random-effects models were applied to combine the results, and several subgroup analyses were used to explore the sources of heterogeneity.

RESULTS

A total of 14 studies containing more than 14,000 participants were included in the present study. A positive, significant association between mono-benzyl phthalate (MBzP) levels and asthma risk was found, and the overall odds ratio (OR) was 1.17 (95% confidence interval [CI]: 1.06-1.28, P-value for overall effect [P_z] = 0.001), with a low heterogeneity (P-value for heterogeneity [P_het] = 0.193, I² = 23.6%). The pooled ORs for mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) concentrations were 1.13 (95% CI: 1.03-1.24, P_z = 0.011) and 1.20 (95% CI: 1.00-1.42, P_z = 0.045), respectively. Children with high levels of MBzP or mono-(carboxynonyl) phthalate (MCNP) were suggested to have increased odds of asthma compared to older populations. In the subgroup analysis by study location, an increased risk for asthma in relation to levels of the sum of di-2-ethylhexyl phthalate (ΣDEHP) was observed in European studies (OR = 1.16, 95% CI: 1.00-1.34, P_z = 0.048) compared to Asia and North America.

CONCLUSIONS

Urinary levels of MBzP, MEHHP, MECPP, MCNP, and DEHP were positively related to asthma risk. No significant association was observed for the other phthalate metabolites in relation to asthma risk. Further research is needed to verify these findings and shed light on the molecular mechanism by which phthalates are associated with asthma.

Multiple Stressor Effects of Radon and Phthalates in Children: Background Information and Future Research

The present paper reviews available background information for studying multiple stressor effects of radon (222Rn) and phthalates in children and provides insights on future directions. In realistic situations, living organisms are collectively subjected to many environmental stressors, with the resultant effects being referred to as multiple stressor effects. Radon is a naturally occurring radioactive gas that can lead to lung cancers. On the other hand, phthalates are semi-volatile organic compounds widely applied as plasticizers to provide flexibility to plastic in consumer products. Links of phthalates to various health effects have been reported, including allergy and asthma. In the present review, the focus on indoor contaminants was due to their higher concentrations and to the higher indoor occupancy factor, while the focus on the pediatric population was due to their inherent sensitivity and their spending more time close to the floor. Two main future directions in studying multiple stressor effects of radon and phthalates in children were proposed. The first one was on computational modeling and micro-dosimetric studies, and the second one was on biological studies. In particular, dose-response relationship and effect-specific models for combined exposures to radon and phthalates would be necessary. The ideas and methodology behind such proposed research work are also applicable to studies on multiple stressor effects of collective exposures to other significant airborne contaminants, and to population groups other than children.

Combined exposure to phthalate esters and phosphate flame retardants and plasticizers and their associations with wheeze and allergy symptoms among school children

BACKGROUND

Phthalate esters and phosphate flame retardants and plasticizers (PFRs) are both used as plasticizers and are commonly detected in indoor environments. Although both phthalates and PFRs are known to be associated with children's wheeze and allergic symptoms, there have been no previous studies examining the effects of mixtures of these exposures.

OBJECTIVES

To investigate the association between exposure to mixtures of phthalate esters and PFRs, and wheeze and allergic symptoms among school-aged children.

METHODS

A total of 128 elementary school-aged children were enrolled. Metabolites of 3 phthalate esters and 7 PFRs were measured in urine samples. Parent-reported symptoms of wheeze, rhinoconjunctivitis, and eczema were evaluated using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. In the primary model, we created a phthalate ester and PFR mixture exposure index, and estimated odds ratios (ORs) using weighted quantile sum (WQS) regression and quantile g (qg)-computation. The two highest chemicals according to qg-computation weight %s were combined to create a combination high × high exposure estimate, with ORs calculated using the "low × low" exposure group as the reference category. Concentrations of each metabolite were corrected by multiplying this value by the sex- and body size-Standardised creatinine concentration and dividing by the observed creatinine value. All models were adjusted for sex, grade, dampness index and annual house income.

