Comprehensive Exposure Assessment Research Articles

A comprehensive assessment of external exposure to persistent halogenated organic pollutants for residents in an e-waste recycling site, South China

Human skin wipes from 30 participants, air, dust, and food items were collected from a former electronic waste site in South China to provide a comprehensive understanding of residents' exposure to halogenated flame retardants (HFRs) and polychlorinated biphenyls (PCBs). The total concentration of halogenated organic pollutants (HOPs) in the dust, air, food and skin wipes ranged 240–25000 ng/g, 130–2500 pg/m3, 0.08–590 ng/g wet weight, and 69–28000 ng/m2, respectively. Wild fish, vegetables, and air were dominated by PCBs, whereas dust, livestock, and poultry were dominated by HFRs. The HOP concentrations were several orders of magnitude higher in local foodstuffs than in market foodstuffs. The chemical composition on the forehead was remarkably different from that on the hand. The importance of different exposure routes depends on the residents’ food choices, except decabromodiphenyl ethane (DBDPE). For residents who consumed a 100-foot diet (mainly egg) and local wild fish, diet ingestion overwhelmed other exposure routes, and PCBs were mainly contributed by fish and HFRs by egg. For residents who consumed market food, the dermal absorption of most PCB congeners and dust ingestion of highly brominated flame retardants were relatively prominent. Inhalation was found to be a crucial route for pentabromoethylbenzene (PBEB).

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.

Monitoring and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Mainstream Cigarette Smoke

Objectives : Cigarette smoking is an important factor in human exposure to polycyclic aromatic hydrocarbons (PAHs). Machine-smoking methods have been devised to evaluate inhalation exposure to mainstream cigarette smoke. However, there have been only a few studies that have employed these methods for PAH monitoring in Korea.Methods : Total particulate matter samples were collected from the mainstream smoke of five different cigarette types using the ISO 3308 standard smoking method. The samples were analyzed for 16 PAHs using a gas chromatograph/mass spectrometer (GC/MS) following extraction and clean-up procedures.Results and Discussion : The 16 PAH levels of cigarette samples ranged from 87.1 ng/cig to 247.4 ng/cig with an average of 135.4 ng/cig. The average fractions of PAHs classified by the number of rings were as follows: 15% (2 rings), 37% (3 rings), 43% (4 rings), 4% (5 rings), and 1% (6 rings). Diagnostic ratios suggested that the characteristics of PAH pollution in mainstream cigarette smoke were similar to those of biomass burning but different from those of ambient air. The carcinogenic risks of PAHs exceeded the risk threshold of the US EPA (1.0E-06) for the 10%, 30%, and 20% exposure groups of adult males, adult females, and all adults, respectively.Conclusion : This study highlights the significance of mainstream cigarette smoke in examining human inhalation exposure to PAHs and carcinogenic risks, which are primarily influenced by cigarette smoking rather than ambient air. These findings can contribute to a comprehensive assessment of inhalation exposure to PAHs and provide guidance for the development of environmental health policies aimed at reducing such exposure.

Assessing adverse childhood experiences in young refugees – development of the BRACE questionnaire

Abstract Background With the persistence of ongoing crises and subsequent displacement of individuals, including children, knowledge about adversities experienced in this context is crucial, given the harmful effects of adverse childhood experiences (ACE) on mental and physical health. With the tools currently available, a comprehensive assessment of adversity exposure faced by refugee children is not possible. The BRACE (beyond refugee ACE) project set out to develop a core set of screening items that are refugee children specific and measure exposure and severity at all stages of migration. Here, the development of the Arabic (one of the majority languages of asylum seekers in Europe) parent report version is described. Methods The BRACE questionnaire was developed based on results of 1) a qualitative study involving semi-structured interviews with 47 refugee parents and 11 children (Germany, 2018-2020), and 2) a systematic review of relevant measures. Categories and associated adverse/protective experiences derived in 1) built the foundation of the BRACE. Whenever possible, items of validated ACE tools identified in 2) were used to assess exposure. The item set was finalized after translation into Arabic and cognitive pre-testing with 12 participants from the target population. Results The developed BRACE consisted of 52 items for 48 categories covering 8 adverse (e.g. disruption, violence) and 2 protective themes (e.g., connections). 19 items were developed by the study team (e.g., police brutality), 33 items were adopted from existing ACE tools (e.g. family member arrest). A binary response format expanding into a 4-point Likert scale was employed. Minor difficulties regarding respondent interpretation and answering ability could be resolved resulting in a final 50 item set. Conclusions This item set provides a starting point for field trials of a measure needed to facilitate the identification of at-risk individuals for targeted interventions. Key messages • Adverse childhood experiences (ACE) can harm mental/physical health. Adequate tools assessing ACE exposure in flight contexts are needed in order to develop mitigation strategies for those at risk. • The BRACE project has developed a core set of screening items specific to refugee children's experiences to measure adversity exposure and severity at all stages of migration.

