OPEs-ID: A software for non-targeted screening of organophosphate esters based on liquid chromatography-high-resolution mass spectrometry.

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers, presenting a potential threat to the environment and human health. To date, no automatic software exists for the nontargeted screening of OPEs. In this study, OPEs-ID, a user-friendly software, was developed for the identification of OPEs using liquid chromatography-high-resolution mass spectrometry. The main workflow of OPEs-ID included fragments-dependent precursor ion screening, elemental composition determination, extracted ion chromatograms (EIC) comparison, and molecular structure identification via MetFrag strategy. A mixture of 17 OPE standards was identified with an identification rate of 100% by OPEs-ID. OPEs-ID demonstrated a rate of 94.1% for correctly ranking within the top 1 candidate in a local database (41.2% in PubChem) for the 17 OPE standards, which remarkably improved the identification when compared to conventional in silico fragmentation algorithms. Using a pooled airborne fine particle sample (PM2.5), OPEs-ID could automatically retrieve 22 valid molecules with structure candidates. The detection frequencies of 9 newly identified OPEs were between 13% and 100% in the 32 PM2.5 samples. Their semi-quantification concentrations were comparable to those of some traditional OPEs. Overall, OPEs-ID offers a powerful tool to significantly enrich our understanding of the OPEs present in the environment.

Plastic additive components of PM2.5 increase corrected QT interval: Screening for exposure markers based on airborne exposome.

The impact of industrial chemical components of ambient fine particles (e.g. PM2.5) on cardiovascular health has been poorly explored. Our study reports for the first time the associations between human exposure to complex plastic additive (PA) components of PM2.5 and prolongation of heart rate-corrected QT (QTC) interval by employing a screening-to-validation strategy based on a cohort of 373 participants (136 in the screening set and 237 in the validation set) recruited from 7 communities across China. The high-throughput airborne exposome framework revealed ubiquitous occurrences of 95 of 224 target PAs in PM2.5, totaling from 66.3 to 555 ng m-3 across the study locations. Joint effects were identified for 9 of the 13 groups of PAs with positive associations with QTC interval. Independent effect analysis also identified and validated tris(2-chloroisopropyl) phosphate, di-n-butyl/diisobutyl adipate, and 3,5-di-tert-butyl-4-hydroxybenzaldehyde as the key exposure markers for QTC interval prolongation and changes of selected cardiovascular biomarkers. Our findings highlight the important contributions of airborne industrial chemicals to the risks of cardiovascular diseases and underline the critical need for further research on the underlying mechanisms, toxic modes of action, and human exposure risks.

Emission inventories, emission factors, and composition profiles of volatile organic compounds (VOCs) and heavy metals (HMs) from an e-waste dismantling park in southern China.

Electronic waste (e-waste) dismantling is a significant source of atmospheric pollutants, including volatile organic compounds (VOCs) and heavy metals (HMs), which may have adverse effects on the surrounding environment and residents. However, the organized emission inventories and emission characteristics of VOCs and HMs from e-waste dismantling are not well documented. In this study, the concentrations and components of VOCs and HMs were monitored at the exhaust gas treatment facility from two process areas of a typical e-waste dismantling park in southern China in 2021. Emission inventories of VOCs and HMs were established, with total emissions of 8.85 t/a and 18.3 kg/a for VOCs and HMs in this park, respectively. The cutting & crushing (CC) area was the largest emissions source, accounting for 82.6% of VOCs and 79.9% of HMs, respectively, while the baking plate (BP) area had higher emission factors. Additionally, the concentration and composition of VOCs and HMs in the park were also analyzed. For VOCs, the concentrations of halogenated hydrocarbons and aromatic hydrocarbons were comparable in the park, while m/p-xylene, o-xylene, and chlorobenzene were the key VOC species. The HM concentrations followed the order of Pb > Cu > Mn > Ni > As > Cd > Hg, with Pb and Cu being the main heavy metals released. This is the first VOC and HM emission inventory for the e-waste dismantling park, and our data will lay a solid ground for pollution control and management for the e-waste dismantling industry.