RESULTS

The odds ratio of rhinoconjunctivitis for the association between exposure to chemical mixtures according to the WQS index positive models was; OR = 2.60 (95% confidence interval [CI]: 1.38-5.14). However, wheeze and eczema of the WQS index positive model, none of the WQS index negative models or qg-computation result yielded statistically significant results. Combined exposure to the two highest WQS weight %s of "high-high" ΣTCIPP and ΣTPHP was associated with an increased prevalence of rhino-conjunctivitis, OR = 5.78 (1.81-18.43) to the "low × low" group.

CONCLUSIONS

Significant associations of mixed exposures to phthalates and PFRs and increased prevalence of rhinoconjunctivitis was found among elementary school-aged children in the WQS positive model. Mixed exposures were not associated with any of allergic symptoms in the WQS negative model or qg-computation approach. However, the combined effects of exposure to two PFRs suggested an additive and/or multiplicative interaction, potentially increasing the prevalence of rhinoconjunctivitis. A further study with a larger sample size is needed to confirm these results.

Longitudinal effect of phthalates exposure on allergic diseases in children

BACKGROUND

Environmental chemicals, such as phthalates, phenols, and parabens, may affect children's immune development and contribute to the risk of atopic diseases and asthma.

OBJECTIVE

To evaluate the associations between prenatal and childhood phthalate exposure and atopic diseases in children at the age of 9 years.

METHODS

This analysis is restricted to 145 mother-child pairs from the prospective Polish Mother and Child Cohort Study. Phthalate metabolite levels were assessed in the urine samples collected from mothers during the third trimester of pregnancy and from children at age of 2 and 9 years. For the appropriate recognition of children's health status, a questionnaire was administered to the mothers and completed with information from the medical record of each child. The clinical examination was performed by a pediatrician/allergist in the presence of the mother or a relative.

RESULTS

A higher urine concentration of mono-2-ethyl-5-oxohexyl phthalate increased the risk of food allergy in children at the age of 9 years (odds ratio [OR], 1.75; 95% CI, 1.19-2.57; P = .004) and decreased the risk of atopic dermatitis (OR, 0.49; 95% CI, 0.27-0.87; P = .02). For mono-2-ethyl-5-hydroxyhexyl phthalate, an increased risk of atopic dermatitis was observed (OR, 1.90; 95% CI, 1.18-3.05; P = .008). A higher urine concentration of mono-benzyl phthalate increased the risk of asthma in children (OR, 1.67; 95% CI, 1.08-2.58; P = .02), but the risk of asthma decreased when the concentration of mono-2-ethylhexyl phthalate was higher (OR, 0.64; 95% CI, 10.43-0.97; P = .04).

CONCLUSION

Our study has not provided clear evidence of the negative effect of phthalate exposure during pregnancy and within the 9 years after birth on allergic diseases in children.

Early life exposure to phthalates in the Canadian Healthy Infant Longitudinal Development (CHILD) study: a multi-city birth cohort

BACKGROUND

Few studies have examined phthalate exposure during infancy and early life, critical windows of development. The Canadian Healthy Infant Longitudinal Development (CHILD) study, a population-based birth cohort, ascertained multiple exposures during early life.

OBJECTIVE

To characterize exposure to phthalates during infancy and early childhood.

METHODS

Environmental questionnaires were administered, and urine samples collected at 3, 12, and 36 months. In the first 1578 children, urine was analyzed for eight phthalate metabolites: mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-3-carboxypropyl phthalate (MCPP). Geometric mean (GM) concentrations were calculated by age, together with factors that may influence concentrations. Trends with age were examined using mixed models and differences within factors examined using ANOVA.

