Occurrence, distribution, and sources of organophosphate esters (OPEs) in the air of the Indo-China Peninsula Based on a Passive Air Monitoring Network.

Organophosphate esters (OPEs) are a class of emerging and ubiquitous contaminants that are attracting increasing attention, and their large-scale use as flame retardants and plasticizers has led to their pervasive presence in the environment, although their broader impacts remain unknown. In this study, 11 OPEs were measured in the atmosphere of Southeast Asia and Southwest China during 2016. The ∑11OPEs were higher in this region (78.0-1670 pg/m3, mean 458 pg/m3) than in many remote areas, lower than in developed regions, and comparable to levels in many developing country cities. Generally, the ∑11OPEs were higher in urban (105-1670 pg/m3, mean 538 pg/m3) than in suburban (78.0-1350 pg/m3, mean 388 pg/m3). Seasonal variations of OPEs in the air were more pronounced in Cambodia and Laos, especially for Triphenyl Phosphate (TPHP). Seasonal variations of ∑11OPEs in most regions correspond to changes in temperature and rainfall. Biomass burning may be also a factor in facilitating OPE emissions from biomass materials or soil into the atmosphere of Southeast Asia. The random forest analysis showed that among these, rainfall had the greatest effect on the seasonal variation of atmospheric OPE concentrations, followed by biomass burning and temperature. The inter-regional variation of ∑11OPEs in Southeast Asia was related to population and economic development in each region. Airflow trajectories indicated that the OPEs in this region were mainly from local sources. The health risk assessment revealed that the inhalation exposure risks of OPEs to the residents in the study areas were very low during the sampling period, but may be increasing.

Investigation of alkyl, aryl, and chlorinated OPFRs in sediments from estuarine systems: Seasonal variation, spatial distribution and ecological risks assessment.

Estuaries in South Africa are very important for biodiversity conservation and serve as focal points for leisure and tourism activities. The organophosphate flame retardants (OPFRs) levels in these aquatic systems haven't been documented in any studies as of yet. Due to the negative effects of persistent organic pollutants in South African estuaries, we examined the occurrence of eight OPFRs in sediments of two estuaries by studying their spatiotemporal distribution, season variation, and ecological risks. The Sundays Estuary (SDE), a semi-urbanized agricultural surrounding system, recorded an ∑8OPFR concentration in sediments that ranged from 0.71 to 22.5 ng/g dw, whereas Swartkops Estuary, a largely urbanized system, recorded a concentration that ranged from 0.61 to 119 ng/g dw. Alkyl-OPFRs were the prevalent homologue in both estuaries compared to the chlorinated and aryl groups. While TBP, TCPP, and TCrP were the most abundant compounds among the homologue groups. There was no distinct seasonal trend of ∑8OPFR concentration in either estuary, with summer and autumn seasons recording the highest concentrations in SDE and SWE, respectively. Ecological risks in the majority of the study sites for the detected compounds were at low (RQ < 0.1) and medium levels (0.1 ≤ RQ < 1) for certain species of fish, Daphnia magna and algae. However, the cumulative RQs for all the compounds had ∑RQs ≥1 for most sites in both estuaries, indicating that these organisms, if present in both estuaries, may be exposed to potential ecological concerns due to accumulated OPFR chemicals. The scope of future studies should be broadened to include research areas that are not only focus on the bioaccumulation patterns of these compounds but also find sustainable ways to reduce them from these estuarine environments.

Identification, semi-quantification and risk assessment of contaminants of emerging concern in Flemish indoor dust through high-resolution mass spectrometry.