Characterization of short-, medium- and long-chain chlorinated paraffins in ambient PM2.5 from the Pearl River Delta, China.

Research on the environmental occurrence of long-chain chlorinated paraffins (LCCPs) in ambient fine particulate matter (PM2.5) is still scarce. In the present study, short-chain chlorinated paraffins (SCCPs), medium-chain chlorinated paraffins (MCCPs) and LCCPs were simultaneously quantified and profiled in PM2.5 samples collected from 96 primary or secondary schools in the Pearl River Delta of South China. SCCPs, MCCPs and LCCPs were detected in higher than 90% samples with concentrations in the range of 0.832-109, 1.02-110, and 0.173-17.4 ng/m3, respectively. The dominant congener groups of SCCPs, MCCPs and LCCPs were C13Cl6-8, C14Cl7-8, and C18Cl7-9, respectively. The concentrations of SCCPs and MCCPs were higher in summer than in winter, while an opposite seasonal trend was observed for LCCPs. Principal components analysis showed there were seasonal variations in the congener group patterns with C13Cl6-7 and C14Cl7 more abundant in summer than in winter. Concentrations of CPs also exhibited slight spatial variations. Exposure risk assessment based on different age groups suggested exposure to PM2.5-associated CPs would not pose significant health risk. The present study expands the existing knowledge of CPs contamination in atmospheric environment.

Screening for Bisphenol Chemicals: A Strategy Based on Dansyl Chloride Derivatizatio n Coupled with In-Source Fragmentation by High-Resolution Mass Spectrometry.

Bisphenol chemicals (BPs) represent a complexity of halogenated and nonhalogenated substances sharing a common structure of two phenol functionalities, some of which exhibit ubiquitous environmental distributions and endocrine-disrupting activities. However, environmental monitoring of complex BP-like chemicals has faced analytical challenges arising from the lack of commercially available reference standards and efficient screening strategies. In the present study, we developed a strategy based on dansyl chloride (DnsCl) derivatization in combination with in-source fragmentation (D-ISF) during high-resolution mass spectrometry analysis to screen for bisphenol chemicals in complex environmental samples. The strategy contains three steps, including DnsCl derivatization to enhance the detection sensitivity by one to more than four orders of magnitude, in-source fragmentation to produce characteristic loss of 234.0589, 63.9619, and 298.0208 Da for the identification of DnsCl-derivatized compounds, and data processing and annotation. The D-ISF strategy was further validated and then applied to identify BPs in six types of particular matters as representative environmental samples, including settled dust from an electronic waste dismantling site, homes, offices, and vehicles, and airborne particles from indoor and outdoor environments. A total of six halogenated and fourteen nonhalogenated BPs were identified in the particles, including several chemicals that had rarely or never been identified in environmental samples. Our strategy offers a powerful tool for the environmental monitoring of bisphenol chemicals and assessment of human exposure risks.

Exposure to legacy and alternative flame retardants in two harbor seal populations and the association with blubber fatty acid profiles.

Flame retardants (FRs) are ubiquitously present in various environmental compartments due to widespread application. However, there have been few reports on the alternative FRs in harbor seals, and their relationship with fatty acid (FA) profiles have largely been overlooked. Here, we investigated the levels of legacy and alternative FRs and FA profiles in the blubber of harbor seals from the coasts of South Sweden (2009-2016) and Northeastern US (NE US) (1999-2010). We observed different proportions of mono- and poly-unsaturated FAs (MUFAs and PUFAs) between the two populations, which may reflect variations in the diet. Significantly higher concentrations of ΣPBDE were also observed in harbor seals from US compared to those from Sweden, both dominated by BDE 47. By comparison, the levels of alternative FRs, noticeably HBBZ and PBEB were much lower compared to those of PBDEs. Moreover, we found a positive correlation between BDE 99 and Σn-6/Σn-3 PUFA in harbor seals from Sweden. In addition, BDE 153 and BDE 154 were positively correlated with ΣUFA/ΣSFA in seals from Sweden and US, respectively. Our results imply the influence of diet in FA profiles and FR concentrations in top predators, as well as the importance of blubber FA characteristics in indicating FR exposure. Further investigations are required to assess the risk of exposure in these harbor seals, as well as to elucidate the underlying mechanisms associating FA profiles with FR exposure.