RESULTS

The highest urinary concentration was for the metabolite MBP at all ages (GM: 15-32 ng/mL). Concentrations of all phthalate metabolites significantly increased with age ranging from GM: 0.5-15.1 ng/mL at 3 months and 1.9-32.1 ng/mL at 36 months. Concentrations of all metabolites were higher in the lowest income categories except for MEHP at 3 months, among children with any breastfeeding at 12 months, and in urine collected on dates with warmer outdoor temperatures (>17 °C), except for MBzP at 3 months and MEHP at 3 and 12 months. No consistent differences were found by gender, study site, or maternal age.

CONCLUSIONS

Higher phthalate metabolite concentrations were observed among children in lower income families. Examination of factors associated with income could inform interventions aimed to reduce infant phthalate exposure.

Concentration of phthalate esters in indoor and outdoor dust in Kocaeli, Turkey: implications for human exposure and risk

The interest in phthalate esters (PAEs) has increased in recent years because elevated phthalate levels have been detected in environmental matrices and they have certain adverse effects on human health. Indoor dust from 90 homes and outdoor (street) dust from outside these homes were collected in Kocaeli province between February and April 2016 and analyzed for eight PAEs. The total indoor dust concentrations of eight PAEs (Σ₈PAEs) ranged from 21.33 μg g^-1 to 1802 μg g^-1 (median, 387.67 μg g^-1), significantly higher than outdoor dust concentrations (0.16-36.85 μg g^-1 with median 4.84 μg g^-1). Di-2-ethylhexyl phthalate (DEHP) was the most dominant pollutant in both indoor and outdoor environments with a median value of 316.02 μg g^-1 and 3.89 μg g^-1, respectively, followed by di-n-butyl phthalate and butylbenzyl phthalate (BBP). DEHP was measured within the range of 198.54-816.92 μg g^-1 and BBP within the range of 15.52-495.33 μg g^-1 in homes with PVC coating, significantly higher than the levels in homes with parquet and tiled floor (p<0.05). Monte Carlo simulation was applied to probabilistically estimate exposure to PAEs and associated carcinogenic risk. The Σ₅PAE median values of non-dietary ingestion and dermal absorption exposure were estimated as 1.57 μg kg day^-1 and 0.007 μg kg day^-1 for children and 0.09 μg kg day^-1 and 0.04 μg kg day^-1 for adults while inhalation route exposure to PAE in dust was at a negligible level for both groups. Children were more exposed to PAEs through ingestion route (92.74% to 99.54% of the total exposure) while adult exposure through ingestion routes (62-68.4%) and dermal absorption (29.74% and 31.87% of the total exposure) were comparable. The mean cancer risk level via non-dietary ingestion of DEHP for children was 2.33×10^-6, about eight times higher than the levels for adults. The risk levels of about 16% of adults and 95% of children are greater than the threshold value of 10^-6 when the population is exposed to DEHP in indoor dust. Looking from the viewpoint of child health, the most effective method to reduce exposure among the measured PAEs is to keep the release of DEHP under control, especially in indoor environment, and to take precautions to reduce exposure.

PM2.5 bound phthalates in four metropolitan cities of China: Concentration, seasonal pattern and health risk via inhalation