Mass Movement Hazard and Exposure in the Himalaya

AbstractHimalaya is experiencing frequent catastrophic mass movement events such as avalanches and landslides, causing loss of human lives and infrastructure. Millions of people reside in critical zones potentially exposed to such catastrophes. Despite this, a comprehensive assessment of mass movement exposure is lacking at a regional scale. Here, we developed a novel method of determining mass movement trajectories and applied it to the Himalayan Mountain ranges for the first time to quantify the exposure of infrastructure, waterways, roadways, and population in six mountain ranges, including Hindu Kush, Karakoram, western Himalaya, eastern Himalaya, central Himalaya, and Hengduan Shan. Our results reveal that the exposure of buildings and roadways to mass movements is highest in Karakoram, whereas central Himalaya has the highest exposed waterways. The hotspots of exposed roadways are concentrated in Nepal, the North Indian states of Uttarakhand, Himachal Pradesh, the Union Territory of Ladakh, and China's Sichuan Province. Our analysis shows that the population in the central Himalaya is currently at the highest exposure to mass movement impacts. Projected future populations based on Shared Socio‐economic and Representative Concentration Pathways suggest that changing settlement patterns and emission scenarios will significantly influence the potential impact of these events on the human population. Assessment of anticipated secondary hazards (glacial lake outburst floods) shows an increase in probable headward impacts of mass movements on glacial lakes in the future. Our findings will support researchers, policymakers, stakeholders, and local governments in identifying critical areas that require detailed investigation for risk reduction and mitigation.

Occurrence, placental transfer, and health risks of emerging endocrine-disrupting chemicals in pregnant women

Previous studies demonstrated that many environmental chemicals can cross the human placental barrier. However, the risk regarding gestational exposure of emerging endocrine-disrupting chemicals (EDCs) is unclear. In this study, the occurrence of 24 EDCs, such as bisphenol A analogs, parabens, triclocarban, and triclosan, was investigated in serum and urine samples from Chinese pregnant women. Some metabolites were determined in matched serum–urine pairs (n = 75) to perform a comprehensive assessment of exposure. The placental transfer efficiency (PTE) of the detected chemicals was determined in matched maternal–cord serum pairs (n = 110). The mean PTEs of the chemicals showed a large variation from 43.1% to 171.0%. The potential effects of physicochemical properties, molecular structures, and biological factors on PTE were investigated using multiple linear regression models and molecular docking. We found that the PTE of methyl paraben, ethyl paraben, and propyl paraben was associated with their increasing alkyl chain lengths. Furthermore, a comprehensive exposure assessment of EDCs showed that 62.7% of pregnant women had a health index > 1, which indicted potential health risks during pregnancy. However, toxicity and the underlying mechanisms of these EDCs remain to be further studied.

Informing a Comprehensive Risk Assessment of Infant Drug Exposure From Human Milk: Application of a Physiologically Based Pharmacokinetic Lactation Model for Sotalol.