Preconception exposure to perfluoroalkyl and polyfluoroalkyl substances and couple fecundity: A couple-based exploration.

Numerous studies have examined the adverse health effects of perfluoroalkyl and polyfluoroalkyl substances (PFAS) but it remains unclear whether preconception exposure to PFAS affects couple fecundity. This prospective preconception cohort study with 936 Chinese couples aimed to comprehensively assess the effects of PFAS on couple fecundity [measured by the time to pregnancy (TTP)] and infertility (i.e., TTP > 12 menstrual cycles) with a focus on the effects of partner-specific exposure and joint-effects of couple-based exposure. Twenty-five PFAS were quantified in plasma from each partner, including seven branched isomers, two chlorinated polyfluoroalkyl ether sulfonic acids, four emerging PFAS replacements [i.e., 6:2 fluorotelomer phosphate diester (6:2 diPAP) and three short-chain alternatives: perfluoro-n-butanoicacid, perfluorobutane sulfonate and perfluoroheptanoic acid (PFHpA)]. Using a two-phase regression approach composed of elastic net regression and principal component analysis, we found that exposure to 6:2 diPAP and PFHpA rather than legacy PFAS in women and the couple-based exposure patterns characterized by high level of female 6:2 diPAP were significantly associated with reduced couple fecundity, which was independent of the adjustment of co-exposed PFAS homogenous from both partners. For example, a ln unit increase in female 6:2 diPAP was associated with 15 % [fecundity odds ratio (FOR) = 0.85, 95 %CI: 0.76, 0.96)] lower odds of couple fecundability (i.e., longer TTP) and 45 % increased risk of infertility [OR = 1.45 (95 %CI: 1.16, 1.81)], respectively. While most PFAS in men were not associated with couple fecundity, certain PFAS (e.g., perfluorohexane sulfonic acid) in men were negatively associated with infertility risk. However, the combined effects of PFAS mixture in couples were nonsignificant. Our findings suggest that PFAS in men and women may exert different impacts on couple fecundity. Preconception exposure to 6:2 diPAP and PFHpA in women may have the potential to impair couple fecundity.

Distribution of flame retardants among indoor dust, airborne particles and vapour phase from Beijing: spatial-temporal variation and human exposure characteristics.

The occurrence and distribution of 10 brominated flame retardants (BFRs) and 10 organophosphate flame retardants (OPFRs) were investigated in indoor dust, total suspended particles (TSP), and vapour phase from offices (n = 10), homes (n = 9), and day-care centres (n = 10) in Beijing, China. Three types of samples were collected biweekly from one office and one home over a year to examine temporal trends. BFRs in dust significantly correlated with those in TSP, while OPFRs significantly correlated among all three matrices. In addition, BFRs in dust (ng/g) and TSP (pg/m3) exhibited similar temporal trends with higher levels in the cold season, whereas OPFRs in TSP and vapour phase (pg/m3) showed similar temporal trends with higher levels in the warm season. The geometric mean concentrations of BFRs and OPFRs in the three matrices from the above mentioned three types of indoor microenvironments were used for exposure and health risk estimation, and ∑7OPFRs showed much higher hazard index (HI) values than ∑10BFRs for all subpopulations, and inhalation of OPFRs was a major risk source. With the volatility of flame retardants (FRs) decreasing, the contribution of dust ingestion and dermal absorption showed an increasing trend, and the contribution of inhalation exhibited a gradual decreasing trend, which implied the dominant exposure pathway to FRs is strongly related to the vapour pressure (25 °C, Pa) of these substances. Using a single type of microenvironment or the collection of samples at a single point in time can lead to overestimation or underestimation of overall exposure and risk for people to some extent. The correlations of FRs in dust, TSP, and vapour phase from indoor microenvironments, as well as their temporal trends were first reported in this study, which will provide a basis for more accurate FR exposure assessments in the future.

Perfluoroalkyl substances (PFASs) as risk factors for breast cancer: a case-control study in Chinese population.

