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This study examined the effects of hot high-fat simulants on the physicochemical properties of microplastics (MPs) from polypropylene (PP)-, low-density polyethylene (LDPE)-, and polylactic acid (PLA)-based single-use food container (SUFC) leachates and those of aging on their immunomodulatory effectors. Scenario studies have demonstrated that MPs were released from these three types of SUFCs. LDPE- and PLA-based SUFCs also released cellulose. Among the SUFCs, only the PP leachates particles exhibited a new absorption peak at 1725 cm−1, which aging phenomenon may be attributed to the presence of unstable tertiary carbon atoms. Subsequently, we investigated the immunomodulatory effects of removing additive both PP and thermal-aged PP with polystyrene (PS) and carboxyl-modified PS (PS-COOH) polymer backbones as reference materials. The findings indicated that thermal-aged PP and PS-COOH induced comparable innate immune responses, with PS-COOH particles exhibiting a similar size to SUFC percolates. Consequently, PS and PS-COOH were selected as original and thermal-aged MPs, respectively, to evaluate the effects of aging on innate immunity. The results revealed that a protein corona formed on both particle types, with more protein adsorption observed on PS-COOH particles. The complex enhanced the phagocytosis of RAW264.7 macrophages and increased the expression of pro-inflammatory genes NOS2 and TNF-α through an actin polymerization cross-linking mechanism. In this study, we investigated how thermal-aged MPs affect innate immune responses using PS-COOH as a model system, emphasizing the importance of a comprehensive safety evaluations of MPs.

Currently, there is limited knowledge regarding occupational exposure of traditional and emerging organophosphate esters (OPEs) from e-waste and automobile dismantling activities, and their distribution within the human blood. In the present study, we collected dust and urine samples from e-waste (ED) (n = 91 and 130, respectively) and automobile dismantling (AD) plants (n = 93 and 94, respectively), as well as serum-plasma-whole blood samples (sets from 128 participants) within ED areas for analyzing traditional and emerging organophosphate tri-esters (tri-OPEs) and organophosphate di-esters (di-OPEs). Median concentration of ∑tri-OPEs and ∑di-OPEs in dust (37,400 and 9,000 ng/g in ED, and 27,000 and 14,700 ng/g in AD areas, respectively) and urine samples (11.8 and 21.9 ng/mL in ED areas, and 17.2 and 15.0 ng/mL in AD areas, respectively) indicated that both e-waste and automobile dismantling activities served as important pollution source for OPEs. Dust ingestion has been evidenced to be the main exposure pathway compared to dermal absorption and inhalation. The median concentration (ng/mL) of OPEs in blood matrices descended order as follow: whole blood (13.1) > serum (11.6) > plasma (10.4) for ∑tri-OPEs, and plasma (3.51) > serum (0.36) > whole blood (0.23) for ∑di-OPEs. Concentration ratios of OPEs varied across blood matrices, depending on the compounds, suggesting that the essentiality of appropriate biomonitoring matrix for conducting comprehensive exposure assessments.

Automotive interiors have been identified as significant sources of various chemicals, yet their occupational hazards for end-of-life vehicle (ELV) dismantlers remain poorly characterized. Herein, eight classes of plasticizers, including 11 phthalates esters (PAEs) and 16 non-phthalates esters (NPAEs), were detected in dust samples from inside and outside ELV dismantling workshops. Moreover, indoor dust from ordinary households and university dormitories was compared. The indoor dust from the ELV dismantling workshops contained the highest concentrations of plasticizers (median: 594 μg/g), followed by ordinary households (296 µg/g), university dormitories (186 µg/g), and outdoor dust (157 µg/g). PAEs remained the dominant plasticizers, averaging 11.7-fold higher than their NPAE alternatives. Specifically, diisononyl phthalate and trioctyl trimellitate were notably elevated in workshop dust, being 15.5 and 4.78 times higher, respectively, than in ordinary household dust, potentially indicating their association with ELV dismantling activities. The estimated daily intake of occupational ELV dismantling workers was up to five times higher than that of the general population. Moreover, certain dominant NPAEs demonstrated nuclear receptor interference abilities comparable to typical PAEs, suggesting potential toxic effects. This study is the first to demonstrate that ELV dismantling activities contribute to the co-emission of PAEs and NPAEs, posing a substantial risk of exposure to workers, which warrants further investigation.