Characterization of infant drug exposure through human milk is important and underexplored. Because infant plasma concentrations are not frequently collected in clinical lactation studies, modeling and simulation approaches can integrate physiology, available milk concentrations, and pediatric data to inform exposure in breastfeeding infants. A physiologically based pharmacokinetic model was built for sotalol, a renally eliminated drug, to simulate infant drug exposure from human milk. Intravenous and oral adult models were built, optimized, and scaled to an oral pediatric model for a breastfeeding-relevant age group (<2years). Model simulations captured the data that were put aside for verification. The resulting pediatric model was applied to predict the impacts of sex, infant body size, breastfeeding frequency, age, and maternal dose (240 and 433mg) on drug exposure during breastfeeding. Simulations suggest a minimal effect of sex or frequency on total sotalol exposure. Infants in the 90th percentile in height and weight have predicted exposures ≈20% higher than infants of the same age in the 10th percentile due to increased milk intake. The simulated infant exposures increase throughout the first 2weeks of life and are maintained at the highest concentrations in weeks 2-4, with a consistent decrease observed as infants age. Simulations suggest that breastfeeding infants will have plasma concentrations in the lower range observed in infants administered sotalol. With further validation on additional drugs, physiologically based pharmacokinetic modeling approaches could use lactation data to a greater extent and provide comprehensive information to support decisions regarding medication use during breastfeeding.

Dietary Exposure and Health Risk of the Emerging Contaminant Fluorinated Liquid-Crystal Monomers.

Fluorinated liquid-crystal monomers (FLCMs) widely used in liquid crystal displays are considered to be a new generation of persistent, bioaccumulative, and toxic contaminants. They have been widely detected in the environment. However, little is known about their occurrence in food and human dietary exposure until now. Herein, we provided an evaluation of dietary exposure and health risks of FLCMs in the Chinese adult population based on the fifth and sixth total diet studies (TDSs). The detection frequencies of FLCMs in the two surveys were 90.5 and 99.5%, with concentrations ranging from not detected ∼72.6 μg/kg wet weight (ww) and ND ∼74.7 μg/kg ww, respectively. All TDS samples contained the multiresidue of FLCMs. The mean estimated daily intakes (EDIs) of FLCMs were 172.86 and 163.10 ng/kg bw/day in the fifth and sixth TDS, respectively. Meats, vegetables, and cereals contributed the most to the EDI of FLCMs. According to the threshold of toxicological concern (TTC) method, the EDIs of 1-fluoro-4-[2-(4-propylphenyl)ethynyl]benzene (4.56 and 3.26 ng/kg bw/day) and 2-fluoro-4-[4'-propyl-1,1'-bi(cyclohexyl)-4-yl]phenyl trifluoromethyl ether (3.12 and 3.28 ng/kg bw/day) were above their TTC value (2.5 ng/kg bw/day), suggesting their potential health risk. This is the first comprehensive national dietary exposure assessment of FLCMs.

Non-negligible health risks caused by inhalation exposure to aldehydes and ketones during food waste treatments in megacity Shanghai

Aldehydes and ketones in urban air continue to receive regulatory and scientific attention for their environmental prevalence and potential health hazard. However, current knowledge of the health risks and losses caused by these pollutants in food waste (FW) treatment processes is still limited, especially under long-term exposure. Here, we presented the first comprehensive assessment of chronic exposure to 21 aldehydes and ketones in urban FW-air environments (e.g., storage site, mechanical dewatering, and composting) by coupling substantial measured data (383 samples) with Monte Carlo-based probabilistic health risk and impact assessment models. The results showed that acetaldehyde, acetone, 2-butanone and cyclohexanone were consistently the predominant pollutants, although the significant differences in pollution profiles across treatment sites and seasons (Adonis test, P < 0.001). According to the risk assessment results, the estimated cancer risk (CR; mean range: 1.6 × 10−5-1.12 × 10−4) and non-cancer risk (NCR; mean range: 2.98–22.7) triggered by aldehydes and ketones were both unacceptable in most cases (CR: 37.8%–99.3%; NCR: 54.2%–99.8%), and even reached the limit of concern to CR (1 × 10−4) in some exposure scenarios (6.18%–16.9%). Application of DALYs (disability adjusted life years) as a metric for predicting the damage suggested that exposure of workers to aldehydes and ketones over 20 years of working in FW-air environments could result in 0.02–0.14 DALYs per person. Acetaldehyde was the most harmful constituent of all targeted pollutants, which contributed to the vast majority of health risks (>88%) and losses (>90%). This study highlights aldehydes and ketones in FW treatments may be the critical pollutants to pose inhalation risks.