Indoor dust can contribute substantially to human exposure to known and contaminants of emerging concern (CECs). Novel compounds with high structural variability and different homologues are frequently discovered through screening of the indoor environment, implying that constant monitoring is required. The present study aimed at the identification and semi-quantification of CECs in 46 indoor dust samples collected in Belgium by liquid chromatography high-resolution mass spectrometry. Samples were analyzed applying a targeted and suspect screening approach; the latter based on a suspect list containing >4000 CECs. This allowed the detection of a total of 55 CECs, 34 and 21 of which were identified with confidence level (CL) 1/2 or CL 3, respectively. Besides numerous known contaminants such as di(2-ethylhexyl) phthalate (DEHP), di(2-ethylhexyl) adipate (DEHA) or tris(2-butoxyethyl) phosphate (TBOEP) which were reported with detection frequencies (DFs) > 90%, several novel CECs were annotated. These included phthalates with differing side chains, such as decyl nonyl and decyl undecyl phthalate detected with DFs >80% and identified through the observation of characteristic neutral losses. Additionally, two novel organophosphate flame retardants not previously described in indoor dust, i.e. didecyl butoxyethoxyethyl phosphate (DDeBEEP) and bis(butoxyethyl) butyl phosphate (BBEBP), were identified. The implementation of a dedicated workflow provided semi-quantitative concentrations for a set of suspects. Such data obtained for novel phthalates were in the same order of magnitude as the concentrations observed for legacy phthalates indicating their high relevance for human exposure. From the semi-quantitative data, estimated daily intakes and resulting hazard quotients (HQs) were calculated to estimate the exposure and potential health effects. Neither of the obtained HQ values exceeded the risk threshold, indicating no expected adverse health effects.

Organophosphate Esters in Building Materials from China: Levels, Sources, Emissions, and Preliminary Assessment of Human Exposure.

Source characteristics and health risks of indoor organophosphate esters (OPEs) are limited by the lack of knowledge on emission processes. This study attempted to integrate the contents and emissions of OPEs from indoor building materials to assess human health effects. Thirteen OPEs were investigated in 80 pieces of six categories of building materials. OPEs are ubiquitous in the building materials and ∑13OPE contents varied significantly (p < 0.05) from 72.8 ng/g (seam agent) to 109,900 ng/g (wallpaper). Emission characteristics of OPEs from the building materials were examined based on a microchamber method. Depending on the sample category, the observed initial area-specific emission rates of ∑13OPEs varied from 154 ng/m2/h (carpet) to 2760 ng/m2/h (wooden floorboard). Moreover, the emission rate model was developed to predict the release levels of individual OPEs, quantify source contributions, and assess associated exposure risks. Source apportionments of indoor OPEs exhibited heterogeneities in multiple environmental media. The joint OPE contribution of wallpaper and wooden floorboard to indoor dust was up to 94.8%, while latex paint and wooden floorboard were the main OPE contributors to indoor air (54.2%) and surface (76.1%), respectively. Risk assessment showed that the carcinogenic risks of tris(2-chloroethyl) phosphate (3.35 × 10-7) were close to the acceptable level (1 × 10-6) and deserved special attention.

Multi-pathway exposure assessment of organophosphate flame retardants in a southern Chinese population: Main route identification with compound-specificity.

In this study, we conducted comprehensive organophosphorus flame retardant (PFR) exposure assessments of both dietary and non-dietary pathways in a rural population in southern China. Skin wipes were collected from 30 volunteers. Indoor and outdoor air (gas and particles), dust in the houses of these volunteers, and foodstuffs consumed by these volunteers were simultaneously collected. The total PFR concentrations in dust, gas, and PM2.5 varied from 53.8 to 5.14 × 105 ng/g, 0.528 to 4.27 ng/m3, and 0.390 to 16.5 ng/m3, respectively. The forehead (median of 1.36 × 103 ng/m2) and hand (median of 920 ng/m2) exhibited relatively high PFR concentrations, followed by the forearm (median of 440 ng/m2) and upper arm (median of 230 ng/m2). The PFR concentrations in the food samples varied from 0.0700 to 10.9 ng/g wet weight in the order of egg > roast duck/goose and vegetable > pork > chicken > fish. Tris(1-chloro-isopropyl) phosphate (TCPP) was the main PFR in the non-diet samples, whereas the profiles of PFR individuals varied by food type. Among the multiple pathways investigated (inhalation, dermal exposure, dust ingestion, and food ingestion), dermal absorption and dust ingestion were the predominant pathways for tris(2-chloroethyl) phosphate (TCEP) and bisphenol A-bis(diphenyl phosphate) (BDP), respectively, whereas dietary exposure was the most important route for other chemicals.