Recently, evidence of aromatic amine antioxidants (AAs) existence in the dust of the electronic waste (e-waste) dismantling area has been exposed. However, there are limited studies investigating occupational exposure and toxicity associated with AAs and their transformation products (p-phenylenediamines-quinones, i.e., PPD-Qs). In this study, 115 dust and 42 hand wipe samples collected from an e-waste recycling industrial park in central China were analyzed for 19 AAs and 6 PPD-Qs. Notably, the median concentration of ∑6PPD-Qs (1,110 ng/g and 1,970 ng/m2) was significantly higher (p

Herein, the trapping effectiveness of N95, filter KN95, medical surgical masks (MSMs), and disposable medical masks (DMMs) against 19 airborne traditional and novel organophosphate esters (OPEs) was evaluated. Laboratory simulations (n = 24 for each type of mask) showed that time-dependent accumulation of ∑19OPEs on the four types of masks ranged between 30.1 and 86.6 ng in 24 h, with the highest and lowest median amounts trapped by the N95 masks (53.3 ng) and DMMs (43.2 ng), respectively. The trapping efficiency of the four types of masks for ∑19OPEs decreased over time from 84 % to 39 % in 24 h, with N95 masks showing the highest median efficiency (70 %). Further, field investigations were conducted in five types of microenvironments (train, hospital, bus, supermarket, and canteen), and an analysis of 200 samples showed that ∑19OPEs were accumulated in the masks with a variable amount from 3.7 to 117 ng/mask. Consistent with the laboratory simulations, the N95 masks (29.0 ng/mask) exhibited the highest hourly median amount of trapped OPEs, followed by the KN95 masks (24.5 ng/mask), MSMSs (17.4 ng/mask), and DMMs (15.8 ng/mask). Triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), and cresyl diphenyl phosphate (CDP) as well as 4-isopropylphenyl diphenyl phosphate (4IPPDPP) and 2,4-diisopropylphenyl diphenyl phosphate (24DIPPDPP) were the most commonly detected traditional and novel OPEs. Based on the amount of OPEs trapped on the masks, we estimated the concentration of ∑19OPEs in the train microenvironment to be the highest (222 ng/m3), which is approximately 2–5 times higher than that in the other microenvironments. The results of this study prove that masks can effectively protect humans from exposure to OPEs and act as low-cost indicators of indoor contamination.

Organophosphate esters (OPEs) are a group of pollutants that are widely detected in the environment at high concentrations. They can adversely affect human health through multiple routes of exposure, including dermal uptake. Although attention has been paid to achieving an accurate and complete quantification of the dermal uptake of OPEs, existing evaluation methods and parameters have obvious weaknesses. This study reviewed two main categories of methodologies, namely the relative absorption (RA) model and the permeability coefficient (PC) model, which are widely used to assess the dermal uptake of OPEs. Although the PC model is more accurate and is increasingly used, the most important parameter in this model, the permeability coefficient (Kp), has been poorly characterised for OPEs, resulting in considerable errors in the estimation of the dermal uptake of OPEs. Thus, the detailed in vitro methods for the determination of Kp are summarised and sorted. Furthermore, the commonly used skin membranes are identified and the factors affecting Kp and corresponding mechanisms are discussed. In addition, the experimental conditions, conclusions, and available data on Kp values of the OPEs are thoroughly summarised. Finally, the corresponding knowledge gaps are proposed, and a more accurate and sophisticated experimental system and unknown Kp values for OPEs are suggested.