Phthalates (PAEs) are in a group of artificial chemicals with potential adverse effects to human health and they can be frequently detected in environmental matrices due to its extensive usage. However, seasonal patterns of concentrations in atmosphere and risks posed by PAEs in airborne PM_2.5 to Chinese population have not been well characterized. During the period of November 2015 to March 2017, samples of fine particulate matter (PM_2.5) were collected in four cities of Guangzhou, Shanghai, Beijing and Harbin, which are major metropolitan areas of various latitudes of China. Concentrations of fourteen PAEs in airborne PM_2.5 were quantified using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Estimated daily intakes (EDIs), hazard quotients (HQs) and hazard index (HI) were calculated. Lifetime average daily doses (LADD) and incremental lifetime cancer risks (ILCR) of di(2-ethylhexyl) phthalate (DEHP) for four age groups, which divide with infant, toddler, adolescent and adult, by inhalation route were evaluated. Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Di-n-butyl phthalate (DBP), and DEHP were the four major PAEs contaminants in these PM_2.5 samples. The sum concentrations of DMP, DEP, DBP and DEHP in Guangzhou, Shanghai, Beijing and Harbin ranged from 32.5-76.1, 10.1-101, 8.02-107 and 13.5-622 ng/m³, with mean concentrations of 59.1, 50.8, 43.8 and 136 ng/m³, respectively. The concentration of total PAEs in PM_2.5 from higher latitudes city (Harbin) was higher than those from lower latitudes cities (Guangzhou and Shanghai). Total concentrations of PAEs were significantly higher during warmer seasons than those during colder seasons among the four cities. Although the EDIs, HQs, and HI for all age groups were less than the threshold set by the U.S. Environmental Protection Agency (US EPA) and European Food Safety Authority (EFSA), the highest values of 70-years ILCR from Shanghai and Harbin were 1.2 × 10^-6 and 1.3 × 10^-6, which were slightly beyond the acceptable level of 10^-6. These findings reveal that the cancer risks of DEHP bound to PM_2.5 in these two cites should be of particular concern.

Urinary phthalate metabolites in relation to childhood asthmatic and allergic symptoms in Shanghai

BACKGROUND

Few studies can be found on phthalate exposure in relation to childhood asthma and allergic symptoms from Mainland China, where a persistent increase in prevalence of childhood asthma and allergic disease has been observed.

OBJECTIVES

This study aimed to assess the exposure levels to phthalates and its relationship with asthmatic and allergic symptoms among children in Shanghai, which has the highest prevalence of childhood asthma in Mainland China.

METHODS

A follow-up study (2013-2014) of 434 children aged 5-10 years was conducted, based on the China, Children, Homes, Health (CCHH) study (2011-2012) in Shanghai, China. Information on asthmatic and allergic symptoms (wheeze, rhinitis, and eczema) were collected using validated questionnaires. Ten phthalate metabolites in morning urine samples were analyzed by high-performance liquid chromatography with triple quadrupole tandem mass spectrometry (HPLC-MS/MS). Multivariable logistic regression was used to estimate the associations between symptoms and urinary phthalate metabolites controlling for demographics, family history of allergic diseases and other covariates.

RESULTS

Nine out of 10 phthalate metabolites were detected in all subjects (average detection rate of 93.2%). By multivariable logistic regression analyses, the 4th quartile of Mono‑n‑butyl phthalate (MnBP) (reference: 1st quartile) had adjusted prevalence odds ratios (aPOR_S) and 95% confidence intervals (95%CIs) of 2.27(1.06-4.88), 2.14(1.02-4.46) and 2.98(1.19-7.50) for wheeze, rhinitis and eczema, respectively, while those of Mono‑isobutyl phthalate (MiBP) were 2.23(1.08-4.62) and 2.96(1.02-8.60) for rhinitis and eczema, respectively. The highest quartile of mono‑2‑ethyl‑5‑hydroxyhexyl phthalate(MEHHP) and mono‑2‑ethyl‑5‑oxohexyl phthalate(MEOHP) had aPOR_S and 95%CIs of 3.10(1.10-8.74) and 2.63(1.02-6.80) for eczema, respectively. By summing up the 4 low molecular weight metabolites (∑₄LMWP) and all 9 metabolites (∑₉Total), the highest quartiles of ∑₄LMWP and∑₉Total were significantly associated with all symptoms. In most of the above associations, a significantly increasing trend from the 1st to the 4th quartile was observed. Subjects with 2 or 3 concomitant symptoms (reference: no symptoms) had significant positive associations with a higher level (the 4th quartile) of phthalate metabolites.

CONCLUSIONS

Low MW metabolites such as MnBP and MiBP, high MW DEHP and the total amount of phthalate metabolites might have adverse health effects on asthma and allergic symptoms in Chinese children.

