Occurrence and human health risks of phthalates in indoor air of laboratories

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.

Concentrations of potentially endocrine disrupting chemicals in car cabin air and dust - Effect of temperature and ventilation

Materials in car cabins contain performance-enhancing semi-volatile organic compounds (SVOCs). As these SVOCs are not chemically bound to the materials, they can emit from the materials at slow rates to the surrounding, causing human exposure. This study aimed at increasing the understanding on abundance of SVOCs in car cabins by studying 18 potential endocrine disrupting chemicals in car cabin air (gas phase and airborne particles) and dust. We also studied how levels of these chemicals varied by temperature inside the car cabin along with ventilation settings, relevant to human exposure. A positive correlation was observed between temperature and SVOC concentration in both the gas and the particle phase, where average gas phase levels at 80 °C were a factor of 18-16,000 higher than average levels at 25 °C, while average particle phase levels were a factor of 4.6-40,000 higher for the studied substances. This study also showed that levels were below the limit of detection for several SVOCs during realistic driving conditions, i.e., with the ventilation activated. To limit human exposure to SVOCs in car cabins, it is recommended to ventilate a warm car before entering and have the ventilation on during driving, as both temperature and ventilation have a significant impact on SVOC levels.

Pollution characteristics, sources, and health risks of phthalate esters in ambient air: A daily continuous monitoring study in the central Chinese city of Nanchang

In recent years, the atmospheric pollution caused by phthalate esters (PAEs) has been increasing due to the widespread use of PAE-containing materials. Existing research on atmospheric PAEs lacks long-term continuous observation and samples from cities in central China. To investigate the pollution characteristics, sources, and health risks of PAEs in the ambient air of a typical city in central China, daily PM2.5 samples were collected in Nanchang from November 2020 to October 2021. In this study, the detection and quantification of six significant PAE contaminants, namely diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), Di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DnOP), and diisodecyl phthalate (DIDP), were accomplished using gas chromatography and mass spectrometry. The results revealed that the concentrations of DEP, DnBP, DEHP, and DnOP were relatively high. Higher temperatures promote the volatilization of PAEs, leading to an increase in the gaseous and particulate PAE concentrations in warm seasons and winter pollution scenarios. The results of principal component analysis show that PAEs mainly come from volatile products and polyvinylchloride plastics. Using positive matrix factorization analysis, it is shown that these two sources contribute 67.0% and 33.0% in atmosphere PAEs, respectively. Seasonally, the contribution of volatile products to both gaseous and particulate PAEs substantially increases during warm seasons. The residents in Nanchang exposed to PAEs have a negligible non-cancer risk and a potential low cancer risk. During the warm seasons, more PAEs are emitted into the air, which will increase the toxicity of PAEs and their impact on human health.

Atmospheric phthalate esters in a multi-function area of Hangzhou: Temporal variation, gas/particle phase distribution, and population exposure risk

Phthalate esters (PAEs) are prevalent in both indoor and outdoor environments. However, there are relatively few studies on phthalate contamination in the air of multi-function areas. Experiments were conducted to analyze the concentrations of 14 distinct PAEs in outdoor air in the college town of Hangzhou throughout both the warm and cold seasons. Correlation and principal component analyses were performed to investigate the influence and source factors of PAEs. This study also focused on the relationship between the gas/particle partition coefficient Kp and temperature, as well as the application of the gas/particle partition model. The risk of exposure to PAEs via inhalation was predicted for four groups of the general population: toddlers, adolescents, adults, and older adults. The results indicated that the concentration levels of Σ14PAEs in outdoor air were 1573 ng/m3 in the gaseous phase and 126 ng/m3 in the particulate phase. Additionally, this study indicated three primary sources of PAEs: indoor diffuse sources, industrial emission sources, and building construction sources. The gas/particle partitioning of PAEs also revealed that low-molecular-weight PAEs are more prevalent in gas, whereas high-molecular-weight PAEs are more predominant in the particle phase. A health risk analysis revealed high estimations of daily intakes (EDI) for toddlers and adolescents and high lifetime average daily doses (LADD) for older adults. This study establishes a solid foundation for formulating scientific and effective air pollution control measures by analyzing the characteristics and assessing the health risks of PAEs.

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.

