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

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.

A systematic review of global distribution, sources and exposure risk of phthalate esters (PAEs) in indoor dust

Phthalate esters (PAEs) are a class of plasticizers that are readily released from plastic products, posing a potential exposure risk to human body. At present, much attention is paid on PAE concentrations in indoor dust with the understanding of PAEs toxicity. This study collected 8187 data on 10 PAEs concentrations in indoor dusts from 26 countries and comprehensively reviewed the worldwide distribution, influencing factors, and health risks of PAEs. Di-(2-ethylhexyl) phthalate (DEHP) is the predominant PAE with a median concentration of 316 μg·g-1 in indoor dust. Polyvinyl chloride wallpaper and flooring and personal care products are the main sources of PAEs indoor dust. The dust concentrations of DEHP show a downward trend over the past two decades, while high dust concentrations of DiNP are found from 2011 to 2016. The median dust contents of 8 PAEs in public places are higher than those in households. Moreover, the concentrations of 9 PAEs in indoor dusts from high-income countries are higher than those from upper-middle-income countries. DEHP in 69.8% and 77.8% of the dust samples may pose a potential carcinogenic risk for adults and children, respectively. Besides, DEHP in 16.9% of the dust samples may pose a non-carcinogenic risk to children. Nevertheless, a negligible risk was found for other PAEs in indoor dust worldwide. This review contributes to an in-depth understanding of the global distribution, sources and health risks of PAEs in indoor dust.

Phthalate ester levels in agricultural soils of greenhouses, their potential sources, the role of plastic cover material, and dietary exposure calculated from modeled concentrations in tomato

Soil samples collected from 50 greenhouses (GHs) cultivated with tomatoes (plastic-covered:24, glass-covered:26), 5 open-area tomato growing farmlands, and 5 non-agricultural areas were analyzed in summer and winter seasons for 13 PAEs. The total concentrations (Σ13PAEs) in the GHs ranged from 212 to 2484 ng/g, wheeas the concentrations in open-area farm soils were between 240 and 1248 ng/g. Σ13PAE in non-agricultural areas was lower (35.0 - 585 ng/g). PAE exposure through the ingestion of tomatoes cultivated in GH soils and associated risks were estimated with Monte Carlo simulations after calculating the PAE concentrations in tomatoes using a partition-limited model. DEHP was estimated to have the highest concentrations in the tomatoes grown in both types of GHs. The mean carcinogenic risk caused by DEHP for tomato grown in plastic-covered GHs, glass-covered GHs, and open-area soils were 2.4 × 10-5, 1.7 × 10-5 and 1.1 × 10-5, respectively. Based on Positive Matrix Factorization results, plastic material usage in GHs (including plastic cover material source for plastic-GHs) was found to be the highest contributing source in both types of GHs. Microplastic analysis indicated that the ropes and irrigation pipes inside the GHs are important sources of PAE pollution. Pesticide application is the second highest contributing source.

Dust phase and window film phase phthalates in dormitories: profile characteristics, source screening, and estimated gas-phase concentration and dermal exposure comparison

Recently, phthalate exposure has become a major public health concern. However, gaps still remain in our understanding of phthalate profile characteristics, source screening, and gas-phase estimation. This study measured phthalate concentrations in dust and window films in 101 dormitories at 13 universities in Beijing, China, from October to December 2019. Based on the phthalate concentrations in the dust and window films, we estimated the gas-phase phthalate concentrations using steady-state and instantaneous equilibrium models, respectively, and male and female students' dermal exposure using the Monte Carlo simulation. Commonly used materials and supplies were screened for phthalate sources and evaluated using the positive matrix factorization (PMF) model. The results showed that the detection frequency of ten phthalates ranged from 79.2 to 100% in dust and from 84.2 to 100% in window films. Dicyclohexyl phthalate (DCHP), di-(2-ethylhexyl) phthalate (DEHP), and dibutyl phthalate (DBP) were the most abundant phthalates in both indoor media and were also predominant in the indoor materials and supplies. The PMF results indicated that the potential sources of phthalates in dust and window films had both similarities and differences. Indoor door seals, paint, coatings, cables, air-conditioning rubber cable ties, wallpaper, and window seals were highly probable sources of phthalates. The gas-phase phthalate concentrations estimated using the two methods differed, especially for phthalates with high octanol-air partition coefficients (Koa), varying by 1-2 orders of magnitude. Moreover, compared with related studies, the gas-phase concentrations were significantly underestimated for phthalates with high Koa values, while the estimated gas-phase concentrations of phthalates with low Koa values were closer to the measured values. The estimated dermal exposure using the two methodologies also considerably differed. Such findings suggest that more attention should be focused on the exposure risk from the dust phase and window film phase phthalates.