Phthalates and organophosphates in settled dust and HVAC filter dust of U.S. low-income homes: Association with season, building characteristics, and childhood asthma

Phthalates and organophosphates are ubiquitous indoor semi-volatile organic contaminants (SVOCs) that have been widely used as plasticizers and flame retardants in consumer products. Although many studies have assessed their levels in house dust, only a few used dust samples captured by filters of building heating, ventilation, and air conditioning (HVAC) systems. HVAC filters collect particles from large volumes of air over a long period of time (potentially known) and thus provide a spatially and temporally integrated concentration. This study measured concentrations of phthalates and organophosphates in HVAC filter dust and settled floor dust collected from low-income homes in Texas, United States, in both the summer and winter seasons. The most frequently detected compounds were benzyl butyl phthalate (BBzP), di-(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DnOP), tris (1-chloro-2-propyl) phosphate (TCIPP), triphenyl phosphate (TPHP), and tris (1,3-dichloroisopropyl) phosphate (TDCIPP). The median level of TCIPP in settled dust was 3- to 180-times higher than levels reported in other studies of residential homes. Significantly higher concentrations were observed in HVAC filter dust as compared to settled dust for most of the frequently detected compounds in both seasons, except for several phthalates in the winter. SVOC concentrations in settled dust in winter were generally higher than in summer, while different seasonality patterns were found for HVAC filter dust. Settled dust samples from homes with vinyl flooring contained significantly higher levels of BBzP and DEHP as compared to homes with other types of floor material. The concentration of DEHP and TDCIPP in settled dust also significantly associated with the presence of carpet in homes. Cleaning activities to remove dust from furniture actually increased the levels of certain compounds in HVAC filter dust, while frequent vacuuming of carpet helped to decrease the concentrations of some compounds in settled dust. Additionally, the size and age of a given house also correlated with the levels of some pollutants in dust. A statistically significant association between DEHP concentration in HVAC filter dust in summer and the severity of asthma in children was observed. These results suggest that HVAC filter dust represents a useful sampling medium to monitor indoor SVOC concentrations with high sensitivity; in contrast, when using settled dust, in addition to consideration of seasonal influences, it is critical to know the sampling location because the type and level of SVOCs may be related to local materials used there.

Exposure to a combination of formaldehyde and DINP aggravated asthma-like pathology through oxidative stress and NF-κB activation

Several epidemiological and experimental studies indicate a positive association between exposure to formaldehyde or phthalates and allergic asthma. However, nothing is yet known about the effects of exposure to formaldehyde and phthalates together, nor the role of each on allergic asthma. Here, we investigated the effects of a combined exposure to formaldehyde and diisononyl phthalate (DINP) on asthma-like pathology in mice, and determined the underlying mechanisms implicated in NF-κB and ROS. Mice were exposed to formaldehyde and/or DINP and sensitization with OVA. The results showed that exposure to 1.0 mg/m³ formaldehyde or 20 mg/kg·d DINP slightly aggravated the airway wall remodeling, promoted the production of IgE and IgG1, and induced the occurrence of airway hyperresponsiveness (AHR). However, these pathological responses and AHR were greatly exacerbated by the combined exposure to formaldehyde and DINP. Administering melatonin to block oxidative stress, alleviated the pathological responses and AHR induced by formaldehyde and DINP, and inhibited the activation of the NF-κB and the secretion of TSLP. Blocking NF-κB with Dehydroxymethylepoxyquinimicin, inhibited the elevation of TSLP expression and Th2/Th17 cytokine secretion, and effectively alleviated the allergic asthma-like symptoms. The results suggested that exposure to both formaldehyde and DINP aggravated hypersensitivity asthma symptoms by promoting oxidative stress and activating NF-κB. These findings expand our understanding of how formaldehyde and DINP exposure affect the development of allergic asthma.