Enhanced migration of plasticizers from polyvinyl chloride consumer products through artificial sebum

In the present study, the migration of plasticizers from modeled and commercial polyvinyl chloride (mPVC and cPVC, respectively) to poly(dimethylsiloxane) via artificial sebum was assessed to mimic the dermal migration of plasticizers. In addition, the various factors affecting migration of phthalic acid esters (PAEs) from diverse PVC products were investigated. The migrated mass and migration ratio of PAEs increased but the migration rate decreased over time. The migration rate increased with sebum mass, contact time, and temperature but decreased under higher pressure. Low-molecular-weight PAEs (dimethyl phthalate and diethyl phthalate) migrated in higher amounts than high-molecular-weight PAEs (dicyclohexyl phthalate [DCHP] and diisononyl phthalate [DINP]). Diffusion of all PAEs in mPVC increased with temperature, with diffusion coefficients ranging from 10^-13 to 10^-15, 10^-12 to 10^-14, and 10^-10 to 10^-12 cm²·s^-1 at 25 °C, 40 °C, and 60 °C, respectively; the enthalpy of activation ranged between 127 and 194 kJ·mol^-1. Moreover, migration depended on total PAE content of the product, as the diffusion coefficient for DINP in cPVC (softer PVC) was approximately three orders of magnitude higher than that for DINP in mPVC (harder PVC); this may be due to the increase in free volume with increasing plasticizer content. Finally, the daily exposure doses of the plasticizers were estimated. These findings will be helpful for estimating dermal exposure risk.

Seasonal variations of airborne phthalates and novel non-phthalate plasticizers in a test residence in cold regions: Effects of temperature, humidity, total suspended particulate matter, and sources

As a class of plasticizers widely used in consumer products, some phthalate esters (PAEs) have been restricted due to their adverse health effects and ubiquitous presence, leading to the introduction of alternative non-phthalates plasticizers (NPPs) to the market. However, few studies focus on the influence of environmental parameters on the presence of these plasticizers and the potential human health risks for people living in poorly ventilated indoor spaces in cold regions. We investigated the trends of PAEs and NPPs in air in a typical indoor residence in northern China for over one year. The air concentrations of PAEs were significantly higher than those of NPPs (p < 0.05), indicating that PAEs are still the dominant plasticizers currently being used in the studied residence. PAEs showed seasonal fluctuation patterns of the highest levels found in summer and autumn. The temperature and relative humidity dependence for most PAEs and NPPs decreased with decreasing vapor pressure. Concentrations of the high molecular weight NPPs and PAEs positively correlated with total suspended particles (TSP). It is worth noting that the peak concentrations of PAEs and NPPs were found when the haze occurred in autumn. Principal component analysis (PCA) suggested the diverse applications of PAEs and NPPs in the indoor environment. The hazard index (HI) values observed in this study were all below international guidelines (<1); however, the average carcinogenic risk (CR) values for some compounds exceeded acceptable levels (One in a million), which raised concerns about the possibility of carcinogenicity for people living indoors for long periods of time in cold regions.

Phthalates in glass window films are associated with dormitory characteristics, occupancy activities and habits, and environmental factors

Phthalates are environmental endocrine disruptors that enter the human body through a variety of pathways and harm human health. The study aimed to explore the associations between phthalate concentrations in glass window films with dormitory characteristics, occupancy activities and habits, and environmental factors, of university dormitories. We surveyed these associations and measured the indoor environmental parameters of 144 dormitories from 13 universities in Beijing. Based on the results, we further explored the factors affecting phthalate concentrations using multivariate logistic regression. The results showed that phthalate concentrations in glass window films were associated with dormitory type, duration of occupancy, daily ventilation duration, window cleaning frequency, indoor relative humidity, light intensity, temperature, and particulate matter (PM₁₀) concentration. To date, there have only been a few studies on the factors that influence phthalate concentrations in glass window films; therefore, further study is needed. Our findings determined the influence of external factors on the different types of phthalates in window films, which helps understand indoor phthalate pollution and evaluate human exposure based on phthalate concentrations in glass window films.

Phthalic acid esters in grains, vegetables, and fruits: concentration, distribution, composition, bio-accessibility, and dietary exposure