Accumulation, sources, and health risks of phthalic acid esters (PAEs) in road dust from heavily industrialized, urban and rural areas in southern Iran

In this research, a total of 51 road dust samples were collected from three districts (Asaluyeh, Bushehr, and Goshoui) in the south of Iran from April to June 2022 and analyzed for the concentration of 7 phthalic acid esters (PAEs) compounds. Asaluyeh was considered as an industrial area (near gas and petrochemical industries), Bushehr as an urban area, and Goshoui as a rural area (far from pollution sources). The PAEs concentration of the street dust samples was determined using a mass detection gas chromatography (GC/MS). The mean ± SD levels of ƩPAEs in samples from industrial, urban, and rural sources were 56.9 ± 11.5, 18.3 ± 9.64, and 5.68 ± 1.85 μg/g, respectively. The mean concentration levels of ƩPAEs was significantly (P < 0.05) higher in samples from the industrial area than urban and rural areas. The mean levels of di(2-Ethylhexyl) phthalate (DEHP) in industrial, urban, and rural areas were 20.3 ± 8.76, 4.59 ± 1.71, and 2.35 ± 0.98 μg/g, respectively. The results of the PCA analysis indicate that the likely major sources of PAEs in the road dust in the studied areas are the application of various plasticizers in industry, solvents, chemical fertilizers, waste disposal, wastewater (e.g., agricultural, domestic, and industrial), and the use of plastic films and plastic-based irrigation pipes in greenhouses. As well as, it was found that the non-cancer risk of exposure to dust-bound PAEs was higher for children than for adults. These values were <1 for both age groups (children and adults) and the exposure of inhabitants to PAEs in road dust did not pose a notable non-cancer risk. The cancer risk from exposure to DEHP in road dust was below the standard range of 10-6 in all three areas. Further studies that consider different routes of exposure to these contaminants are needed for an accurate risk assessment. Moreover, since higher PAEs level was found in industrial area, decision-makers should adopt strict strategies to control the discharging of pollution from industries to the environment and human societies.

Worldwide risk assessment of phthalates and bisphenol A in humans: The need for updating guidelines

Phthalates and bisphenol A (BPA) are compounds widely used as raw materials in the production of plastics, making them ubiquitous in our daily lives. This results in widespread human exposure and human health hazards. Although efforts have been conducted to evaluate the risk of these compounds in diverse regions around the world, data scattering may mask important trends that could be useful for updating current guidelines and regulations. This study offers a comprehensive global assessment of human exposure levels to these chemicals, considering dietary and nondietary ingestion, and evaluates the associated risk. Overall, the exposure daily intake (EDI) values of phthalates and BPA reported worldwide ranged from 1.11 × 10-7 to 3 700 µg kg bw-1 d-1 and from 3.00 × 10-5 to 6.56 µg kg bw-1 d-1, respectively. Nevertheless, the dose-additive effect of phthalates has been shown to increase the EDI up to 5 100 µg kg bw-1 d-1, representing a high risk in terms of noncarcinogenic (HQ) and carcinogenic (CR) effects. The worldwide HQ values of phthalates and BPA ranged from 2.25 × 10-7 to 3.66 and from 2.74 × 10-7 to 9.72 × 10-2, respectively. Meanwhile, a significant number of studies exhibit high CR values for benzyl butyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP). Moreover, DEHP has shown the highest maximum mean CR values for humans in numerous studies, up to 179-fold higher than BBP. Despite mounting evidence of the harmful effects of these chemicals at low-dose exposure on animals and humans, most regulations have not been updated. Thus, this article emphasizes the need for updating guidelines and public policies considering compelling evidence for the adverse effects of low-dose exposure, and it cautions against the use of alternative plasticizers as substitutes for phthalates and BPA because of the significant gaps in their safety.

Co-occurrence of phthalate and non-phthalate plasticizers in dust and hand wipes: A comparison of levels across various sources

E-waste dismantlers' occupational exposure to plasticizers, particularly non-phthalate (NPAE) plasticizers, is poorly understood. This study monitored 11 phthalates (PAEs) and 16 NPAEs in dust and hand wipe samples from Central China e-waste workplace and ordinary homes. Concentrations of plasticizers in dust from e-waste dismantling workshops (median: 217 μg/g) were significantly lower than that from ordinary homes (462 μg/g; p < 0.01), however, the trend was similar but not significant in hand wipes from these two scenarios (50.2 vs. 72.3 μg/m2; p = 0.139). PAEs were still the dominant plasticizers, which is, on average, 5.46 and 3.58-fold higher than NPAEs. In all samples, di-(2ethylhexyl) phthalate (65.4%) and tri-octyl trimellitate (44.9%) were the most common PAE and NPAE plasticizers. Increasing dust concentrations of di-iso-nonyl ester 1,2-cyclohexane dicarboxylic acid, citrates and sebacates were significantly associated with their levels in worker's hand wipe, by contrast, this trend was not found in general population. Dust ingestion was the main channel, followed by hand-to-mouth contact, all participants' daily plasticizer intakes (median: 154 ng/kg bw/day) are within safety limits. Our work highlights knowledge gaps about co-exposure to PAEs and NPAEs by multiple pathways in occupational e-waste workers, which could provide baseline data in the future.