Polyvictimization Among Sexual and Gender Minority Youth

Polyvictimization is a significant public health issue. Sexual and gender minority youth are important to include in polyvictimization research because they report higher rates of victimization than nonsexual and gender minority youth. This study examines whether polyvictimization attenuates the associations between individual types of victimization and depressed mood and substance use across gender and sexual identities. Data were collected cross-sectionally from 3,838 youth aged 14-15 years. Youth were recruited through social media between October 2018 and August 2019 across the U.S. Analyses were conducted in July 2022. Sexual and gender minority youth were oversampled. Depressed mood and substance use were dependent variables. Transgender boys were the most likely to be polyvictims (25%). Transgender girls (14.2%) and cisgender sexual minority girls (13.4%) also reported high rates. Cisgender heterosexual boys were the least likely to be classified as polyvictims (4.7%). When adjusting for polyvictimization, existing relationships between individual types of victimization (e.g., theft) and depressed mood became nonsignificant in most cases. Of exception, witnessing violence and peer victimization remained significant predictors of the odds of depressed mood. Most associations between individual types of victimization and substance use became nonsignificant after considering polyvictimization, with the exception of cisgender heterosexual boys and girls, for whom many remained significant but attenuated (e.g., emotional interpersonal violence). Sexual and gender minority youth experience a disproportionate number of victimizations across multiple domains. A comprehensive assessment of victimization exposure may be important when considering prevention and intervention approaches for depressed mood and substance use.

GLOF hazard, exposure, vulnerability, and risk assessment of potentially dangerous glacial lakes in the Bhutan Himalaya

Deglaciation due to atmospheric warming has led to the formation and expansion of numerous glacial lakes, especially in the eastern Himalaya. Many of these glacial lakes are susceptible to glacial lake outburst floods (GLOFs), which can cause far-reaching impacts on downstream infrastructure and livelihoods. This study is a comprehensive assessment of GLOF susceptibility, hazard, exposure, vulnerability, and risk for four potentially dangerous glacial lakes (Bechung Tsho, Raphstreng Tsho, Thorthomi Tsho, and Lugge Tsho) located in the Lunana glacier complex of the Phochu basin in Bhutan. Exposure and risk assessments were based on modelled GLOF hydrodynamics, infrastructure data, population and housing census data. Among the four glacial lakes, Thorthormi Tsho and Lugge Tsho are relatively more susceptible to outburst floods than Raphstreng Tsho and Bechung Tsho. Outflow flood volumes from these lakes range between 6 × 105 and 3 × 108 m3 which can potentially impact over 16,000 people, two hydropower projects, numerous other infrastructures, and agricultural land up to 150 km downstream of the lakes. The GLOF exposed elements are largely in Punakha and Wangdue Phodrang districts, which are located 90 and 100 km downstream of the Lunana glacier complex respectively. Among 17 subdistrict blocks within the basin, one (Lunana) lies in a very high GLOF risk area, while 9 others are in the high GLOF risk zone. The study highlights the importance of multi-source data in improving the knowledge of downstream GLOF risk and serves as a base for improving GLOF risk reduction strategies in high mountain regions.

Wearable Passive Samplers for Assessing Environmental Exposure to Organic Chemicals: Current Approaches and Future Directions.

We are continuously exposed to dynamic mixtures of airborne contaminants that vary by location. Understanding the compositional diversity of these complex mixtures and the levels to which we are each exposed requires comprehensive exposure assessment. This comprehensive analysis is often lacking in population-based studies due to logistic and analytical challenges associated with traditional measurement approaches involving active air sampling and chemical-by-chemical analysis. The objective of this review is to provide an overview of wearable passive samplers as alternative tools to active samplers in environmental health research. The review highlights the advances and challenges in using wearable passive samplers for assessing personal exposure to organic chemicals and further presents a framework to enable quantitative measurements of exposure and expanded use of this monitoring approach to the population scale. Overall, wearable passive samplers are promising tools for assessing personal exposure to environmental contaminants, evident by the increased adoption and use of silicone-based devices in recent years. When combined with high throughput chemical analysis, these exposure assessment tools present opportunities for advancing our ability to assess personal exposures to complex mixtures. Most designs of wearable passive samplers used for assessing exposure to semi-volatile organic chemicals are currently uncalibrated, thus, are mostly used for qualitative research. The challenge with using wearable samplers for quantitative exposure assessment mostly lies with the inherent complexity in calibrating these wearable devices. Questions remain regarding how they perform under various conditions and the uncertainty of exposure estimates. As popularity of these samplers grows, it is critical to understand the uptake kinetics of chemicals and the different environmental and meteorological conditions that can introduce variability. Wearable passive samplers enable evaluation of exposure to hundreds of chemicals. The review presents the state-of-the-art of technology for assessing personal exposure to environmental chemicals. As more studies calibrate wearable samplers, these tools present promise for quantitatively assessing exposure at both the individual and population levels.