BACKGROUND: Perfluoroalkyl substances (PFASs) are a large family of synthetic chemicals, some of which are mammary toxicants and endocrine disruptors. Recent studies have implicated exposure to PFASs as a risk factor for breast cancer in Europe and America. Little is known about the role of PFASs with respect to breast cancer in the Chinese population. METHODS: Participants who were initially diagnosed with breast cancer at Tianjin Medical University Cancer Institute and Hospital between 2012 and 2016 were recruited as cases. The controls were randomly selected from the participants with available blood samples in the Chinese National Breast Cancer Screening Program (CNBCSP) cohort. Ultimately, we enrolled 373 breast cancer patients and 657 controls. Plasma PFASs were measured by an ultra-performance liquid chromatography (UPLC) system coupled to a 5500 Q-Trap triple quadrupole mass spectrometer. A logistic regression model with least absolute shrinkage and selection operator (LASSO) regularization was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to assess the relationships between PFASs and breast cancer. The three most predictive variables in the LASSO model were selected from 17 PFASs, which was based on the optimal penalty coefficient (λ = 0.0218) identified with the minimum criterion. Additionally, Bayesian kernel machine regression (BKMR) and quantile g-computation models were applied to evaluate the associations between separate and mixed exposure to PFASs and breast cancer. RESULTS: Perfluorooctanesulfonic acid (PFOS) exhibited the highest concentration in both the cases and controls. Perfluorooctanoic acid (PFOA) and perfluoro-n-decanoic acid (PFDA) were positively associated with breast cancer, and perfluoro-n-tridecanoic acid (PFTrDA) was negatively associated with breast cancer according to both the continuous-PFASs and the quartile-PFASs logistic regression models. Of note, PFOA was associated with the occurrence of estrogen receptor (ER)-, progesterone receptor (PR)-, and human epidermal growth factor receptor 2 (HER2)-positive breast cancer (ORER+ = 1.47, 95% CI: 1.19, 1.80; ORPR+ = 1.36, 95% CI: 1.09, 1.69; ORHER2 = 1.62, 95% CI: 1.19, 2.21). CONCLUSIONS: Overall, we observed that PFASs were associated with breast cancer in Chinese women. Prospective cohort studies and mechanistic experiments are warranted to elucidate whether these associations are causal.

Environmental Exposure to 6:2 Polyfluoroalkyl Phosphate Diester and Impaired Testicular Function in Men.

6:2 polyfluoroalkyl phosphate diester (6:2 diPAP) has been demonstrated to disrupt reproductive endocrine functions using experimental studies. However, evidence from humans is not available yet. This cross-sectional study aims to assess the relationship between 6:2 diPAP exposure and the testicular function among adult men. A total of 902 men seeking preconception care were included. Plasma 6:2 diPAP concentrations were determined, while the testicular function was assessed via semen quality and reproductive hormones in serum. The association was assessed by multiple linear regression. Stratified analyses by age and body mass index (BMI) were conducted to assess the potential effect modification by these two variables. Regression analyses revealed that 6:2 diPAP exposure was significantly inversely associated with androgens [i.e., total testosterone (TT) and free androgen index (FAI)], markers of testosterone production potential [i.e., TT/luteinizing hormone (LH) and FAI/LH], estradiol, and insulin-like factor 3, a biomarker of Leydig cell function. These associations were robust in sensitivity analyses. However, age and BMI did not modify these associations, and no association was observed between 6:2 diPAP and semen quality. Our study suggests that exposure to 6:2 diPAP may inhibit androgen synthesis and impair Leydig cell function in adult men.

Environmental exposure to legacy poly/perfluoroalkyl substances, emerging alternatives and isomers and semen quality in men: A mixture analysis.