Grain, vegetable, and fruit samples were collected from Xi'an City in Northwest China and analyzed for the characteristics, bio-accessibility, and dietary exposure of 22 phthalic acid esters (PAEs). All the studied PAEs were ubiquitously detected, except for diethyl phthalate in vegetables and fruits. In grains, the sum of detectable PAEs (∑22PAEs) varied between 0.0840 and 40.0 µg/g, with a mean of 4.19 µg/g, presenting rice >  > beans > flour, and the major PAEs were di-n-butyl phthalate (DnBP) and bis(2-ethylhexyl) phthalate (DEHP). In vegetables, the ∑21PAEs ranged from 0.190 to 56.8 µg/g, with a mean of 8.07 µg/g, exhibiting leafy vegetables > root vegetables > fruits-vegetables > fungus > cauliflower > beans, and the main PAEs were di-iso-butyl phthalate (DiBP), DnBP, DEHP, di-iso-nonyl phthalate (DiNP), and di-iso-decyl phthalate (DiDP). In fruits, the ∑21PAEs varied between 0.300 and 12.6 µg/g, with a mean of 3.97 µg/g, presenting spring-winter season fruits > summer-autumn season fruits and shell-less fruits > shelled fruits, and the predominant PAEs were DiBP, DnBP, DEHP, DiNP, and DiDP. The bio-accessibility of PAEs in the gastrointestinal fluid simulant was higher than that in the single gastric or intestinal fluid simulant. The bio-accessibility of PAEs was correlated with the physiochemical properties of PAEs. The estimated daily intakes (EDIs) of human dietary exposure to PAEs were lower than the reference doses of United States Environmental Protection Agency and the tolerable dairy intakes (TDIs) of European Food Safety Authority (EFSA), except for the EDI of DnBP in the grains and DiBP in the vegetables higher than or close to the TDI of the EFSA. The research suggested that special attention should be paid to human dietary exposure to DnBP and DiBP, especially for children and adolescents.

Gas-phase and PM2.5-bound phthalates in nail salons: characteristics, exposure via inhalation, and influencing factors

This study aimed to investigate the characteristics of, exposure to, and factors influencing gas-phase and PM_2.5-bound phthalates (PAEs) in nail salons. Data on both indoor and outdoor gas-phase and PM_2.5-bound PAEs, carbon dioxide (CO₂), temperature, and relative humidity were collected in nail salons. We also used questionnaires to survey building characteristics and occupants' behaviors. The average total gas-phase and PM_2.5-bound PAE concentrations indoors were higher than those outdoors by 6 and 3 times, respectively. Diethyl phthalate, diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di-(2-ethylhexyl) phthalate (DEHP) were the predominant compounds among both the gas-phase and PM_2.5-bound PAEs in indoor air. The volume of the salon's space or the difference of indoor and outdoor CO₂ concentrations (dCO₂) was significantly associated with indoor PAE concentrations. The ratios of PM_2.5-bound to gas-phase PAEs, especially high-molecular-weight PAEs, were positively associated with the dCO₂ concentrations. Higher ratios of indoor to outdoor PM_2.5-bound DiBP, DnBP, and DEHP concentrations were discovered when more clients visited each day. Building characteristics, ventilation conditions, and occupants' activities have influences on the gas-phase and particle-phase PAEs. The study identifies the characteristics of gas-phase and PM_2.5-bound PAEs in nail salons and their influencing factors.

Health risks of phthalates: A review of immunotoxicity

Phthalates (PAEs) are known environmental endocrine disruptors that have been widely detected in several environments, and many studies have reported the immunotoxic effects of these compounds. Here, we reviewed relevant published studies, summarized the occurrence and major metabolic pathways of six typical PAEs (DMP, DEP, DBP, BBP, DEHP, and DOP) in water, soil, and the atmosphere, degradation and metabolic pathways under aerobic and anaerobic conditions, and explored the molecular mechanisms of the toxic effects of eleven PAEs (DEHP, DPP, DPrP, DHP, DEP, DBP, MBP, MBzP, BBP, DiNP, and DMP) on the immune system of different organisms at the gene, protein, and cellular levels. A comprehensive understanding of the mechanisms by which PAEs affect immune system function through regulation of immune gene expression and enzymes, increased ROS, immune signaling pathways, specific and non-specific immunosuppression, and interference with the complement system. By summarizing the effects of these compounds on typical model organisms, this review provides insights into the mechanisms by which PAEs affect the immune system, thus supplementing human immune experiments. Finally, we discuss the future direction of PAEs immunotoxicity research, thus providing a framework for the analysis of other environmental pollutants, as well as a basis for PAEs management and safe use.

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.

Uptake pathways of phthalates (PAEs) into Chinese flowering cabbage grown in plastic greenhouses and lowering PAE accumulation by spraying PAE-degrading bacterial strain

Uptake pathway and accumulation variation of soil and airborne phthalates (PAEs) in plastic greenhouses by vegetables remains unclear. Here, pot experiments of Chinese flowering cabbage were designed to distinguish root or leaf uptake pathways of PAEs, and investigate the mitigation of spraying PAE-degrading strain in PAE accumulation by vegetables. The results showed that leaves of Chinese flowering cabbage grown in plastic greenhouses absorbed more PAEs from air than those of outside greenhouses. Airborne PAEs were mainly stored in leaf surfaces of vegetables grown inside greenhouse, while PAEs absorbed by roots from soil were translocated and mainly stored in mesophyll, especially in cell walls and organelles. PAE concentrations in mesophyll elevated with increasing soil PAE levels, whereas those in leaf surfaces were not influenced by soil PAE levels. The values of bioconcentration factors for leaves inside greenhouses were significantly (1.39-3.47 fold) higher than those outside. PAE-degrading strain (Rhodococcus pyridinivorans XB) sprayed on leaf surfaces could grow well and Rhodococcus was the dominant genus as confirmed by Illumina high-throughput sequencing. PAE-degrading strain effectively reduced PAEs by 12.9%-34.9% in leaf surface, but not those in vegetables grown in high-PAE soil. This study demonstrated mitigation of spraying PAE-degrading strain in PAE accumulation by vegetable leaves from air of plastic greenhouse.