Liquid crystal monomers (LCMs) are widely used chemicals and ubiquitous emerging organic pollutants in the environment, some of which have persistent, bio-accumulative, and toxic potentials. Elevated levels of LCMs have been found in the e-waste dismantling associated areas. However, information on their internal exposure bio-monitoring is scarce. For the first time, occurrences of LCMs were observed in the serum samples of occupational workers (n = 85) from an e-waste dismantling area in South China. Twenty-nine LCMs were detected in serum samples of the workers, with a median value of 35.2 ng/mL (range: 7.78–276 ng/mL). Eight noticed LCMs were found to have relatively high detection frequencies ranging from 52.9% to 96.5%. The correlation analysis of individual LCMs indicated potential common applications and similar sources to the LCMs in occupational workers. Fluorinated LCMs were identified as the predominant monomers in the workers. Additionally, the estimated daily intake of the LCMs in the occupational workers was significantly higher than those in residents from the reference areas (p

Melamine (MEL) and its derivatives are increasingly applied as nitrogenous flame retardants in consumer products. Nevertheless, limited information is available on their environmental occurrence and subsequent human exposure via multiple exposure pathways. In this study, we analysed MEL and its derivatives in dust (indication of the dust ingestion route) and hand wipe samples (indication of the hand-to-mouth route) collected in various microenvironments. The levels of ∑MELs in both dust (median: 24,100 ng/g) and participant hand samples (803 ng/m2) collected in e-waste dismantling workshops were significantly higher than those in samples collected in homes (15,600 ng/g and 196 ng/m2, respectively), dormitories (13,100 ng/g and 227 ng/m2, respectively) and hotel rooms (11,800 ng/g and 154 ng/m2, respectively). Generally, MEL dominated in dust samples collected in e-waste dismantling workshops, whereas cyanuric acid dominated in hand wipe samples. This may occur partly because the latter is an ingredient in disinfection products, which are more frequently employed in daily lives during the COVID-19 pandemic. Exposure assessment suggests that dust ingestion is an important exposure pathway among dismantling workers and the general population, whereas hand-to-mouth contact could not be overlooked in certain populations, such as children and dismantling workers not wear gloves at work.

Novel brominated flame retardants (NBFRs) have been widely used as alternatives to legacy BFRs. However, information on the contamination status and human exposure risks of electronic waste (e-waste)-derived NBFRs in the e-waste workplace is limited. In this study, six NBFRs and the legacy BFRs, hexabromocyclododecanes (HBCDs), were analyzed in 50 dust samples from an e-waste-dismantling workplace in Central China. The dust concentration of NBFRs in e-waste-dismantling workshops (median, 157–169 ng/g) was found to be significantly higher than those in an outdoor environment (17.3 ng/g) (p < 0.01). Differently, the highest median concentration of HBCDs was found in dust from the dismantling workshop for cellphones and computers (367 ng/g) among studied areas. The bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEHTBP) was the predominant compound, which contributed 66.0–88.0% of measured NBFR concentrations. NBFRs might originate from plastic and rubber materials in wastes based on the correlation and principal component analysis. Moreover, the total estimated daily intakes (average scenario) of NBFRs were calculated at 2.64 × 10−2 ng/kg bw/d and 2.91× 10−2 ng/kg bw/d for the male and female dismantling workers, respectively, via dust ingestion, inhalation, and dermal contact pathways, which were lower than the reference dose values, and thus indicated a limited human exposure risk for NBFRs at the current level. Although the dust concentrations and daily intakes of NBFRs were still lower than those of other emerging pollutants (e.g., organophosphate and nitrogenous flame retardants) measured in the same sampling set, the elevated levels of NBFRs suggested the progressive BFR replacement process in China, which deserves more attention regarding their adverse effects on both the environment and human health.

Electronic waste (e-waste) is a well-known source of plastic additives in the environment. However, the e-waste-related occupational exposure to organophosphite antioxidants (OPAs) and the relevant oxidation products—novel organophosphate esters (NOPEs)—via different pathways is still unknown. In this study, six OPAs and three NOPEs were measured in 116 dust and 43 hand-wipe samples from an e-waste dismantling area in Central China. The median concentrations of ΣOPAs and ΣNOPEs were 188 and 13,900 ng·g−1 in workshop dust and 5,250 ng·m−2 and 53,600 ng·m−2 on workers’ hands, respectively. The increasing concentrations of dust in the form of triphenyl phosphate (TPHP) (p