Levels and health risk assessments of Phthalate acid esters in indoor dust of some microenvironments within Ikeja and Ota, Nigeria

The levels, profiles of Phthalate acid esters (PAEs) and their associated health risk in children and adults using indoor dust samples were assessed from nine (9) microenvironments in Nigeria. Six PAEs congeners were determined using Gas Chromatography-Mass Spectrometry and the human health risk assessments of PAEs exposure to children and adults were computed using the United States Environmental Protection Agency (USEPA) exposure model. The mean concentrations of the total PAEs (Σ₆PAEs) in indoor dust across the study locations ranged from 1.61 ± 0.12 to 53.3 ± 5.27 μg/g with 72.0% of di-n-octyl phthalate (DnOP) as the most predominant contributor of PAEs in sample locations B, C, D, E, F and G. PAEs estimated daily intake results exceeded the USEPA value of 20 and 50 kg/bw/day for children and adults respectively in some locations. Non-carcinogenic risk exposure indicated no risk (HI < 1), while the carcinogenic risk was within the recommended threshold of 1.00 × 10^-4 to 1.00 × 10^-6 for benzyl butyl phthalate and bis-2-ethylhexyl phthalate. From our findings, lower levels of PAEs were observed in locations with good ventilation system. Also, the human health risk evaluation indicated indoor dust ingestion as the dominant exposure route of PAEs for both children and adults, while the children were at a higher risk of PAEs exposure. To protect children susceptible to these endocrine-disrupting pollutants, soft vinyl children's toys and teething rings should be avoided. Appropriate policies and procedures on the reduction of PAEs exposure to humans should be enacted by all stakeholders, including government regulatory agencies, industries, school administrators and the entire community.

Evaluation of levels and sources of microplastics and phthalic acid esters and their relationships in the atmosphere of highly industrialized and urbanized Gebze, Türkiye

The presence of microplastics (MPs) in the atmosphere and their relationship with other pollutants have been gaining attention due to both their ubiquity and threatening human health. As well phthalic acid esters (PAEs) regarding as plasticizers for being added in plastic materials are key role for plastic pollution. In this study, the concentrations and sources of airborne MPs together with major PAEs and their relationships were investigated for four seasons. MP particles <20 μm, constituting the majority of the samples, were successfully revealed by NR fluorescent analysis. As a result of the μATR-FTIR analyzes, it was seen that besides different polymer derivatives, dye-pigment types, some minerals and compounds, and abundant semi-synthetic fibers and natural fibers were also present. MPs concentration were found in the range of 7207-21,042 MP/m³ in summer, 7245-32,950 MP/m³ in autumn, 4035-58,270 MP/m³ in winter and 7275-37,094 MP/m³ in spring. For the same period, the concentrations of PAEs ranged from 9.24 to 115.21 ng/m³ with an average value of 38.08 ± 7.92 ng/m³. PMF was also applied and four factors were extracted. Factor 1, accounts 52.26 % and 23.27 % of the total PAEs and MPs variances, was attributed to PVC sources. Factor 2, explaining 64.98 % of the total MPs variance had the highest loading of MPs and moderate loadings of relatively low molecular weight of PAEs, was attributed to plastics and personal care products. Factor 3, explaining the 28.31 % of the total PAEs variance was laden with BBP, DnBP, DiBP and DEP and was attributed to various plastic input during the sampling campaign coming from the industrial activities. The last factor accounts for 11.65 % of the total PAEs variance and was dominated by DMEP and it was linked to a source of the activities performed in the laboratories of the university.

The effects of inhaled pollutants on reproduction in marginalized communities: a contemporary review

Important differences in health that are closely linked with social disadvantage exist within and between countries. According to the World Health Organization, life expectancy and good health continue to increase in many parts of the world, but fail to improve in other parts of the world, indicating that differences in life expectancy and health arise due to the circumstances in which people grow, live, work, and age, and the systems put in place to deal with illness. Marginalized communities experience higher rates of certain diseases and more deaths compared to the general population, indicating a profound disparity in health status. Although several factors place marginalized communities at high risk for poor health outcomes, one important factor is exposure to air pollutants. Marginalized communities and minorities are exposed to higher levels of air pollutants than the majority population. Interestingly, a link exists between air pollutant exposure and adverse reproductive outcomes, suggesting that marginalized communities may have increased reproductive disorders due to increased exposure to air pollutants compared to the general population. This review summarizes different studies showing that marginalized communities have higher exposure to air pollutants, the types of air pollutants present in our environment, and the associations between air pollution and adverse reproductive outcomes, focusing on marginalized communities.