Phthalates in skin wipes: Distribution, sources, and exposure via dermal absorption

Phthalates, which are widely used in industrial products, can be dermally absorbed into the human body and harm human health. In this study, we measured the levels of phthalates in skin wipes collected from 30 undergraduate volunteers. The body surfaces wiped include the forehead, forearms, hands, back, calves, and insteps. We analyzed the characteristics and possible sources of phthalates on the skin surface and used Monte Carlo simulations to estimate dermal exposure. The mean total dermal exposure was in the range of 0.129-8.25 μg/(kg·day). Seven phthalates were detected, with a detection frequency of 57-100%. Phthalate levels were not significantly different between symmetrical locations, but differed significantly at the same sampling location. The mean dinonyl phthalate (DNP) contribution was the highest on the forehead, back, and forearm. The mean DNP and di (2-n-butoxyethyl) phthalate (DBEP) contributions on hands were the highest and second-highest, respectively. The mean DBEP contribution was the highest on calf and instep. Phthalates level was the maximum on the forehead and instep. Habit and activities can lead to significant differences in phthalate concentrations on the skin surfaces of male and female students. The sum of dermal exposure on the torso, head, and feet perhaps best approximates the total body exposure. To date, information on the dermal exposure and related species of phthalates are limited; therefore, further study is needed.

Tissue distribution of phthalates in celery under different cultivation patterns and associated dietary exposure

To investigate tissue distribution, spatial difference, temperature variation, and potential health risks of PAEs in vegetables, celery was used as a model plant. Celery samples were collected from open fields and greenhouses from two provinces in China over four seasons. Celery tissues were analyzed for 16 PAE compounds by gas chromatography-tandem mass spectrometry. The total content of PAEs was 89.0-1130.3 μg kg^-1 dry weight (dw) in stems and 155.0-2730.8 μg kg^-1 dw in leaves. Concentrations of PAEs in celeries showed notable spatial differences (P < 0.05), and the levels in samples from open fields were lower than those in samples from plastic greenhouses. In celeries from greenhouses, higher PAE concentrations were observed for plants grown at high temperatures than in plants grown at low temperatures. Discrepancies in tissue distribution indicated different uptake pathways of PAE contaminants. Risk assessments to humans found that both carcinogenic risks and non-carcinogenic risks of PAEs via celery consumption were at an acceptable level. Further research should consider other exposure pathways of PAEs and pay special attention to reducing PAE contents in vegetables.

Inhibition of Human Sulfotransferases by Phthalate Monoesters

OBJECTIVE

This study aimed to investigate the inhibition of human important phase II metabolic enzyme sulfotransferases (SULTs) by phthalate monoesters, which are important metabolites of phthalate esters (PAEs).

METHOD

Recombinant SULT-catalyzed metabolism of p-nitrophenol (PNP) was employed as the probe reactions of SULTs to investigate the inhibition of 8 kinds of phthalate monoesters towards SULT isoforms. An in vitro incubation system was utilized for preliminary screening, and 100 μM of phthalate monoesters was used. Inhibition kinetics were carried out to determine the inhibition of SULTs by phthalate monoesters.

RESULT

Multiple phthalate monoesters have been demonstrated to exert strong inhibition potential towards SULT1A1, SULT1B1, and SULT1E1, and no significant inhibition of phthalate monoesters towards SULT1A3 was found. The activity of SULT1A1 was strongly inhibited by mono-hexyl phthalate (MHP), mono-octyl phthalate (MOP), mono-benzyl phthalate (MBZP), and mono-ethylhexyl phthalate (MEHP). Monobutyl phthalate (MBP), MHP, MOP, mono-cyclohexyl phthalate (MCHP), and MEHP significantly inhibited the activity of SULT1B1. MHP, MOP, and MEHP significantly inhibited the activity of SULT1E1. MOP was chosen as the representative phthalate monoester to determine the inhibition kinetic parameters (K_i) towards SULT1B1 and SULT1E1. The inhibition kinetic parameters (K_i) were calculated to be 2.23 μM for MOP-SULT1B1 and 5.54 μM for MOP-SULT1E1. In silico docking method was utilized to understand the inhibition mechanism of SULT1B1 by phthalate monoesters.