BACKGROUND/OBJECTIVES: Multiple studies have examined the relationship between PFAS and semen quality, but none has explored the associations of PFAS mixture that includes emerging alternatives and branched isomers. METHODS: 22 PFAS, including 10 linear legacy PFAS, 7 branched isomers, 3 short chain alternatives and 2 components of F53B [e.g., 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFESA)] were quantified in blood plasma among 740 healthy men. Five semen quality parameters (i.e., volume, count, concentration, total motility and progressive rate) were assessed. Multiple linear regression and three multiple pollutant models (i.e., adaptive elastic net regression, quantile based g-computation, and XGBoost method) were used to assess the associations of individual PFAS and PFAS mixture with semen quality and the potential interactive effects among congeners. RESULTS: After adjusting for selected confounders, perfluorobutane sulfonate (PFBS) and perfluorohexane sulfonate (PFHxS) presented significant and negative associations with sperm count [ßAENET = -0.09 (95%CI: -0.14, -0.03) for PFBS, and -0.16 (95%CI: -0.25, -0.07) for PFHxS] and sperm concentration [-0.04 (95%CI: -0.08, -0.001) for PFBS and -0.11 (95%CI: -0.17, -0.04) for PFHxS]. 6:2 Cl-PFESA showed negative associations with total motility (-2.33, 95%CI: -3.80, -0.86) and progressive rate (-1.46, 95%CI: -2.79, -0.12). But perfluoroheptanesulfonic acid (PFHpS) was positively associated with sperm count and concentration. These associations were supported by the importance assessment of these four congeners in XGBoost analyses. However, no associations were found between PFAS mixture or branched isomers and semen quality; nor were there significant interactions among PFAS congeners. CONCLUSIONS: In the current cross-sectional study, we found that two emerging PFAS replacements (i.e., 6:2 Cl-PFESA and PFBS) and PFHxS exposure were associated with reduced semen concentration, total sperm count and motility in men. Meanwhile, significant positive associations between PFHpS and sperm count and concentration were also observed. But there were no consistent associations between PFAS mixture, branched isomers and semen quality.

Bisphenol A and its analogues in paired urine and house dust from South China and implications for children's exposure.

Following the restriction of bisphenol A (BPA) in certain products, a number of bisphenol analogues (BPs) have been used as BPA replacements in different applications, raising environmental and health concerns. The present study determined a total of 13 bisphenol analogues in house dust and children urine from South China families (n = 46). Among all BPs, BPA, bisphenol S (BPS) and bisphenol F (BPF) were frequently detected in house dust, with concentrations ranging from 0.54 to 26.2 µg/g (median: 2.60 µg/g), 0.07-11.5 µg/g (median: 0.32 µg/g) and 0.02-2.4 µg/g (median: 0.29 µg/g), respectively. BPA (median: 2.43 ng/mL) was also the dominant BP in children urine samples, accounting for 75.2 ± 27.4% of the total concentrations of urinary BPs, followed by BPS (0.23 ng/mL), whereas BPF was only detected in less than 30% of urine samples. Children's daily intake of bisphenols through dust ingestion and total daily intakes were estimated based on the dust and urine concentrations, respectively. The estimated intake of BPA, BPS and BPF via house dust ingestion accounted for 9%, 12% and 38% of the total intakes predicted based on urinary concentrations, respectively, and exhibited very low exposure risks.

Exposure of Preconception Couples to Legacy and Emerging Per- and Polyfluoroalkyl Substances: Variations Within and Between Couples.

Exploration of the exposure of preconception couples to per- and polyfluoroalkyl substances (PFAS), as well as the most important influencing factors, promotes the understanding of the joint effects of parental exposure on reproductive health. In the present study, a total of 938 preconception couples recruited through the Shanghai Birth Cohort were investigated for the variations of PFAS exposure and contributing factors within and between couples. While linear perfluorooctanoic acid (n-PFOA, median 20.4 ng/mL) and linear perfluorooctanesulfonic acid (n-PFOS, 12.1 ng/mL) remained dominant in plasma, emerging PFAS, particularly 6:2 chlorinated polyfluorinated ether sulfonate (10.5 ng/mL), 6:2 polyfluoroalkyl phosphate diester (0.41 ng/mL), and branched PFOS or PFOA isomers, were also frequently detected. Although individual PFAS were generally correlated within couples, gender differences significantly existed in the concentrations of most individual PFAS and isomer profiles of PFOS and PFOA. Men generally exhibited higher plasma concentrations than their partners, likely reflecting gender-specific elimination pathway and kinetics. Couple-based PFAS exposure also varied greatly. After adjustment for individual factors, several household factors, including annual household income, dwelling floor type, drinking water source, and living near farmlands, were found to be associated with couple-based PFAS exposure. Our study constitutes one of the few studies addressing couple-based exposure to PFAS and lays a solid ground for further assessment of the impacts of parental exposure on reproductive health.