Exposure, bioaccumulation, and risk assessment of organophosphate flame retardants in crayfish in the middle and lower reaches of the Yangtze River.

Organophosphate flame retardants (OPFRs), a novel class of persistent pollutants, are widely distributed in the environment, and their potential health risks have garnered significant global attention in recent years. Crayfish is a popular freshwater crustacean product in China primarily sourced from the middle and lower reaches of the Yangtze River. The purpose of this study was to investigate the exposure levels of OPFRs in crayfish, assess the health and safety risks associated with crayfish consumption, and explore the bioaccumulation of OPFRs in environmental water and sediment on crayfish. Ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was employed to analyze 7 common OPFRs in 106 crayfish samples and 76 environmental samples. The results revealed that OPFRs were detected at a high frequency of 100 % in crayfish, with tripropyl phosphate (TPP) being the predominant pollutant found in edible portions while also exhibiting secondary contamination within the crayfish food chain. Monte Carlo modeling combined with @risk risk assessment software demonstrated that TPP present in crayfish muscles had the most substantial impact on health effects, however, overall OPFR exposure did not pose significant risks to human health. Furthermore, analysis of OPFRs bioenrichment ability indicated that crayfish predominantly accumulated these compounds within their edible parts from surrounding environmental water sources, particularly highlighting TPP's potential for bioaccumulation.

Spatial and temporal variability and risk assessment of organophosphate esters in seawater and sediments of the Yangtze River estuary.

Organophosphate esters (OPEs) as substitutes for PBDEs have been widely detected in the marine environment, while little is known about the pollution characteristics and variation of OPEs in estuarine environments with complex hydrodynamic conditions and land-based input. Yangtze River Estuary (YRE) is a typical highly urbanized and industrialized estuary, with a complex hydrological environment and geochemical behavior. This study found that the concentrations of OPEs in both seawater and sediments in the YRE were higher in spring than in summer. Alkyl OPEs were the first contributor, with TnBP and TiBP as the main components, where the contribution of alkyl OPEs had exceeded 75 % in both seawater and sediments in spring, and 60 % in summer seawater, and even 80 % in sediments. In spring, OPEs peaked in the central to southern region near the YRE. In summer, OPEs were mainly concentrated in the southern branch waterway and southern nearshore area of the YRE and showed a decreasing trend to the northeast. The OPEs in the sediments were mainly concentrated in the Yangtze River Mud Area (YREMA) and the Zhe-Min Coastal Mud Area (ZMCMA). Based on the fugacity model and principal component analysis, sediments could be released into the aquatic environment as an endogenous source, and exogenous sources were mainly municipal and industrial sewage discharge sources, urban and marine traffic discharge sources, and atmospheric deposition sources. The ecological risk analysis showed that the Σ14OPEs had exhibited a low to moderate ecological risk in the southern branch waterway and the south-central region offshore.

Global patterns of human exposure to flame retardants indoors.