Effects of prenatal di(2-ethylhexyl) phthalate exposure on childhood allergies and infectious diseases: The Hokkaido Study on Environment and Children's Health

Phthalates are widely used in consumer products, and experimental studies suggest that exposure to phthalates increase the risk of allergies. However, epidemiologic evidence on the associations between prenatal phthalate exposure and allergies/infectious diseases and cord blood immunoglobulin E (IgE) levels is limited. This study aimed to evaluate the associations between maternal mono(2-ethylhexyl) phthalate (MEHP) levels and cord blood IgE levels at birth (n=127), as well as the risk of allergies/infectious diseases in participants up to 7years of age; the participants were 1.5 (n=248), 3.5 (n=222), 7 (n=184) years of age. Maternal blood MEHP level in the second trimester was measured using gas chromatography-mass spectrometry. Participant characteristics were obtained from the medical birth records and self-administered questionnaires during pregnancy and after delivery. Wheeze and eczema were defined according to the Japanese version of the International Study of Asthma and Allergies in Childhood and the American Thoracic Society-Division of Lung Diseases questionnaire, respectively. Infectious diseases were defined using questionnaires for each specified age. To evaluate the associations between maternal MEHP and allergies or infectious diseases, we used logistic regression analysis and generalized estimating equations analysis. Maternal MEHP levels were negatively associated with cord blood IgE levels and increased risks of allergies and infectious diseases up to 7years of age. This is the first study to investigate the effects of prenatal MEHP exposure on IgE levels at birth and allergies/infectious diseases up to 7years of age. Further epidemiological studies should focus on other phthalate metabolites and their health effects on larger populations.

Maternal exposure to environmental DEHP exacerbated OVA-induced asthmatic responses in rat offspring

Di (ethylhexyl) phthalate (DEHP) is a commonly used phthalates (PAEs) compound as plasticizer and becomes a severe environmental pollutant worldwide. Studies show that DEHP, as an environmental endocrine disruptor, has potential adverse effects on human. Epidemiologic studies indicate that DEHP is positively correlated to allergic diseases. Maternal exposure to DEHP may contribute to the increasing incidence of allergic diseases in offspring. However, the role of DEHP and its detailed mechanism in allergic disease of the offspring are still unclear. The aim of our study is to investigate whether DEHP maternal exposure could aggravate the allergic responses in offspring and its mechanism. Pregnant Wistar rats were randomly divided into three groups and exposed to different doses of DEHP. Half of the offspring were challenged with OVA after birth. All the pups of each group were sacrificed at postnatal day (PND)14, PND21 and PND28. The number of inflammatory cells in bronchoalveolar lavage was counted, lung pathological changes were observed, Th2 type cytokines expressions were checked, and the expression of TSLP signaling pathway were examined. Our results showed that maternal exposure to DEHP during pregnancy and lactation aggravated the eosinophils accumulation and the pathological inflammatory changes in pups' lung after OVA challenge. And maternal exposure to DEHP during pregnancy and lactation also elevated the levels of typical Th2 cytokines in OVA-challenged rats. What's more, maternal exposure to DEHP during pregnancy and lactation increased the levels of TSLP, TSLPR and IL-7R in the offspring after OVA challenge. Our study suggested that DEHP maternal exposure could aggravate the OVA-induced asthmatic responses in offspring. And this adjuvant effect of DEHP was related with the TSLP/TSLPR/IL-7R and its downstream signal pathways.

Prenatal Exposure to Phthalates and the Development of Eczema Phenotypes in Male Children: Results from the EDEN Mother-Child Cohort Study

BACKGROUND

Contradictory results exist regarding the importance of early-life exposure to phthalates for development of childhood eczema.

OBJECTIVES

We evaluated the association between maternal urinary concentrations of phthalate metabolites between the 24th and 28th week of gestation and occurrence of eczema in their sons up to 5 y of age, according to allergic sensitization as assessed by total immunoglobulin E (IgE) in a subsample of individuals.

METHODS

Data on health outcomes and background factors were collected using five standardized annual questionnaires completed by parents at the children's ages of 1-5 y, and their associations with phthalate metabolite urinary concentrations were assessed in 604 mother-son pairs with adjusted multiple logistic regression and Cox's survival model. Several eczema phenotypes were considered. Atopic status was assessed at 5 y of age in 293 boys through total IgE assessment.