Chemical-specific determinants for pre-conceptional exposure to emerging and legacy per- and polyfluoroalkyl substances.

The exposure of preconception women to per- and polyfluoroalkyl substances (PFASs) could negatively affect her reproductive health. However, chemical-specific determinants for pre-conceptional exposure to PFASs, particularly the emerging ones, remain poorly understood. In the present study, it was found that the total PFAS concentration ranged from 8.9 to 440.3 ng/mL (median: 49.6 ng/mL) in 1060 preconception women. The PFAS exposure profile was dominated by PFOA (16.8 ng/mL), followed by PFOS (13.3 ng/mL), 6:2 Cl-PFESA (8.9 ng/mL), PFDA (2.4 ng/mL), PFNA (2.1 ng/mL), and others. The pre-conceptional exposure to the selected PFASs was significantly associated, in a chemical-specific pattern, with multiple demographic characteristics and the consumption frequency of different types of food. In particular, the exposure to 6:2 Cl-PFESA was associated with age, parity, alcohol drinking, educational level, household income, and the consumption frequency of red meat, marine and freshwater fish, shellfish, and shrimp. However, our analysis revealed that the investigated sociodemographic and diet variables only explained a relatively small proportion (1.3%-18.7%) of PFAS concentration variations, raising the need of exploring additional factors critical to pre-conceptional PFAS exposure. Overall, the identification of chemical-specific determinants would greatly facilitate the understanding of the link between pre-conceptional exposure and health outcomes, and the mitigation of human exposure to PFAS, particularly the emerging ones.

Gas-particle partition and size-segregated distribution of flame retardants in indoor and outdoor air: Reevaluation on the role of fine particles in human exposure.

In this study, we investigated the distribution of brominated and organophosphate flame retardants (BFRs and OPFRs) in the paired gaseous and nine size-segregated particulate samples collected from 8 typical indoor compartments and monthly outdoor in Xinxiang, China, respectively. For the indoor environments, total concentrations of FRs (Σ19FRs) in bulk air ranged from 3.9 ng/m3 to 37.5 ng/m3, with that in children recreation center (37.5 ng/m3) and furniture store (28.7 ng/m3) showing highest levels. In the outdoor air, Σ19FRs ranged from 3.1 ng/m3 to 13.6 ng/m3 among the 12 months, with that from late spring and summer being the highest. OPFRs had higher concentration than BFRs, with the total concentration of OPFRs accounting for 77%-99% of ∑19FRs. TCIPP (tris(chloroiso-propyl) phosphate), TCEP (tris(2-chloroethyl) phosphate), TEP (triethyl phosphate) and DBDPE (decabromodiphenyl ethane), BDE-209 (decabromodiphenyl ether) were the predominant analogs. Specifically, BFRs tended to enrich in gas phase indoors and coarse particles (aerodynamic diameters >3.3 µm) outdoors, but OPFRs mainly distributed in coarse particles both indoors and outdoors. The size distribution patterns varied among FRs, with the higher volatile FRs (e.g., TCEP, TCIPP) distributed more uniformly across particulate size. Although the distribution patterns of FRs in air were driven by multiple factors, organic carbon and element carbon in particulate matter had an influence to a certain extent. Health risks from exposure to FRs were characterized via the hazard quotient approaches. The total noncarcinogenic risks of ∑16FRs from inhalation were higher than that from air to skin transport, and the risks resulted from coarse particle-bound ∑16FRs (>3.3 µm) and gas phase were both significantly higher than that from fine fraction (<3.3 µm) in all scenarios, implying that FRs in coarse particles should not be underestimated.