To fill the knowledge gaps regarding the global patterns of human exposure to flame retardants (FRs) (i.e., brominated flame retardants (BFRs) and organophosphorus flame retardants (OPFRs)), data on the levels and distributions of FRs in external and internal exposure mediums, including indoor dust, indoor air, skin wipe, serum and urine, were summarized and analysed. Comparatively, FR levels were relatively higher in developed regions in all mediums, and significant positive correlations between FR contamination and economic development level were observed in indoor dust and air. Over time, the concentration of BFRs showed a slightly decreasing trend in all mediums worldwide, whereas OPFRs represented an upward tendency in some regions (e.g., the USA and China). The occurrence levels of FRs and their metabolites in all external and internal media were generally correlated, implying a mutual indicative role among them. Dermal absorption generally contributed >60% of the total exposure of most FR monomers, and dust ingestion was dominant for several low volatile compounds, while inhalation was found to be negligible. The high-risk FR monomers (BDE-47, BDE-99 and TCIPP) identified by external exposure assessment showed similarity to the major FRs or metabolites observed in internal exposure mediums, suggesting the feasibility of using these methods to characterize human exposure and the contribution of indoor exposure to the human burden of FRs. This review highlights the significant importance of exposure assessment based on multiple mediums for future studies.

A critical review on organophosphate esters in drinking water: Analysis, occurrence, sources, and human health risk assessment.

Organophosphate esters (OPEs) are ubiquitous in the environment. Copious studies assessed OPEs in various environmental media. However, there is limited summative information about OPEs in drinking water. This review provides comprehensive data for the analytical methods, occurrence, sources, and risk assessment of OPEs in drinking water. In general, liquid-liquid extraction and solid-phase extraction are the most common methods in the extraction of OPEs from drinking water, while gas chromatography and liquid chromatography are the most commonly used instrumental methods for detecting OPEs in drinking water. On the basis of these techniques, a variety of methods on OPEs pretreatment and determination have been developed to know the pollution situation of OPEs. Studies on the occurrence of OPEs in drinking water show that the total concentrations of OPEs vary seasonally and regionally, with tris(1-chloro-2-isopropyl) phosphate and tris(2-chloroethyl) phosphate dominant among different kinds of drinking water. Source identification studies show that there are three main sources of OPEs in drinking water: 1) source water contamination; 2) residual in drinking water treatment process; 3) leakage from device or pipeline. Besides, risk assessments indicate that individual and total OPEs pose no or negligible health risk to human, but this result may be significantly underestimated. Finally, the current knowledge gaps on the research of OPEs in drinking water are discussed and some suggestions are provided for future environmental research.

Occurrence, distribution, sources, and risk assessment of organophosphate esters in typical coastal aquaculture waters of China.

This study monitored 20 organophosphate esters (OPEs) in water and sediment from three typical mariculture bases (Yunxi Marine Ranching (YX), Hangzhou Bay (HZB), and Zhelin Bay (ZLB)) and Meiliang Bay (MLB) of Taihu Lake in China, focusing on the spatial distribution and sources of OPEs. Moreover, the occurrence and risk of OPEs in fishes from ZLB were evaluated. The ∑OPE concentrations in waters followed the order MLB (591 ng/L) > YX (102 ng/L) > HZB (70.0 ng/L) > ZLB (37.4 ng/L), with tri(1-chloro-2-propyl) phosphate (TCIPP), triethyl phosphate (TEP), and tri(2-chloroethyl) phosphate (TCEP) being the dominant OPEs. Significantly higher ∑OPE concentrations were found in sediment in MLB compared to the other three areas with similar levels. The decreasing concentrations of OPEs from nearshore to offshore areas in HZB and MLB indicated that terrigenous input is the main source of OPEs. The even distribution of OPEs in YX and ZLB combined with PCA analysis suggested ship traffic or aquaculture activities are also potential sources. The ∑OPE concentrations in fishes ranged from 0.551-2.45 ng/g wet weight, with TCIPP, tri-phenyl phosphate (TPHP), and TCEP being the main OPEs. Hydrophobicity was a key factor affecting the sediment-water distribution coefficients and the bioaccumulation factors of OPEs. The human exposure to OPEs through consumption of fishes from ZLB had a low health risk.

Assessment of Daily Exposure to Organophosphate Esters through PM2.5 Inhalation, Dust Ingestion, and Dermal Contact.