Lipophilicity profiling and cell viability assessment of a selected panel of endocrine disruptors

Endocrine disruptors are chemicals widely used worldwide by industries in a variety of applications. Routinely exposure to these chemicals, even if at low doses, can cause damage effects on human health. In the present study, we evaluated toxic effects of nine chemicals, among which phthalates, using various cell lines to inspect their capability to interfere with cell proliferation and viability. Alongside, we investigated their affinity for phospholipids to assess the possible passage through biomembranes. Experimentally determined logk_w^IAM.MG values ranged from 1.37 to 3.49 whilst calculated log k_w^IAM.DD2 spanned from 1.80 to 5.21, supporting the target contaminants to exhibit lipophilicity moderate or very high. The achieved results were related to pharmacokinetic and toxicological properties by ADMET predictor™ and EPI Suite™ software. Triclosan and 4-Nonylphenol were found to be the most toxic against all cell lines screened, showing an IC₅₀ of 30 μM for triclosan on human keratinocytes and of 50 μM for 4-Nonylphenol on human colorectal adenocarcinoma cells. Overall, even if the phthalates showed higher IC₅₀ values (ranging from 170 μM to 280 μM), we can assert that all contaminants herein tested were able to interfere with cell growth and viability.

Associations between gastrointestinal infection and urinary phthalate metabolite concentrations in US children and adolescents from NHANES 2005-2016

The purpose of this study was to evaluate at the link between gastrointestinal illness and urine phthalate metabolite concentrations in children and adolescents in the United States between 2005 and 2016. A total of 4008 National Health and Nutrition Examination Survey (NHANES) participants had urine samples obtained during the survey and self-reported their gastrointestinal functional status over the previous week. High performance liquid chromatography/tandem mass spectrometry (HPLC/MS-MS) was used to identify twelve phthalate metabolites in urine samples. The link between PAE concentrations and gastrointestinal illnesses was investigated using logistic regression, which was controlled for possible confounders. The combined and independent effects of PAEs on gastrointestinal illnesses were investigated using Bayesian Kernel Machine Regression (BKMR) and quantile-based g-computation (qgcomp). In children and adolescents, the prevalence of gastrointestinal infection was 9.0%. One log-unit increase in urinary concentrations was associated with an increased risk of gastrointestinal infection for monocarboxyoctyl phthalate (MCOP) (adjusted odd ratio (aOR) = 1.36, 95 percent confidence interval (95%ci): 1.08, 1.62), mono(2-ethylhexyl) phthalate (MEHP) (aOR = 1.18, 95 percent CI: 1.05, 1.32) and mono(2-eth The mixed exposure model findings revealed that the combined effect of PAEs was substantially linked with gastrointestinal infection; exposure to the combination of PAEs was positively associated with the risk of gastrointestinal infection. In the BKMR model, the exposure to the mixture of PAEs was positively associated with the risk of gastrointestinal infection. In qgcomp, a substantial positive correlation between PAEs and gastrointestinal illnesses was identified (OR = 1.16, 95 percent CI: 1.05, 1.28). MCOP and MEHP may be the major contributors after controlling for other PAE homologs. These associations were more pronounced in overweight and obese children and adolescents. Mixed exposure to phthalates (PAEs) in children and adolescents was significantly associated with gastrointestinal infections, with MCOP and MEHP accounting for the major proportions. These associations were more pronounced in overweight and obese children and adolescents.

Novel control strategies for the endocrine-disrupting effect of PAEs to pregnant women in traffic system

Traffic-related air pollution has become a global issue, and scientific regulation measures are urgently needed to reduce traffic pollution. Phthalates (PAEs) have been widely detected in the traffic environment; thus, they were chosen as target pollutants because of their endocrine-disrupting effects. The pathways of action and mechanisms of PAEs' endocrine-disrupting effects in pregnant women through inhalation were deduced. A novel whole-process 1C + 3D + 5R regulation system was developed to control the endocrine-disrupting effect of PAEs on pregnant women based on the cleaning production concept. (1) For source reduction, the 2D-QSAR model of endocrine-disrupting effects of PAEs in pregnant women was constructed to screen out the key influencing factors as hydrogen bond interaction and hydrophobic interaction. Based on this, a designed PAE substitute molecule with low volatility and endocrine-disrupting effects and no developmental toxicity was screened. The substitute molecule could reduce the volatilization amount of PAEs at the source by 41.76 %; (2) For process interception, selecting C-band UV light to eliminate PAEs molecules in the traffic environment can slow down 19.99 % of the endocrine-disrupting effect of PAEs molecules. The homology modeling method was used to design four kinds of green belt plant proteins with high PAEs absorption efficiency to absorb PAEs molecules in the traffic environment. Compared with the original green belt plant proteins, the absorption amount of PAEs increased by up to 96.08 %, and (3) For terminal prevention, dietary food schemes were designed to regulate PAEs' endocrine-disrupting effect on pregnant women. The optimal dietary food scheme was the simultaneous intake of glutamate, catechin and folic acid, which could reduce the adverse effect of PAEs on maternal and infants by 32.51 %. This study presents theoretical support for regulating PAE exposure to specific populations in the traffic environment and treating other pollutants in the future.