CONCLUSIONS

All these information will be beneficial for understanding the risk of phthalate monoester exposure from a new perspective.

A Novel Personal Passive Sampler for Collecting Gaseous Phthalates

Dermal absorption of gaseous chemicals is an important contributor to increased health risk and has yet to be adequately addressed due to the lack of available sampling techniques. In the present study, a novel personal passive sampler consisting of a housing (embracing a polydimethylsiloxane (PDMS) disk as the sorbent phase, a membrane filter, and a stainless-steel mesh) and a watchband (traditional wristband) was constructed and used to characterize gaseous phthalates (PAEs) near the air-skin interface. In a real-life setting, the utility of the passive sampler was validated by comparing the composition profiles of PAEs in the PDMS disks and in active samples and watchbands. The compositions of PAEs were consistent in disks and gaseous constituents from ambient air, with low-molecular-weight (<306 g mol^-1) PAEs accounting for 87-100% and approximately 100%, respectively. Appreciable amounts of diisononyl phthalate, diisodecyl phthalate, dinonyl phthalate, and skin lipid (e.g., squalene) were detected in watchbands but not in disks. Apparently, the passive sampler can prevent particles and skin-related chemicals from adhering to the disk and collect gaseous PAEs only. The vast majority of PAEs in watchbands was associated with nongaseous constituents. The present study demonstrated that the sampling strategy is a key factor in exposure assessment.

Development of an in vitro model to simulate migration of organic contaminants from pad products to human sweat and enhance dermal exposure risk assessment

Dermal sorption is an important route for human exposure to organic chemicals embedded in consumer products, but the related chemical migration from consumer products to sweats was often overlooked in assessing skin exposure risk. To address this issue, the present study selected polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), and benzothiazoles (BTs) as the target compounds and developed an in vitro simulation model with two artificial sweats (i.e., acidic and alkaline), a sorbent, and a PVC standard material. An appropriate biological inhibitor (ampicillin) and incubation time of 20 d for assessing the maximum migration efficiency of chemicals were selected. The mass balance of the target compounds during the in vitro incubation was verified. The established in vitro simulation model was used to determine the migration ratios of PAEs and BTs in three types of mouse pads. The maximum migration ratios of DBP, DIBP, DEHP, and BT from leather pad to both sweats were less than those for silicone and rubber pads. Key controlling parameters in migration ratios should be examined in subsequent investigations. Risk assessment showed that the daily exposure doses of PAEs and BTs in mouse pads were higher than the literature data. The hazard index of PAEs in leather pad exceed 1, indicating that PAEs could induce non-carcinogenic effects to human health through hand contact. Overall, the established in vitro simulation model provides a feasible alternative for assessing the potential risk for dermal exposure to consumer products.

Production, Use, and Fate of Phthalic Acid Esters for Polyvinyl Chloride Products in China

Phthalic acid esters (PAEs) are the most common plasticizers, approximately 90% of which are used in polyvinyl chloride (PVC) products, but they are also endocrine disruptors that have attracted considerable attention. The metabolism of PAEs in PVC products in China from 1958 to 2019 was studied using dynamic material flow analysis. The results showed that the total consumption of PAEs was 29.2 Mt in the past 60 years. By 2019, the in-use stocks of PAEs were 5.0 Mt. Construction materials were always in the leading position with respect to the consumption and in-use stocks of PAEs. A total PAE loss of 22.7 Mt was generated, of which 68.0% remained in waste distributed in landfills (50.1%), storage sites (5.5%), the environment (44.4%), 12.4% was eliminated during waste incineration and open burning, and 19.6% was emitted into the environment. From 1958 to 2019, 496.4, 55.6, and 3905.0 kt of PAEs were emitted into water, air, and soil, respectively. The use and waste treatment stages contributed 79.3 and 19.9% of the emissions of PAEs in the life cycle, respectively. This study systematically analyzed the metabolism of PAEs at the national level over a long-time span, providing useful information on the life cycle management of PAEs.