Inhalation of airborne fine particulate matter (PM2.5), dust ingestion, and dermal contact with dust are important pathways for human exposure to different contaminants, such as organophosphate esters (OPE), compounds that are widely used as flame retardants and plasticizers. There are limited studies assessing the extent of the contamination of OPE in indoor airborne PM2.5. This study offers a novel approach by examining various indoor environments, such as homes, workplaces, and means of transport, where people typically spend their daily lives. The goal is to provide a comprehensive assessment of daily exposure to these pollutants. Both PM2.5 and dust samples were collected in order to determine the concentration levels of 17 different OPEs. Fifteen OPEs in PM2.5 and 16 in dust samples were detected. Concentration levels in indoor air ranged from 4.37 to 185 ng/m3 (median 24.4 ng/m3) and from 3.02 to 36.9 µg/g for the dust samples (median 10.2 µg/g). Estimated daily intakes (EDIs) of OPEs were calculated for adults, yielding median values of 3.97 ng/(kg bw × day) for EDIInhalation, 5.89 ng/(kg bw × day) for EDIDermal, and 1.75 ng/(kg bw × day) for EDIIngestion. Such levels lie below human health threshold risk limits, although in some cases they could be only 2 times below the threshold for carcinogenic risk, with a main contribution from tris(2-chloroethyl) phosphate (TCEP). Given this threshold proximity, additional exposure to these chemicals from other pathways, such as food ingestion, gas phase exposure, and/or inhalation of coarser particles (PM10-2.5), could therefore lead to health limit exceedances.

Distribution characteristics, source attribution, and health risk assessment of organophosphate esters in indoor and outdoor dust from various microenvironments in Beijing.

The occurrence and profiles of organophosphate esters (OPEs) were studied in indoor and outdoor dusts from various microenvironments, including forty-seven outdoor dusts from green belts, roads, parks and residence areas, seventy-seven indoor dusts from private cars, print shops, taxis, furniture shops, offices, dormitories, shopping malls and residences house in different districts in Beijing. The total concentrations (Σ12OPEs) were eighteen times higher in indoor dusts (7.14 ×102 to 2.24 ×104 ng/g) than in outdoor dusts (36.0-1.56 ×103 ng/g). OPEs concentrations in samples from taxi and private cars were obviously higher than other indoor microenvironments. Both indoor and outdoor microenvironments also showed different compositional profiles of OPEs, indicating that polyurethane foam/building materials and hydraulic fluids/plastics were the greatest contributions in different microenvironments, with chlorinated alkyl phosphates (Cl-OPEs) being the predominant compound in both indoor dust (52.1-86.5%) and outdoor dust samples (42.6-81.3%). The uncertainty was reduced by Monte Carlo simulation, and the pollution levels of 50th and 95th percentiles were employed to calculate the average daily dosage, which was then used to calculate hazard quotient (HQ) for assessing the health risks to adults and children. Results showed that OPEs were safe even at extremely consumed concentration percentile (95th) in all groups.

Emerging and traditional organophosphate esters in office air from Hangzhou, East China: Seasonal variations, influencing factors and human exposure assessment.

Eight emerging and six traditional organophosphate esters (OPEs) were investigated in office air from Hangzhou China with all the traditional OPEs and 5 out of 8 emerging OPEs detected. The median concentrations of ∑traditional OPEs and ∑emerging OPEs were 61,200 and 5.81 pg/m3, respectively. Butylphenyl diphenyl phosphate (BPDPP) and trisisopropyltrisphenyl phosphate (TIPPP) were observed for the first time in indoor air and Chinese office, respectively. The levels of ∑traditional OPEs decreased in the following order: summer > autumn > spring > winter. Conversely, no obvious trends were observed for emerging OPEs. ∑traditional OPEs (p < 0.001) and tri(chloroisopropyl) phosphate (TCIPP) (p < 0.01) concentrations were positively correlated with temperature. Interestingly, ∑emerging OPEs and the individual emerging OPEs analytes had no significant correlations with temperature (p > 0.05). ∑traditional OPEs, tris(2-chloroethyl) phosphate (TCEP) and TCIPP levels were significantly positively correlated with relative humidity (p < 0.05), while ∑emerging OPEs levels were negatively correlated with relative humidity (p < 0.05). Median intakes of traditional OPEs were estimated to be several orders of magnitude lower than the corresponding Reference Dose (RfD) values. The distinct environmental behaviors of emerging OPEs compared to traditional OPEs, coupled with the lack of established RfD values for them, underscore the need for their risk evaluations in future.