Phthalates in dormitory dust and human urine: A study of exposure characteristics and risk assessments of university students

Phthalate diesters (PAEs) are prevalent and potentially toxic to human health. The university dormitory represents a typical and relatively uniform indoor environment. This study evaluated the concentrations of phthalate monoesters (mPAEs) in urine samples from 101 residents of university status, and the concentrations of PAEs in dust collected from 36 corresponding dormitories. Di-(2-ethylhexyl) phthalate (DEHP, median: 68.0 μg/g) was the major PAE in dust, and mono-ethyl phthalate (47.9 %) was the most abundant mPAE in urine. The levels of both PAEs in dormitory dust and mPAEs in urine were higher in females than in males, indicating higher PAE exposure in females. Differences in lifestyles (dormitory time and plastic product use frequency) may also affect human exposure to PAEs. Moreover, there were significant positive correlations between the estimated daily intakes of PAEs calculated by using concentrations of PAEs in dust (EDI_D) and mPAEs in urine (EDI_U), suggesting that PAEs in dust could be a significant source of human exposure to PAEs. The value of EDI_D/EDI_U for low molecular weight PAEs (3-6 carbon atoms in their backbone) was lower than that of high molecular weight PAEs. The contribution rate of various pathways to PAE exposure illustrated that non-dietary ingestion (87.8 %) was the major pathway of human exposure to PAEs in dust. Approximately 4.95 % of university students' hazard quotients of DEHP were >1, indicating that there may be some health risks associated with DEHP exposure among PAEs. Furthermore, it is recommended that some measures be taken to reduce the production and application of DEHP.

Characterization and quantification of endocrine disruptors in female menstrual blood samples

Selected endocrine disrupting chemicals (EDCs) were measured in adult female menstrual blood for the first time in Ghana, Africa, taking into account the importance of non-invasive means of matrices sampling in vulnerable groups, such as pregnant women, the elderly or chronically ill people. The menstrual blood samples of twenty (20) female adults between the ages of 25-45 years were sampled. The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method was applied for the extraction and clean up, while gas chromatography-mass spectrometry (GC-MS) was used to measure the selected EDCs in adult female menstrual blood, taking into account the composition of menstrual discharge. Diethyl phthalate (DEP), Dibutyl phthalate (DBP) and Bis (2-ethylhexyl) phthalate (DEHP) were detected in all samples, whereas bisphenol A (BPA) was found in 13 participants. Dimethyl phthalate (DMP) was detected in 7 participants, Di-n-octyl phthalate (DNOP) was detected in 3 participants, Bis (2-ethylhexyl) adipate (DEHA) and pyrimidine were detected in 2 participants, while benzyl butyl phthalate (BBP) was detected in only 1 participant. The maximum concentration of DEP measured was 115.6 µg.L^-1and the minimum was 439 µg.L^-1. DEHP was the next most abundant phthalate with a maximum measured concentration of 982 µg.L^-1 and minimum of 95 µg.L^-1. The presence of parent phthalates (rather than metabolites) in menstrual blood of all participants studied suggests that bioaccumulation of selected phthalate compounds such as DEHP, DEP and DBP may be occurring with appreciable human toxicity though the carcinogenic exposure risks of DEHP via various routes were much lower than 1 × 10^-6 considered to be very low.

Distribution, source apportionment and health risk assessment of phthalate esters in outdoor dust samples on Tibetan Plateau, China

The urbanization of Tibetan Plateau (TP) probably results in a significant contamination of organic pollutants in the area, such as phthalate esters (PAEs). However, there is a lack of monitoring and evaluation of their occurrence and risks in the outdoor dust on TP. This study for the first time investigated the concentrations, distributions and health risk of PAEs in outdoor dust samples on TP, China. A total of 132 outdoor dust samples were collected from five different functional areas, and results showed the ubiquitous detection of all PAEs in the samples. The Σ₆PAEs concentrations ranged from 0.08 to 31.49 μg·g^-1 with a mean of 3.57 μg·g^-1. High concentrations of Σ₆PAEs in the outdoor dust were found in commercial districts, which were attributed to the heavy use of PAEs in the public commerce such as consumer products, commodities, and building materials. Di-n-butyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were the dominant components accounting for 30.65% and 53.19% of the Σ₆PAEs. Principal component analysis, positive matrix factorization, and correlation analysis were used to apportion the potential sources of PAEs in outdoor dust samples. The PAEs in the outdoor dust originated mainly from wide application of plasticizers as well as cosmetics and personal care products. The main pathways of human exposure to PAEs in the outdoor dust were ingestion and dermal absorption of dust particles. The total intakes of PAEs from outdoor dusts for children and adults were 1.50 × 10^-5 and 2.47 × 10^-6 mg·kg^-1·d^-1, respectively. Children were more susceptible to the PAEs intake than the adults. Although the estimated health risks of the six PAEs are currently acceptable, caution is needed given the likely future increase in use of these PAEs and the currently unknown contribution to human exposure by other medium.