Wastewater-based epidemiology for the assessment of population exposure to chemicals: The need for integration with human biomonitoring for global One Health actions

WBE has now become a complimentary tool in SARS-CoV-2 surveillance. This was preceded by the established application of WBE to assess the consumption of illicit drugs in communities. It is now timely to build on this and take the opportunity to expand WBE to enable comprehensive assessment of community exposure to chemical stressors and their mixtures. The goal of WBE is to quantify community exposure, discover exposure-outcome associations, and trigger policy, technological or societal intervention strategies with the overarching aim of exposure prevention and public health promotion. To achieve WBE’s full potential, the following key aspects require further action: (1) Integration of WBE-HBM (human biomonitoring) initiatives that provide comprehensive community-individual multichemical exposure assessment. (2) Global WBE monitoring campaigns to provide much needed data on exposure in low- and middle-income countries (LMICs) and fill in the gaps in knowledge especially in the underrepresented highly urbanised as well as rural settings in LMICs. (3) Combining WBE with One Health actions to enable effective interventions. (4) Advancements in new analytical tools and methodologies for WBE progression to enable biomarker selection for exposure studies, and to provide sensitive and selective multiresidue analysis for trace multi-biomarker quantification in a complex wastewater matrix. Most of all, further developments of WBE needs to be undertaken by co-design with key stakeholder groups: government organisations, health authorities and private sector.

Geographic differences in exposures to metals and essential elements in pregnant women living in Suriname.

In Suriname, 20% of pregnancies end in adverse birth outcomes. While prenatal exposure to metals may lead to adverse health outcomes, exposure assessments in Suriname are scant. Environmental contamination from mercury (Hg) used in artisanal goldmining in the Amazonian Interior, and the uncontrolled use of pesticides in suburban regions are of particular concern. This study assessed geographic differences in exposures to metals and essential elements in pregnant Surinamese women. This study is a subset (n = 400) of the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH) cohort study. Sector-field inductively-coupled plasma mass spectrometry was used to determine concentrations of lead (Pb), Hg, selenium (Se), cadmium (Cd), manganese (Mn) and tin (Sn) in whole blood of the pregnant women. High vs. low exposures to Pb and Hg were determined and were based respectively on CDC (3.5 ug/dL) and USEPA (3.5 ug/L) action levels. Differences in geographic exposures were tested with the Mann-Whitney U-test, and differences between blood elemental concentrations and action levels for Pb and Hg with the Wilcoxon signed rank test. The association between demographics and high exposures of Pb and Hg was examined with multivariate logistic regression models. The median concentrations of Pb, Hg and Se (5.08 μg/dL, 7.87 μg/L, and 228.26 μg/L respectively) in Interior women, were higher than the Urban and Suburban regions (p < 0.001), and higher than internationally accepted action levels (p < 0.001). The median concentrations of Mn and Sn found in Suburban women (17.55 and 0.97 ug/L respectively) were higher than Urban and Interior regions (p < 0.02). Pregnant women living in Suriname's Amazonian Interior are exposed to Hg and Pb at levels of public health concern. Urgently needed is a comprehensive source characterization assessment and the development, implementation and monitoring of environmental health policies, specifically addressing the chemicals of concern. In a subset of participants enrolled in the CCREOH environmental epidemiology cohort study elevated levels of Hg and Pb were identified. This is the first comprehensive exposure assessment in the Surinamese population. Health concerns include adverse birth- and neurodevelopmental outcomes. Geographic differences require a tailored approach to health intervention and comprehensive source characterization. Future research should ascertain the role of Se as a potential protective factor. Environmental policy development, implementation and monitoring is pivotal to mitigate exposures to these neurotoxicants.

Occurrence and Dietary Exposure Assessment to Enniatin B through Consumption of Cereal-Based Products in Spain and the Catalonia Region.