High-resolution mass spectrometry-based screening and dietary intake assessment of organophosphate esters in foodstuffs from South China.

Organophosphate esters (OPEs) are a group of emerging contaminants with widespread environmental occurrence, yet research on their occurrence in foodstuffs is limited. We collected 100 foodstuff samples in South China using a market basket method, and analyzed food extracts for the presence of OPEs and organophosphite antioxidants (OPAs) by suspect and nontarget screening through high-resolution mass spectrometry. Our analysis resulted in the identification of 30 OPEs, comprised of 25 OPEs with a confidence level (CL) of 1 (unequivocal identification using standards) and five OPEs with CL = 2b (probable structure based on diagnostic evidence). Interestingly, 11 of these identified OPEs had not been previously reported in food. No OPA was identified. The occurrence of identified OPEs within the food samples was further investigated. The highest median concentration of OPEs in all food samples was reached by tris(2-chloroisopropyl) phosphate (TCPP) (1.55 ng/g ww, range < 0.74-12.0 ng/g wet weight (ww)). Cereals demonstrated the highest median concentration of the cumulative 30 OPEs. Tris(2-chloroethyl) phosphate (TCEP), TCPP, and triethyl phosphate (TEP) predominantly contributed to OPEs contamination in most food categories. Eight OPEs, namely TEP, tris(2-ethylhexyl) phosphate (TEHP), TCEP, triphenyl phosphate (TPhP), 2-ethylhexyl diphenyl phosphate (EHDPP), bis(2-ethylhexyl) phenyl phosphate (BEHPP), resorcinol bis(diphenyl phosphate) (RDP), and methyl diphenyl phosphate (MDPP) exhibited significantly higher concentrations in the processed group as compared to non-processed group, suggesting that food processing may result in contamination of these OPEs. The median sum of estimated dietary intake (ΣEDI) of all OPEs was determined to be 161 ng/kg body weight/day. Cereals (38.5 %) and vegetables (23.5 %) were the predominant food categories contributing to ΣEDI, and TEP (29.0 %), TCEP (20.2 %), and TCPP (18.3 %) were three major OPEs contributing to ΣEDI. This study for the first time offered a comprehensive overview of OPE species and revealed their occurrence in foodstuffs from South China.

Health Risk Assessment of Organophosphate Flame Retardants in Soil Across China Based on Monte Carlo Simulation.

Health risks from exposure to contaminants are generally estimated by evaluating concentrations of the contaminants in environmental matrixes. However, accurate health risk assessment is difficult because of uncertainties regarding exposures. This study aims to utilize data on the concentrations of organophosphate flame retardants (OPFRs) in surface soil across China coupled with Monte Carlo simulations to compensate for uncertainties in exposure to evaluate the health risks associated with contamination of soil with this class of flame retardants. Results revealed that concentrations of ∑OPFRs were 0.793-406 ng/g dry weight (dw) with an average of 23.2 ng/g dw. In terms of spatial distribution, higher OPFRs concentrations were found in economically developed regions. Although the values of health risk of OPFRs in soil across China were below the threshold, the high concentrations of OPFRs in soil in some regions should attract more attentions in future. Sensitivity analysis revealed that concentrations of OPFRs in soil, skin adherence factor, and exposure duration were the most sensitive parameters in health risk assessment. In summary, the study indicated that the national scale soil measurement could provide unique information on OPFRs exposure and health risk assessment, which was useful for the management of soil in China and for better understanding of the environmental fate of OPFRs in the global perspective.