RESULTS

At 5 y of age, the prevalence of ever eczema was 30.4%. Metabolites of di-isobutyl phthalate (DiBP) and di-isononyl phthalate (DiNP) were positively associated with early-onset (0-24 mo of age) eczema (15.7%) and late-onset (24-60 mo of age) eczema (14.7%). Applying the Cox's model showed a significant association of occurrence of eczema in the first 5 y of life with DiBP and DiNP metabolites. Among IgE-sensitized boys, metabolites of di-n-butyl phthalate (DBP) and DiBP were significantly associated with ever eczema {hazard ratio (HR)=1.67 [95% confidence interval (CI): 1.10, 2.54], p=0.01 and HR=1.87 (95% CI: 1.01, 3.48), p=0.04, respectively}.

CONCLUSIONS

Occurrence of eczema in early childhood may be influenced by prenatal exposure to certain phthalates in boys. Further investigations are needed to confirm this observation. https://doi.org/10.1289/EHP1829.

Phthalate esters and childhood asthma: A systematic review and congener-specific meta-analysis

INTRODUCTION

Exposure to phthalate esters (PAEs) has been associated with childhood asthma, but the congener-specific effects of PAEs on childhood asthma were unclear. We aimed to systematically review and meta-analyze observational studies on the associations between specific effects of PAEs and the risk of childhood asthma.

MATERIAL AND METHODS

Relevant studies were identified by searching three databases up to October 20, 2016. The reference lists of the retrieved articles were also reviewed. We included observational studies that reported risk estimates with 95% confidence intervals (CIs) for the associations between phthalate exposure and the risk of childhood asthma. Fixed-effects models were generally applied to calculate pooled risk estimates. When heterogeneity was present, random-effects models were applied.

RESULTS

A total of nine studies featuring 43 data points were included in our final meta-analyses. Results indicated that the benzyl butyl phthalate (BBzP) exposure had a significant association with the risk of childhood asthma. The Odd Ratios (ORs) were from 1.39 to 1.41 for different combination strategies. Subgroup analyses by different exposure period or samples used showed that prenatal exposure to BBzP had a stronger association with the risk of childhood asthma (OR = 1.38, 95% CI = 1.09-1.75), compared to those with postnatal exposure. Besides, the association was evident when the phthalate exposure was measured from dust samples. The OR for the associations between di-2-ethylhexyl phthalate (DEHP) in dust and childhood asthma was 2.71 (95% CI = 1.39-5.28), and 2.08 (95% CI = 1.10-3.92) for BBzP.

CONCLUSIONS

Our study suggested a positive association between DEHP and BBzP exposure and childhood asthma. Future studies are warranted to identify the underlying mechanisms of the association.

Exposure to phthalates in house dust and associated allergies in children aged 6-12years

Phthalates are widely used as plasticizers in household products. Several studies have reported an association between phthalate exposure and an increased risk of allergies. The present study estimated phthalate exposure in children aged 6-12years and assessed potential correlations with allergies. House dust samples were collected from floors and multi-surface objects >35cm above the floor. Urine samples were collected from the first morning void of the day. Daily phthalate intake (DI_dust and DI) was estimated using both house dust and urinary metabolite concentrations. Exposure to di-2-ethylhexyl phthalate (DEHP) in floor dust was associated with parental-reported rhino-conjunctivitis. After stratification by gender, this trend was found to only occur in boys. Furthermore, urinary mono-isobutyl phthalate was inversely associated with parental-reported wheeze in boys. DI_dust of benzyl butyl phthalate (BBzP) and DEHP were significantly correlated with DI_BBzP and DI_DEHP, respectively. These correlations were stronger with floor than with multi-surface dust. Our results suggest that, among Japanese children, house dust from low surfaces, such as living room floors, might play a meaningful role in the indoor environmental exposure pathway for BBzP and DEHP.