Enniatin B (ENNB) is a mycotoxin produced by moulds from the Fusarium genera and its toxic effects are still not fully elucidated, hence a safe reference exposure value has not been established yet. ENNB is the most prevalent emerging mycotoxin and is widely found in cereal-based products, nevertheless, there are no comprehensive exposure assessment studies. For that reason, the aim of this study was to characterise the occurrence of ENNB and estimate the exposure of the Spanish and Catalan populations. A total of 347 cereal-based products were collected in 2019 and were analysed using liquid chromatography-tandem mass spectrometry. Consumption data were obtained from the national food consumption surveys (ENALIA) and a regional survey conducted in Catalonia. The global exposure was estimated using deterministic and probabilistic methods. The results showed a high occurrence of close to 100% in all foodstuffs, with a range from 6 to 269 µg/kg, and a strong correlation with the levels of deoxynivalenol. Children aged one-nine years were the most exposed, showing mean estimates in the range 308-324 ng/kg bw/day and 95th percentiles 697-781 ng/kg bw/day. This study stresses the need for further toxicological data to establish reference doses and conclude formal risk assessment, accounting for the co-occurrence with deoxynivalenol.

Migration Modeling as a Valuable Tool for Exposure Assessment and Risk Characterization of Polyethylene Terephthalate Oligomers

Polyethylene terephthalate (PET) is one of the most widely used food contact materials due to its excellent mechanical properties and recyclability. Migration of substances from PET and assessment of compliance are usually determined by experimental testing, which can be challenging depending on the migrants of interest. Low concentrations and missing reference standards, among other factors, have led to inadequate investigation of the migration potential of PET oligomers. Migration modeling can overcome such limitations and is therefore a suitable starting point for exposure and risk assessment. In this study, the activation energy-based (EA) model and the AP model were used to systematically evaluate the migration potential of 52 PET oligomers for 12 different application scenarios. Modeling parameters and conditions were evaluated to investigate their impact and relevance on the assessment of realistic exposures. Obtained results were compared with safety thresholds known from the concept of toxicological thresholds of concern. This allowed the evaluation and identification of oligomers and/or applications where migration or exposure levels may be associated with a potential risk because they exceed these safety thresholds. Overall, this study demonstrated that migration modeling can be a high-throughput, fast, flexible, and suitable approach for comprehensive exposure assessment.

A new insight into the emission source of DDT in indoor environment from rural area of South China and comprehensive human health exposure assessment.

Human exposure to dichlorodiphenyltrichloroethanes (DDTs) and the subsequent risk to human health remain an important concern due to the "new" input of DDTs in the environment, especially since exposure to DDTs in indoor microenvironments is often ignored. In this study, we identified a new source of DDT emission in indoor environments and evaluated the health risk from the exposure to DDTs by investigating DDTs in indoor and outdoor dust, air, and coatings of household items in rural areas of Qingyuan, South China. The concentrations of DDTs in house dust and air were < MQL (method quantification limit)-3450ng/g (median 42.4ng/g) and 22.7-965pg/m3 (median 49.5pg/m3), respectively, which were significantly higher than the outdoor DDT values. Dichlorodiphenyldichloroethylene (DDE) was the main isomer in air samples, while DDT was the dominant isomer in indoor dust. Significant correlations between different DDT isomers were observed in indoor samples but not in outdoor samples. Furniture coating was identified as a source of DDTs in the indoor dust. The total daily exposure dose of DDTs (1.75 × 10-2ng/kg bw/day for adults and 1.28 × 10-1ng/kg bw/day for toddlers) through inhalation, dust ingestion, and dermal contact was found unlikely to pose a health risk. Our findings provide new insights into the emission sources and health risks caused by DDT indoors, highlighting the need to further investigate the toxicity mechanisms of parent DDT compound.