Organophosphate esters (OPEs) in plastic food packaging: non-target recognition, and migration behavior assessment.

Organophosphate esters (OPEs) are widely used as plasticizers in plastic food packaging; however, the migration of OPEs from plastic to food is largely unstudied. We do not even know the specific number of OPEs that exist in the plastic food packaging. Herein, an integrated target, suspect, and nontarget strategy for screening OPEs was optimized using ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). The strategy was used to analyze 106 samples of plastic food packaging collected in Nanjing city, China, in 2020. HRMS allowed full or tentative identification of 42 OPEs, of which seven were reported for the first time. Further, oxidation products of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (AO626) in plastics were identified, implying that the oxidation of organophosphite antioxidants (OPAs) could be an important indirect source of OPEs in plastics. The migration of OPEs was examined with four simulated foods. Twenty-six out of 42 OPEs were detected in at least one of the four simulants, particularly isooctane, in which diverse OPEs were detected at elevated concentrations. Overall, the study supplements the list of OPEs that humans could ingest as well as provides essential information regarding the migration of OPEs from plastic food packaging to food.

Organohalogenated flame retardants and organophosphate esters from home and preschool dust in Sweden: Pollution characteristics, indoor sources and intake assessment.

This study analysed settled dust samples in Sweden to assess children's combined exposure to 39 organohalogenated flame retardants (HFRs) and 11 organophosphate esters (OPEs) from homes and preschools. >94 % of the targeted compounds were present in dust, indicating widespread use of HFRs and OPEs in Swedish homes and preschools. Dust ingestion was the primary exposure pathway for most analytes, except BDE-209 and DBDPE, where dermal contact was predominant. Children's estimated intakes of ∑emerging HFRs and ∑legacy HFRs from homes were 1-4 times higher than from preschools, highlighting higher exposure risk for HFRs in homes compared to preschools. In a worst-case scenario, intakes of tris(2-butoxyethyl) phosphate (TBOEP) were 6 and 94 times lower than the reference dose for children in Sweden, indicating a potential concern if exposure from other routes like inhalation and diet is as high. The study also found significant positive correlations between dust concentrations of some PBDEs and emerging HFRs and the total number of foam mattresses and beds/m2, the number of foam-containing sofas/m2, and the number of TVs/m2 in the microenvironment, indicating these products as the main source of those compounds. Additionally, younger preschool building ages were found to be linked to higher ΣOPE concentrations in preschool dust, suggesting higher ΣOPE exposure. The comparison with earlier Swedish studies indicates decreasing dust concentrations for some banned and restricted legacy HFRs and OPEs but increasing trends for several emerging HFRs and several unrestricted OPEs. Therefore, the study concludes that emerging HFRs and OPEs are replacing legacy HFRs in products and building materials in homes and preschools, possibly leading to increased exposure of children.

Screening of organophosphate esters in different indoor environments: Distribution, diffusion, and risk assessment.

ANALYSIS: of air conditioner (AC) filter dust can reveal the level of organophosphate ester (OPE) pollution in indoor environments, but comprehensive research on this topic remains lacking. This study combined non-targeted and targeted analysis to screen and analyze 101 samples of AC filter dust, settled dust, and air obtained in 6 indoor environments. Phosphorus-containing organic compounds account for a large proportion of the organic compounds found in indoor environments, and OPEs might be the main pollutants. Using toxicity data and traditional priority polycyclic aromatic hydrocarbons for toxicity prediction of OPEs, 11 OPEs were prioritized for further quantitative analysis. The concentration of OPEs in AC filter dust was highest, followed in descending order by that in settled dust and that in air. The concentration of OPEs in AC filter dust in the residence was two to seven times greater than that in the other indoor environments. More than 56% of the OPEs in AC filter dust showed significant correlation, while those in settled dust and air were weakly correlated, suggesting that large amounts of OPEs collected over long periods could have a common source. Fugacity results showed that OPEs were transferred easily from dust to air, and that dust was the main source of OPEs. The values of both the carcinogenic risk and the hazard index were lower than the corresponding theoretical risk thresholds, indicating low risk to residents through exposure to OPEs in indoor environments. However, it is necessary to remove AC filter dust in a timely manner to prevent it becoming a pollution sink of OPEs that could be rereleased and endanger human health. This study has important implications for comprehensive understanding of the distribution, toxicity, sources, and risks of OPEs in indoor environments.