An imidazole-appended p-phenylene-Cu(II) ensemble as a chemoprobe for histidine in biological samples

A tetra-imidazole-appended tetrakis(p-phenylene)ethylene 1-Cu(2+) ensemble was found to enhance fluorescence upon addition of histidine, but not with any other amino acids. The 1-Cu(2+) ensemble also selectively detected proteins containing histidine residues in a mixture of water and methanol (90 : 10, v/v%). The 1-Cu(2+) ensemble-coated thin-layered chromatography (TLC) plate could also detect histidine quantitatively. Furthermore, the fluorescence emission recovery upon addition of five concentrations of His was ~80% with good linearity.

Prenatal exposure to environmental chemical contaminants and asthma and eczema in school-age children

BACKGROUND

Emerging evidence suggests that prenatal or early-life exposures to environmental contaminants may contribute to an increased risk of asthma and allergies in children. We aimed to the explore associations of prenatal exposures to a large set of environmental chemical contaminants with asthma and eczema in school-age children.

METHODS

We studied 1024 mother-child pairs from Greenland and Ukraine from the INUENDO birth cohort. Data were collected by means of an interview-based questionnaire when the children were 5-9 years of age. Questions from the ISAAC study were used to define asthma, eczema, and wheeze. We applied principal components analysis (PCA) to sixteen contaminants in maternal serum sampled during pregnancy, including perfluoroalkyl substances (PFASs), metabolites of diethylhexyl (DEHP) and diisononyl (DiNP) phthalates, PCB-153, and p,p'-DDE. Scores of five principal components (PCs) explaining 70% of the variance were included in multiple logistic regression models.

RESULTS

In a meta-analysis that included both populations, the PC2 score, reflecting exposure to DiNP, was negatively associated with current eczema (OR 0.71, 95% CI 0.52-0.96). Other associations were not consistent between the two populations. In Ukrainian children, the PC3 score (DEHP) was positively associated with current wheeze (adjusted OR 1.56, 95% CI 1.03-2.37), whereas the PC5 score, dominated by perfluorooctanoic acid (PFOA), was inversely associated with current wheeze (OR 0.64, 0.41-0.99). In Greenlandic children, a negative association of PC4 (organochlorines) with ever eczema (OR 0.78, 0.61-0.99) was found.

CONCLUSIONS

We found limited evidence to support a link between prenatal exposure to environmental chemical contaminants and childhood asthma and eczema.

Can exposure to environmental chemicals increase the risk of diabetes type 1 development?

Type 1 diabetes mellitus (T1DM) is an autoimmune disease, where destruction of beta-cells causes insulin deficiency. The incidence of T1DM has increased in the last decades and cannot entirely be explained by genetic predisposition. Several environmental factors are suggested to promote T1DM, like early childhood enteroviral infections and nutritional factors, but the evidence is inconclusive. Prenatal and early life exposure to environmental pollutants like phthalates, bisphenol A, perfluorinated compounds, PCBs, dioxins, toxicants, and air pollutants can have negative effects on the developing immune system, resulting in asthma-like symptoms and increased susceptibility to childhood infections. In this review the associations between environmental chemical exposure and T1DM development is summarized. Although information on environmental chemicals as possible triggers for T1DM is sparse, we conclude that it is plausible that environmental chemicals can contribute to T1DM development via impaired pancreatic beta-cell and immune-cell functions and immunomodulation. Several environmental factors and chemicals could act together to trigger T1DM development in genetically susceptible individuals, possibly via hormonal or epigenetic alterations. Further observational T1DM cohort studies and animal exposure experiments are encouraged.

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

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

Electrospun nanofibrous membranes incorporating an imidazole-appended p-phenylene-Cu(ii) ensemble as fluoroprobes for the detection of His-proteins

Tetra-imidazole-appendedp-phenylene-Cu(ii) doped nanofibrous membranes can function as “turn-on” portable fluorescence chemoprobes for Histidine.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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