[Characterization and Exposure Risk Assessment of Non-phthalate Plasticizers in House Dust from Guangzhou].

Although non-phthalate plasticizers are widely used in various consumer products as substitutes for phthalates, currently little is known about their environmental occurrence and the risks of human exposure. To characterize the pollution and human exposure risk in indoor environments, house dust samples collected from 83 households in Guangzhou were analyzed for twelve typical non-phthalate plasticizers. Results showed that dioctyl terephthalate (DEHT), trioctyl trimellitate (TOTM), acetyl lemon tributyl ester (ATBC), heptylnonyl adipate, di(2-ethylhexyl) adipate, and trioctyl trimellitate were detected in all samples. The total concentrations of non-phthalate plasticizers ranged from 22.4 to 615 µg ·g-1 with a median of 101 µg ·g-1. DEHT had the highest concentrations (9-487 µg ·g-1), followed by TOTM (0.3-87 µg ·g-1) and ATBC (1.7-50 µg ·g-1). Daily intakes via dust ingestion for adults and children were estimated based on the dust concentrations. The total daily intake of children was 367 ng ·(kg ·d)-1, which was 8-9 times higher than that of adults[43 ng ·(kg ·d)-1]. Further risk assessment through the hazard quotient approach showed that the exposure of adults and children to non-phthalic plasticizers via dust ingestion was within an acceptable risk range.

Exposure of children and mothers to organophosphate esters: Prediction by house dust and silicone wristbands.

Ubiquitous human exposure to organophosphorus tri-esters (tri-OPEs) has been reported worldwide. Previous studies investigated the feasibility of using house dust and wristbands to assess human OPE exposure. We hypothesized that these two approaches could differ in relative effectiveness in the characterization of children and adult exposure. In the participants recruited from Guangzhou, South China, urinary levels of major OPE metabolites, including diphenyl phosphate (DPHP) and bis(butoxyethyl) phosphate (BBOEP), were significantly higher in children than their mothers (median 6.6 versus 3.7 ng/mL and 0.11 versus 0.06 ng/mL, respectively). The associations of dust or wristband-associated OPEs with urinary metabolites exhibited chemical-specific patterns, which also differed between children and mothers. Significant and marginally significant associations were determined between dust concentrations of triphenyl phosphate (TPHP), tris(2-butoxyethyl) phosphate (TBOEP), trimethylphenyl phosphate (TMPP), or tris(1-chloro-2-propyl) phosphate (TCIPP) and their metabolites in children urine and between dust tris(1,3-dichloroisopropyl) phosphate (TDCIPP), TPHP or TMPP and urinary metabolites in mothers. By contrast, wristbands exhibited better efficiency of predicting internal exposure to TDCIPP. While both house dust and wristbands exhibited the potential as a convenient approach for assessing long-term OPE exposure, their feasibility requires better investigations via larger-scale studies and standardized sampling protocols.

Plastic additives and personal care products in south China house dust and exposure in child-mother pairs.

Indoor environment constitutes an important source of industrial additive chemicals to human exposure. We hypothesized that the influence of residential environment on human exposure varies among different types of additive chemicals and differs between children and mothers. This study determined a suite of additive chemicals in house dust from South China dwellings (n = 47) and urine from child-mother pairs. Concentrations of phthalates (PAEs; median 601 µg/g) were 2-3 orders of magnitude greater than those of parabens (0.82 µg/g), bisphenols (3.31 µg/g), and benzophenone-related chemicals (2.69 µg/g). Urinary concentrations differed between children and mothers, but the pattern of differences varied between chemical groups. Children exhibited greater urinary levels of mono-PAEs than mothers (510 versus 395 ng/mL, p = 0.152), while the latter population exhibited greater levels of parabens and benzophenones. Regression analyses indicate a lack of association between dust and urinary levels for most chemicals, suggesting that other exposure pathways can complicate human exposure scenarios. Indeed, we estimated that the daily intake via dust ingestion only constituted 0.002-0.81% of total daily intake estimated based on urine data for mothers and 0.04-5.61% for children. Future efforts are needed to better characterize source-specific exposure for different populations.