Cumulative human exposure and environmental occurrence of phthalate esters: A global perspective

In the current investigation, the distribution and extent of human exposure of phthalate esters (PAEs) have been reported on global extent based on computed indices. The proposed indices were calculated based on environmental concentrations, toxicity, occurrence, environmental fate, and transport of PAEs. The cumulative phthalate exposure index (PEI) based on the phthalate pollution index (PPI) was mapped on a global scale based on the existing data reported in the literature. The results revealed that the PAEs are heterogeneously distributed globally, and about 30% of total environmental PAEs are ultimately exposed to the average human being. The comparative distribution of PAEs in various environmental compartments including urban-rural, indoor-outdoor, home-dormitory-classroom, and their exposure likelihood were studied based on indices. More than 90% of total human exposure of PAEs was observed to be from indoor environmental compartments. Significantly high exposure was observed in the urban population as compared to the rural population. About 70% of the total phthalate pollution sub-index of dust was observed from home followed by a classroom of ∼15% and then a dormitory of ∼10%. In addition, the indices were equated with the current human development index (HDI), gross national income (GNI), and exposure of particulate matter of each country. Based on current findings, the population living in the areas where >20 μg/m³ of particulate matter has been reported are possibly exposed with higher PAEs. The indices were highly diversified at high HDI (0.9) values and between 40,000 and 50,000 $ per capita income due to different usage of phthalate-containing products, disposal, and extensive monitoring work carried out by the developed and developing countries.

An overview of organic contaminants in indoor dust, their health impact, geographical distribution and recent extraction/analysis methods

People spend a substantial proportion of their time indoors; therefore, exposure to contaminants in indoor dust is persistent and profuse. According to the findings of recent studies, contaminants such as flame retardants (FRs), organochlorines (OCs), and phthalate esters (PAEs) are more prevalent in indoor dust. The discrepancy in the geographical distribution of these chemicals indicates country-specific applications. However, many studies have revealed that chlorophosphates, polychlorinated biphenyls (PCBs) and di-2-ethylhexyl phthalate are frequently detected in indoor dust throughout the world. Although some chemicals (e.g., OCs) were banned/severely restricted decades ago, they have still been detected in indoor dust. These organic contaminants have shown clear evidence of carcinogenic, neurotoxic, immunogenic, and estrogenic activities. Recent extraction methods have shown their advantages, such as high recoveries, less solvent consumption, less extraction time and simplicity of use. The latest separation techniques such as two-dimensional gas/liquid chromatography, latest ionization techniques (e.g., matrix-assisted laser desorption/ionization (MALDI)), and modern techniques of mass spectrometry (e.g., tandem mass spectrometry (MS/MS), time-of-flight (TOF) and high-resolution mass spectrometry (HRMS)) improve the detection limits, accuracy, reproducibility and simultaneous detection of organic contaminants. For future perspectives, it is suggested that the importance of the study of dust morphology for comprehensive risk analysis, introducing standard reference materials to strengthen the analytical methods, adopt common guidelines for comparison of research findings and the importance of dust analysis in the developing world since lack of records on the production and usage of hazardous substances. Such measures will help to evaluate the effectiveness of prevailing legislations and to set up new regulations.

Phthalic acid esters (PAEs) in workplace and house dust from Vietnam: concentrations, profiles, emission sources, and exposure risk

The occurrence of nine phthalic acid esters (PAEs) were determined in indoor dust samples collected from vehicle repair shops, waste processing workshops, and homes in Vietnam. Concentrations of total PAEs ranged from 585 to 153,000 (median 33,400 ng/g), which fall in the lower end of global range. The PAE levels in workplace dust (median 49,100; range 9210-153,000 ng/g) were significantly higher than those in house dust (median 23,700; range 585-83,700 ng/g), indicating waste processing activities as potential PAE sources. The most predominant compound was di-(2-ethyl)hexyl phthalate (DEHP), accounting for 62 ± 18% of total PAEs. Other major compounds were benzyl butyl phthalate (BzBP) (10 ± 12%), di-n-butyl phthalate (DnBP) (9.7 ± 7.7%), di-n-octyl phthalate (DnOP) (7.9 ± 8.1%), and diisobutyl phthalate (DiBP) (6.9 ± 5.0%). Proportions of BzBP and DnBP in some workplace dust samples were markedly greater than in common house dust, suggesting specific emission sources. Daily intake doses of selected PAEs (e.g., DnBP, DiBP, BzBP, and DEHP) through dust ingestion were much lower than reference doses, implying acceptable levels of risk.