Organophosphite Antioxidants and Novel Organophosphate Esters in Dust from China: Large-Scale Distribution and Heterogeneous Phototransformation.

A large-scale survey was conducted by measuring five organophosphite antioxidants (OPAs) and three novel organophosphate esters (NOPEs) in 139 dust samples across China. The median summed concentrations of OPAs and NOPEs in outdoor dust were 33.8 ng/g (range: 0.12-53,400 ng/g) and 7990 ng/g (2390-27,600 ng/g), respectively. The dust concentrations of OPAs associated with the increasing economic development and population density from western to eastern China, whereas the NOPE concentration in Northeast China (median, 11,900 ng/g; range, 4360-16,400 ng/g) was the highest. Geographically, the distribution of NOPEs was significantly associated with annual sunshine duration and precipitation at each sampling site. Results of laboratory experiments further revealed that the simulated sunlight irradiation promoted the heterogeneous phototransformation of OPAs in dust, and this process was accelerated with the existence of reactive oxygen species and enhanced relative humidity. Importantly, during this phototransformation, the hydroxylated, hydrolyzed, dealkylated, and methylated products, e.g., bis(2,4-di-tert-butylphenyl) methyl phosphate, were identified by nontargeted analysis, part of which were estimated to be more toxic than their parent compounds. The heterogeneous phototransformation pathway of OPAs was suggested accordingly. For the first time, the large-scale distribution of OPAs and NOPEs and the phototransformation of these "new chemicals" in dust were revealed.

Consumption of fruits and vegetables contaminated with pesticide residues in Brazil: A systematic review with health risk assessment.

Brazil is the third largest exporter of fruits and vegetables in the world and, consequently, uses large amounts of pesticides. Food contamination with pesticide residues (PRs) is a serious concern, especially in developing countries. Several research reports revealed that some Brazilian farmers spray pesticides on fruits and vegetables in large quantities, generating PRs after harvest. Thus, ingestion of food contaminated with PRs can cause adverse health effects. Based on information obtained through a systematic review of essential information from 33 articles, we studied the assessment of potential health risks associated with fruit and vegetable consumption in children and adults from Brazilian states. This study identified 111 PRs belonging to different chemical groups, mainly organophosphates and organochlorines, in 26 fruit and vegetable samples consumed and exported by Brazil. Sixteen of these PRs were above the Maximum Residue Limit (MRL) established by local and international legislation. We did not identify severe acute and chronic dietary risks, but the highest risk values were observed in São Paulo and Santa Catarina, associated with the consumption of tomatoes and sweet peppers due to the high concentrations of organophosphates. A high long-term health risk is associated with the consumption of oranges in São Paulo and grapes in Bahia due to chlorothalonil and procymidone. We also identified that 26 PRs are considered carcinogenic by the United States Environmental Protection Agency (US EPA), and the carcinogenic risk analysis revealed no severe risk in any Brazilian state investigated due to the cumulative hazard index (HI) < 1. However, the highest HI values were in São Paulo due to acephate and carbaryl in sweet pepper and in Bahia due to dichlorvos. This information can help regulatory authorities define new guidelines for pesticide residue limits in fruits and vegetables commonly consumed and exported from Brazil and monitor the quality of commercial formulations.