Levels of Phthalates, Bisphenol-A, Nonylphenol, and Microplastics in Fish in the Estuaries of Northern Taiwan and the Impact on Human Health

Due to the sparsity in knowledge, we investigated the presence of various estrogenic endocrine-disrupting chemicals (EEDCs), including phthalates (PAEs), bisphenol-A (BPA), and nonylphenol (NP), as well as microplastics (MPs) in samples of the most widely consumed fish collected from different estuaries in northern Taiwan. We then proceeded to determine the likely contribution that this exposure has on the potential for health impacts in humans following consumption of the fish. Six hundred fish caught from five river estuaries (producing 130 pooled samples) were analyzed to determine how different factors (such as the river, benthic, pelagic, and migratory species) influence EEDCs’ contamination and the possible impacts on human health following typical consumption patterns. The predominant EEDCs was diethyl phthalates (DEP), bis (2-ethylhexyl) phthalates (DEHP), and di-iso-nonylphthalate (DINP) in fish, present at 52.9 ± 77.3, 45.3 ± 79.8, and 42.5 ± 79.3 ng/g dry weight (d.w.), respectively. Residual levels of NP, BPA, and MPs in the fish were 17.4 ± 29.1 and 1.50 ± 2.20 ng/g d.w. and 0.185 ± 0.338 mg/g d.w., respectively. EEDCs and MPs levels varied widely among the five river estuaries sampled due, in part, to differences in habitat types and the associated diversity of fish species sampled. For DEP, the Lao-Jie River and pelagic environments produced the most severely contaminated fish species, respectively. DEP residues were also associated with the burden of MPs in the fish. Based on our analysis, we predict no substantial direct human health risk by EEDCs based on typical consumption rates of estuarine fish by the Taiwanese people. However, other sources of EEDC exposure cannot be ignored.

Lycopene prevents DEHP-induced hepatic oxidative stress damage by crosstalk between AHR-Nrf2 pathway

Di (2-ethylhexyl) phthalate (DEHP) is a widespread plasticizer that persists in the environment and can significantly contribute to serious health hazards of liver especially oxidative stress injury. Lycopene (LYC) as a carotenoid has recently gained widespread attention because of antioxidant activity. However, the potential mechanism of DEHP-induced hepatotoxicity and antagonism effect of LYC on it are still unclear. To explore the underlying mechanisms of this hypothesis, the mice were given by gavage with LYC (5 mg/kg) and DEHP (500 or 1000 mg/kg). The data suggested that DEHP caused liver enlargement, reduction of antioxidant activity markers, increase of oxidative stress indicators and disorder of cytochrome P450 enzymes system (CYP450s) homeostasis. DEHP-induced reactive oxygen species (ROS) activated the NF-E2-relatedfactor2 (Nrf2) and nuclear xenobiotic receptors (NXRs) system including Aryl hydrocarbon receptor (AHR), Pregnane X receptor (PXR) and Constitutive androstane receptor (CAR). Interestingly, these disorders and injuries were prevented after LYC treatment. Taken together, DEHP administration resulted in hepatotoxicity including oxidative stress injury and disordered CYP450 system, but these alterations might be ameliorated by LYC via crosstalk between AHR-Nrf2 pathway.

Contamination and human health risks of phthalate esters in vegetable and crop soils from the Huang-Huai-Hai region of China

The widespread presence of phthalate esters (PAEs) in a variety of agricultural inputs has led to PAE contamination in soils and farm products. The endocrine disruption and carcinogenicity of PAEs have attracted much attention. Our research investigated the characteristics of PAE pollution in the soils of vegetable fields and adjacent stable crop fields in four provinces/municipalities across a major agricultural production area in China. We found that the concentrations of PAEs in vegetable soils were not significantly higher than those in stable crop soils. The noncarcinogenic and carcinogenic risks from bis (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) to humans were calculated to represent the risk posed by PAEs. The results showed that diet was the main route for noncarcinogenic risks from PAEs in crop soil and vegetable soils. Because of the combined effect of the population dietary structure and the concentration of PAEs in soils, the noncarcinogenic risks from PAEs in crop soils were similar to or higher than those in vegetable soils. The same pattern was also applicable to the carcinogenic risk from DEHP. Low noncarcinogenic and carcinogenic risks posed by DEHP and DBP indicated that the current level of PAEs in soils did not decrease the safety of agricultural products in the Huang-Huai-Hai region. Stable crop soil, as a non-negligibly phthalate-polluted area, is worthy of as much attention as vegetable soil. This study provides scientific support for food safety risk assessment and control of PAE pollution in the main agricultural production areas in China.

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.

Remediation strategies for mitigation of phthalate pollution: Challenges and future perspectives

Phthalates are a group of emerging xenobiotic compounds commonly used as plasticizers. In recent times, there has been an increasing concern over the risk of phthalate exposure leading to adverse effects to human health and the environment. Therefore, it is necessary to not only understand the current status of phthalate pollution, their sources, exposure routes and health impacts, but also identify remediation technologies for mitigating phthalate pollution. Present review article aims to inform its readers about the ever increasing data on health burdens posed by phthalates and simultaneously highlights the recent advancements in research to alleviate phthalate contamination from environment. The article enumerates the major phthalates in use today, traces their environmental fate, addresses their growing health hazard concerns and largely focus on to provide an in-depth understanding of the different physical, chemical and biological treatment methods currently being used or under research for alleviating the risk of phthalate pollution, their challenges and the future research perspectives.