Exploring personal chemical exposures in China with wearable air pollutant monitors: A repeated-measure study in healthy older adults in Jinan, China

The health impact of airborne contaminants has been challenging to assess due to current limitations in measurement technologies. The emergence of wearable passive samplers coupled with high resolution mass spectrometry (HR-MS) chemical analysis has enabled comprehensive characterization of personal exposures. We conducted a repeated-measure study among 84 older adults in Jinan, China, as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Study objectives were: 1) to characterize the occurrence, magnitude, and distribution of personal exposure to airborne contaminants; 2) to evaluate the temporal variation of chemical exposures across the study population; and 3) to identify behavioral and environmental factors that influence the observed variance in chemical exposures. The FreshAir wristband was worn by participants for three consecutive days each month from September 2018 to January 2019 and collected with paired time-activity logs. Passive air samplers were also deployed in parallel at a local outdoor air monitoring station. Spearman's Rho trend test and trajectory cluster analysis were used to identify exposure trends and variation patterns, respectively. Out of the 70 airborne compounds of potential concern screened, 26 compounds from 10 chemical classes were found to be above detection thresholds across >70% of the study population. Personal exposures were predominantly characterized by nine polycyclic aromatic hydrocarbons (PAHs), four phthalates, three nitroaromatics, and two volatile organic compounds (VOCs). Phthalate personal exposures were positively correlated with outdoor temperatures while the inverse relationship was observed for certain PAHs (p < 0.05). Specifically, dimethyl phthalate (r_s = 0.31) decreased as temperatures declined, while nitrobenzene (r_s = -0.35) and naphthalene (r_s = -0.40) increased as temperatures decreased. Compared to levels measured at the outdoor air monitoring site, personal exposure of phthalates was elevated (p < 0.05) and hexachlorobutadiene was lower across participants (p < 0.01). Personal exposure of these chemicals was further found to be weakly associated with daily duration participants spent outdoors. Individuals formed distinct clusters based on trajectories of chemical exposures across the sampling period (September to January), potentially suggestive of distinct emission sources. In conclusion, we demonstrate the feasibility of characterizing the occurrence and magnitude of personal exposure to airborne chemical contaminants using passive wristband samplers. The temporal variability of these personal exposure profiles was highlighted and with distinct trends identified across different groups of individuals. Future studies will integrate this data with other omics datasets collected from this population of Chinese older adults to investigate associations between exposure profiles and health relevant biomarkers, to provide evidence in feasibility of disease prevention through environmental improvements.

Cardiorespiratory responses in healthy young adults with exposure to indoor airborne PAEs: A randomized, crossover trial of air purification

BACKGROUND

Phthalic acid esters (PAEs) are widely used as plasticizers in industrial process and consumer products. Nowadays, PAEs are ubiquitous in the environment and are reported to be associated with cardiorespiratory diseases. However, studies about the association between indoor airborne PAEs exposure and cardiorespiratory health were limited, and the potential biological mechanism remains under-recognized.

METHODS

A randomized crossover trial was conducted on 57 healthy young adults in Beijing. Repeated health measurements were performed under real and sham indoor air purification with a washout interval of at least 2 weeks. The concentration of indoor airborne PAEs were determined by gas chromatography-orbit ion trap mass spectrometry. Health indicators including blood pressure, lung function, airway inflammation, and circulating biomarkers reflecting blood coagulation and systematic oxidative stress were measured. Linear mixed-effect model was used to examine the between-treatment differences in health indicators, and three models including single-constituent, constituent-fine particulate matter (PM_2.5) joint, and single-constituent residual model were used to estimate the association between indoor airborne PAEs and health indicators.

RESULTS

The indoor airborne PAEs were reduced effectively under real air purification. The total indoor airborne di-2-ethylhexyl phthalate (DEHP), bis (4-Methyl-2-pentyl) phthalate (DMPP), diphenyl phthalate (DPP), and diethyl phthalate (DEP) were identified to be most significantly associated with the increase of blood pressure and airway inflammation, and decrease of lung function. A doubling increase in DEHP, DMPP, DPP, DEP was associated with the increase of 17.2% (95% CI: 3.9%, 32.2%), 11.7% (95% CI: 3.5%, 20.6%), 7.0% (95% CI: 2.4%, 11.8%), 6.0% (95% CI: 1.8%, 10.4%) in FeNO, respectively, in single-constituent residual model. Significant associations between specific total indoor airborne PAEs and increased levels of health biomarkers including oxidized low-density lipoprotein (ox-LDL), 8-isoprostane (8-isoPGF2α), and soluble P-selectin (sP-selectin) were observed.