Organochlorine pesticides and polychlorinated biphenyls in carnivorous waterbird species from Lake Ziway, Ethiopia

This study presents the assessment of bioaccumulation and reproductive health risk associated with organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) exposure in carnivorous waterbird species. We investigated OCPs and PCBs exposure in muscle tissues of 4 species of carnivorous waterbird species from Lake Ziway, Ethiopia. The influences of trophic position and size on accumulation of organochlorine pollutants are investigated. The result shows that Dichloro-diphenyl-trichloroethanes (DDTs), Endosulfan and PCBs are detected. DDTs constitute the dominant contaminant among OCPs investigated. Trophic position and wing chord length are positively associated with levels of ∑DDTs. Mean levels of ∑DDTs and ∑PCBs vary from 143.9 to 1051.1 ng g−1 wet weight (ww) and not detected (ND)—3.5 ng g−1 ww, respectively. Mean levels of 4,4′-dichloro-diphenyl-dichloro-ethylene (p,p′-DDE), and 4,4′-dichloro-diphenyl-dichloro-ethane (p,p′-DDD) are significantly varied among the bird species. p,p′-DDE contribute 92.3–98.6% of total DDTs. About 26.7% of birds show p,p′-DDE levels above the minimum threshold to cause reproductive failures in birds. Generally, the findings of this study shows that DDT exposure in high trophic levels bird species from Lake Ziway could result in reproductive health risk. The present study may serve as a baseline for future comprehensive exposure and risk assessment studies.Article Highlightsp,p’-DDE is the dominant contaminant in muscle tissue of the investigated bird speciesDDT accumulation varies among the bird species investigatedA quarter of the investigated birds are at risk of reproductive failure as a result of high p,p’-DDE levels

Human dietary exposure to bisphenol-diglycidyl ethers in China: Comprehensive assessment through a total diet study

Despite the widespread use of bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) in various consumer products as protective plasticizer, studies on human dietary exposure to these compounds are scare. In this study, nine bisphenol diglycidyl ethers (BDGEs) including BADGE, BFDGE, and seven of their derivatives were determined in the Chinese adult population based on composite dietary samples collected from the sixth (2016–2019) China total diet study (TDS). Contamination level of nine BDGEs was determined in 288 composite dietary samples from 24 provinces in China. BADGE·2H2O and BADGE are the most frequently detected and BADGE·2H2O presented the highest mean concentration (2.402 μg/kg). The most contaminated food composite is meats, with a mean ∑9BDGEs of 8.203 μg/kg, followed by aquatic products (4.255 μg/kg), eggs (4.045 μg/kg), and dairy products (3.256 μg/kg). The estimated daily intake (EDI) of ∑9BDGEs based on the mean and 95th percentile concentrations are 121.27 ng/kg bw/day and 249.71 ng/kg bw/day. Meats, eggs, and aquatic products are the main source of dietary exposure. Notably, beverages and water, alcohols were the main contributors of dietary exposure to BADGE and BADGE·2H2O, followed by animal-derived foods. Dietary exposure assessment demonstrated that human dietary BDGEs do not pose risks to general population based on the mean and 95th percentile hazard index with < 1. This is the first comprehensive national dietary exposure assessment of BDGEs in Chinese general population.

Neighborhood-scale ambient NO2 concentrations using TROPOMI NO2 data: Applications for spatially comprehensive exposure assessment

This study estimated long-term average ambient NO2 concentrations using TROPOspheric Monitoring Instrument (TROPOMI) tropospheric NO2 data and land use information at the spatial resolution of 500 m in California for the years 2018–2019. Our satellite-land use regression model demonstrated reasonably high predictive power with cross-validation (CV) R2 = 0.76, mean absolute error (MAE) = 1.95 ppb, and root mean squared error (RMSE) = 2.51 ppb in a comparison between measured and estimated NO2 concentrations. Exploiting the high-resolution NO2 estimates, we further investigated the representativeness of ground NO2 monitors for population exposures and examined the spatial variation of NO2 in relation to parcel-level property data for exposure attributions. The ground NO2 monitors were the most representative of population exposures in Los Angeles and San Diego counties, supported by population-weighted average NO2 concentrations (satellite-derived estimations) similar to arithmetic average NO2 concentrations (ground measurements). On the contrary, the exposure assessment using the ground monitors was the least representative and protective in Humboldt, San Luis Obispo, and Yolo counties with population-weighted average NO2 greater than arithmetic average NO2 by 82.2 % (1.85 ppb), 67.1 % (1.89 ppb), and 58.2 % (2.48 ppb), respectively. In a case study of LA County, we identified comparatively high NO2 concentrations for the property types of food processing facilities and high-density residential complexes (such as high-rise apartments and apartments). This finding provides evidence that these emerging sources may be crucial to mitigate cumulative NO2 exposures and subsequent health risks from a regulatory perspective.