Risk Assessment of Agricultural Plastic Films Based on Release Kinetics of Phthalate Acid Esters

Plastic films have become an integral part of fruit and vegetable production systems, but their release of phthalate acid esters (PAEs) is a threat to human health. The release kinetics of PAEs and measures of risk are still not well understood. We investigated 50 agricultural films, with concentrations ranging from 2.59 to 282,000 mg kg^-1. The seven commercially available film types included were polyvinylchloride (PVC), metallocene polyethylene (mPE), ethylene vinyl acetate (EVA), polyolefin (PO), and three mulch films. Bis(2-ethylhexyl) phthalate (DEHP) was detected in most of films, and its release fitted well into the first-order kinetic model. The release rate of DEHP was negatively related to the film thickness. The potential carcinogenic risks of DEHP in the air of six kinds of plastic greenhouses to human health were estimated. We found that the carcinogenic risks associated with PVC and mPE greenhouse films warrant greater attention. Though EVA, PO greenhouse, and mulch films were lower risk, we advise keeping plastic greenhouses well ventilated during the first month of use to reduce direct human exposure to volatile PAEs.

Miniaturized active air sampling method for the analysis of tire rubber pollutants from indoor and outdoor places

An effective, quick, and sustainable air analysis method was developed to analyze 41 volatiles and semivolatile organic compounds present in tire rubber and crumb rubber materials. The proposed method, based on active sampling using a sorbent material followed by an ultrasound assisted extraction, was developed with the aim of obtaining a fast and simple procedure to determine polycyclic aromatic hydrocarbons, plasticizers, antioxidants, and vulcanization agents in air. A small amount of sorbent (25 mg) was used, and the analytes were recovered in only 1 mL of solvent. An experimental design was applied to study the influence of main factors such as type of sorbent and type of solvent, extraction technique (ultrasound-assisted extraction and vortex extraction), extraction time, as well as the factor interactions. Under optimal conditions, no breakthrough occurs in the studied interval (up to 4 m³ ). Linearity was demonstrated in a wide concentration range. Accuracy of the total sampling-extraction analysis was evaluated obtaining satisfactory recoveries as well as good precision. The method was successfully applied to different outdoor and indoor air environments, including a recycled rubber synthetic turf football pitch.

Occurrence, removal, and environmental risk of phthalates in wastewaters, landfill leachates, and groundwater in Poland

Phthalates or phthalic acid esters (PAEs) are chemical compounds whose use is exceptionally widespread in everyday materials but, at the same time, have been proven to have harmful effects on living organisms. Effluents from municipal wastewater treatment plants (WWTP) and leachates from municipal solid waste (MSW) landfills are important sources of phthalates with respect to naturally occurring waters. The main aim of this research was determination, mass loads, removal rates and ecological risk assessment of eight phthalates in municipal wastewaters, landfill leachates and groundwater from Polish WWTPs and MSW landfills. Solid-phase microextraction and gas chromatography with mass spectrometry were used for the extraction and determination of analytes. Summed up concentrations of eight phthalates ranged from below LOD to 596 μg/L in influent wastewater with the highest concentration found for bis-2-ethylhexyl phthalate (DEHP) (143 μg/L). The average degree of phthalate removal varies depending on the capacity of a given treatment plant with larger treatment plants coping better than smaller ones. The highest treatment efficiency for all tested treatment plants, over 90%, was reported for dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall concentrations of phthalates in leachates ranged from below LOD to 303 μg/L while the highest maximum concentration was registered for DEHP (249 μg/L). Overall concentrations of phthalic acid esters in groundwater from upstream monitoring wells ranged from below LOD to 1.8 μg/L and from LOD to 27.9 μg/L in samples from wells downstream of MSW landfills. The obtained data shows that diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), DEHP, and diisononyl phthalate (DINP) pose a high risk for all trophic levels being considered in effluent wastewaters. In the case of groundwater high environmental risk was recorded for DBP and DEHP for all tested trophic levels. Phthalates, in concentrations that pose a high environmental risk, are present in Polish municipal after-treatment wastewater as well as in groundwater under municipal solid waste landfills.