CONCLUSION

Indoor airborne PAEs may cause adverse cardiorespiratory health effects in young healthy adults, and indoor air purification could ameliorate the adverse cardiorespiratory effects.

Characteristics of dust-phase phthalates in dormitory, classroom, and home and non-dietary exposure in Beijing, China

The phthalate concentrations in dust from undergraduate dormitories, classrooms, and homes in Beijing, China, were measured in April 2017. We analyzed the characteristics of phthalates in dust from three environments. In addition, we estimated the daily intake of phthalates via three pathways using Monte Carlo simulations. The detection frequency of eight phthalates in dust ranges from 74.5 to 100%. Di (2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and di-isobutyl phthalate (DiBP) are the most abundant phthalates. The median proportion of DEHP in dust is the highest, ranging from 67.1 to 72.9%. The PMF results indicated that two, four, and three types of phthalate sources exist in home, dormitory, and classroom, respectively. The differences in the phthalate concentrations between sunny and shaded rooms and urban and suburban classrooms are insignificant, whereas that between male and female dormitories is significant. The total daily intake of DEHP, DnBP, and DiBP ranges from 97.3 to 336 ng/ (kg·day). The oral intake for DEHP in classrooms and the dermal intake of DnBP and DiBP in homes are the highest. The carcinogenic risk of DEHP to university students is the highest in classrooms and the total carcinogenic risk of the three environments is 4.70 × 10^-6.

Inverse association of certain seminal phthalate metabolites with semen quality may be mediated by androgen synthesis: A cross-sectional study from the South China

BACKGROUND

Several in vitro and in vivo studies have demonstrated the effects of phthalates on androgen synthesis, and the adverse outcomes of phthalate exposure on male reproductive function have been reported. However, the direct relationship among these three factors remains unknown.

OBJECTIVE

To explore the potential roles of steroids involved in androgen synthesis in the association between phthalate exposure and semen quality.

METHODS

Eighteen phthalate metabolites (mPAEs) and nine steroids were analyzed in semen samples of 403 male participants aged 18-54 years from a hospital in Shenzhen, China. The associations across phthalate metabolites, steroids, and eleven semen quality parameters were evaluated by multivariate linear regression and logistical regression models. The potential contributions of steroids to the associations between phthalate metabolites and semen quality outcomes were explored by mediation effect analysis.

RESULTS

In this cross-sectional study, mono-n-butyl phthalate (MnBP) was inversely associated with nine continuous semen quality parameters in a dose-dependent manner (all p for trend < 0.05). Positive associations were observed between MnBP tertiles and androstenedione (ADD) and pregnenolone (PGL), of which only ADD was significantly associated with sperm quality (i.e., motility, p < 0.05). The estimated average mediated effects of seminal ADD on the associations between MnBP and lower sperm motility parameters (i.e., total motility, TR; progressive motility, PR; curvi-linear velocity, VCL) were 6.4-11.9% (all p < 0.05). The potential mediated effects of ADD on the increasing risks of TR (9.8%) and PR (8.5%) abnormalities induced by MnBP exposure were also observed in logistical regression analysis.

CONCLUSION

Our results indicated that androgen synthesis in reproductive system may be potentially affected by phthalate exposure, thereby resulting in reduced sperm motility in adult men. Further studies are needed to understand the actual roles and underlying mechanism of action of androstenedione on these associations.

Fe-Mn oxide modified biochar decreases phthalate uptake and improves grain quality of wheat grown in phthalate-contaminated fluvo-aquic soil

We used a pot experiment to investigate the effectiveness of 0.5, 1.0, and 2.0% biochar (BC) or iron-manganese oxide modified biochar (FMBC) additions on the biomass, enzyme activity, and grain quality of wheat plants grown in dibutyl phthalate (DBP) and di-(2-ethylhcxyl) phthalate (DEHP) polluted fluvo-aquic soils, as well as the bioavailability of DBP and DEHP. BC and FMBC applications significantly reduced DBP and DEHP accumulation in grains, which enhanced the content of starch and protein-related enzyme, thereby improving yield, and starch and protein content in wheat grains and increasing the content of minerals including Fe, Mn, K and Ca. Molecular docking assays showed that DBP and DEHP could bind to starch synthase (GBSS) through hydrogen bonds and intermolecular forces, which may have hindered the entry of substrates or occupied the binding sites of the reactants, thus inhibiting the activity of GBSS. In addition, FMBC treatment had a better inhibitory effect on the phytotoxicity of DBP and DEHP on wheat grain than BC treatment. This result might be attributed to the fact that FMBC has more functional groups and porous structure, and larger specific surface area. In summary, these findings contribute to our understanding of the mechanism of phthalate phytotoxicity, which may help us prevent/reduce it in the future.