Prevalent phthalates in air-soil-vegetable systems of plastic greenhouses in a subtropical city and health risk assessments

Wide use of plastic greenhouses for vegetable production increases human exposure to phthalate (PAEs) through vegetable intake. However, little information is available about distribution of PAEs in air-soil-vegetable systems of plastic greenhouses and PAE estrogenic effects. This study was designed to investigate PAE distributions and corresponding health risk in plastic greenhouses in Guangzhou, a subtropical city in South China. PAEs were prevalent in plastic greenhouses, with sum concentrations of 16 PAE compounds (∑16PAEs) up to 5.76 mg/kg in soils, 5.27 mg/kg in vegetables and 4393 ng/m³ in air. Di (2-ethylhexyl) phthalate, di-isobutyl phthalate, and dibutyl phthalate were predominant compounds. Average concentrations and bioconcentration factor of ∑16PAEs and the predominant PAE compounds in vegetables of greenhouses were higher than those of open fields. Plastic greenhouses exhibited significantly higher air PAE levels than those of open fields due to higher indoor temperature, which enhanced PAE accumulation by vegetables. Both carcinogenic and non-carcinogenic risks of PAEs via dietary and non-dietary exposures for farmers decreased with an order of vegetable > air > soil. Consumption of vegetables from greenhouses resulted in significantly higher estrogenic effects compared to those from open field cultivation. This study emphasizes highly potential health risks of PAEs in air-soil-vegetable systems of plastic greenhouses.

Lycopene Prevents DEHP-Induced Liver Lipid Metabolism Disorder by Inhibiting the HIF-1α-Induced PPARα/PPARγ/FXR/LXR System

Di(2-ethylhexyl) phthalate (DEHP) is a widespread pollutant that badly affects animals and human health. Lycopene (LYC) has been used as a dietary supplement that has effective antioxidant and antiobesity functions. The present goal was to understand the molecular mechanisms of LYC preventing DEHP-induced lipid metabolism of the liver. The mice were intragastrically administered with LYC (5 mg/kg) and/or DEHP (500 mg/kg or 1000 mg/kg). Here, we found that LYC attenuated DEHP-caused hepatic histopathological lesions including steatosis. Hematological and biochemical analyses revealed that LYC ameliorated DEHP-caused liver function and lipid metabolism disorders. DEHP caused lipid metabolism disorders via activating the peroxisome proliferator activated receptor α/γ (PPARα/γ) signal transducer and Farnesoid X receptor (FXR)/liver X receptor (LXR) signaling pathway. As a major regulator of lipid metabolism, hypoxia-inducible factor-1α (HIF-1α) system was elevated with increased fatty degeneration under DEHP exposure. However, LYC could decrease the levels of HIF-1α/PPARα/PPARγ/FXR/LXR signaling pathway-related factors. Our research indicated that LYC could prevent DEHP-induced lipid metabolism disorders via inhibiting the HIF-1α-mediated PPARα/PPARγ/FXR/LXR system. This study may provide a possible molecular mechanism for fatty liver induced by DEHP.

Passive air sampling for semi-volatile organic chemicals

During passive air sampling, the amount of a chemical taken up in a sorbent from the air without the help of a pump is quantified and converted into an air concentration. In an equilibrium sampler, this conversion requires a thermodynamic parameter, the equilibrium sorption coefficient between gas-phase and sorbent. In a kinetic sampler, a time-averaged air concentration is obtained using a sampling rate, which is a kinetic parameter. Design requirements for kinetic and equilibrium sampling conflict with each other. The volatility of semi-volatile organic compounds (SVOCs) varies over five orders of magnitude, which implies that passive air samplers are inevitably kinetic samplers for less volatile SVOCs and equilibrium samplers for more volatile SVOCs. Therefore, most currently used passive sampler designs for SVOCs are a compromise that requires the consideration of both a thermodynamic and a kinetic parameter. Their quantitative interpretation depends on assumptions that are rarely fulfilled, and on input parameters, that are often only known with high uncertainty. Kinetic passive air sampling for SVOCs is also challenging because their typically very low atmospheric concentrations necessitate relatively high sampling rates that can only be achieved without the use of diffusive barriers. This in turn renders sampling rates dependent on wind conditions and therefore highly variable. Despite the overall high uncertainty arising from these challenges, passive air samplers for SVOCs have valuable roles to play in recording (i) spatial concentration variability at scales ranging from a few centimeters to tens of thousands of kilometers, (ii) long-term trends, (iii) air contamination in remote and inaccessible locations and (iv) indoor inhalation exposure. Going forward, thermal desorption of sorbents may lower the detection limits for some SVOCs to an extent that the use of diffusive barriers in the kinetic sampling of SVOCs becomes feasible, which is a prerequisite to decreasing the uncertainty of sampling rates. If the thermally stable sorbent additionally has a high sorptive capacity, it may be possible to design true kinetic samplers for most SVOCs. In the meantime, the passive air sampling community would benefit from being more transparent by rigorously quantifying and explicitly reporting uncertainty.