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Despite increasing interest in and use of nanoparticles (NPs), the environmental consequences of using NPs are poorly understood because most relevant studies have not taken the effects of natural coatings on NPs into consideration. The aim of this study was to improve our understanding of the fates of NPs in aquatic systems. The fates of silver NPs (AgNPs) capped with citrate and polyethylene glycol dispersed in ecotoxicological matrices in the presence of environmentally relevant components of natural water (humic substances and extracellular polymeric substances) were investigated. Interactions between AgNPs and natural organic matter were evaluated by ultracentrifugation and electrophoretic mobility measurements to assess AgNP dissolution. Humic substances and extracellular polymeric substances both decreased the dissolution rate. The natural organic matter (humic substances and extracellular polymeric substances) provided conditions in which the medium stabilized the NPs. The dissolution rate depended on the coating type (citrate or polyethylene glycol), dissolved organic carbon concentration, and particle concentration. The presence of algae and Daphnia affected AgNP conversion, demonstrating the value of research that takes environmentally relevant matrices into consideration. The results improve our understanding of the factors that affect the bioavailabilities of AgNPs and therefore improve our ability to evaluate AgNP toxicity. Studies of other NPs using the same strategy will improve our understanding of the fates of nanomaterials in the environment and biota.Highlights• Natural organic matter controls silver nanoparticle environmental dissolution/fate.• Exopolysaccharides and aquatic humic substances both promote AgNP stabilization.• Capping agents (citrate or polyethylene glycol) change the AgNP dissolution rate.• AgNPs behave differently in media containing algae and Daphnia. LESS      Full article

The Minamata disease, first identified in Japan in the 1950s, is caused by severe methylmercury (MeHg) poisoning. To prevent the development of this disease, routine evaluation of MeHg levels in blood samples is crucial. The purpose of this research was to explore the use of derivatization and capillary gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) for the quantitative detection of both organic and inorganic mercury in blood samples. Alkyl mercury in standard solutions was extracted as halide salts in toluene with hydrohalic acid. Fat contents in whole blood samples were removed by methyl isobutyl ketone and hexane using a cysteine/alkaline solution and then organic mercury was extracted as a bromide complex using toluene and cupper chloride solution. The linearity of the response ratio vs. concentration curves (R²) was 0.987 for methylmercury bromide and 0.990 for ethylmercury (EtHg) bromide, over the calibration range of 0.02 ng/mL to 20 ng/mL. The recovery of MeHg and EtHg was 67.1% and 49.3%, respectively. The concentrations of MeHg in whole blood samples determined using GC with an electron capture detector agreed with those determined using GC-NCI-MS, with a correlation coefficient of 0.923. The mean concentration of MeHg in a certified reference material (NMIJ CRM 7402-a) determined using GC-NCI-MS was 0.64 μg/g, comparable with the certified value of 0.58 μg/g. Our study demonstrates a simple and low-cost approach for analyzing mercury in biological samples, although further optimization is required given the relatively low recovery and the concern about the toxicity of methyl isobutyl ketone. LESS      Full article

The health risks posed by atmospheric brominated flame retardants (BFRs) have been widely studied, but there remains a lack of clarity about exposure differences between clear days and haze days. We sampled the total suspended particle (TSP) and gaseous BFRs on clear days in summer, clear days in winter, and haze days in winter in Harbin, China, to investigate the variations in the concentrations and intakes (dermal and inhalation) in the different weather conditions. The concentrations of atmospheric BFRs were highest on haze days in winter (185 pg/m³), followed by clear days in summer (158 pg/m³), and clear days in winter (79.2 pg/m³), and these concentrations were significantly correlated with the concentrations of TSP. The human intake in the different weather conditions followed the pattern of the BFR concentrations, and the human intake of atmospheric BFRs was dominated by inhalation. A comparison of the BFR levels showed that the human intake of gaseous and particulate BFRs varied in the three weather conditions and that the inhalation intake, but not the dermal intake, was influenced under high concentrations of gaseous BFRs with low molecular weight. LESS      Full article

Polycyclic aromatic hydrocarbons (PAHs) in sediment cores from Phayao Lake were investigated in terms of their concentration, distribution, and potential effects on the environment and human health. The concentration of Σ16PAHs ranged from 77.6 to 1251.1 ng g^-1. Additionally, low molecular weight PAHs (two or three fused aromatic rings) were dominant, indicating that the main source of PAHs is the incomplete combustion of organic sources. The toxic equivalent quantities (TEQs) of 16 PAHs varied from 2.67 to 155.09 ng g^-1, with an average of 38.29 ± 46.69 ng g^-1. Furthermore, the TEQs of 9 known carcinogenic PAHs averaged 20.77 ± 30.63 ng g^-1. B[a]P had the highest TEQ, followed by D[a,h]A and B[k]F, with values of 16.93 ± 25.49, 13.89 ± 15.37 and 2.12 ± 3.64, respectively. The RQ_(NCs) of ΣPAHs (RQ_ΣPAHs(NCs)) ranged from 1.65 × 10^-4 to 6.27 × 10^-1 with an average value of 1.18 × 10⁰ ± 1.52 × 10⁰. Moreover, RQ_(NCs) was less than 1 for individual PAHs, indicating a minor risk. However, RQ_(MPCs) was less than 1 for individual PAHs, indicating a moderate risk. The results showed a significant incremental lifetime cancer risk (ILCR) from sediment-bound PAHs with dermal absorption, followed by ingestion and inhalation, as the prevalent route of exposure. The measured ILCR values of all PAHs were less than 10^-6 for both adults and children, which were lower than the baseline value, indicating that each PAH poses a low risk of cancer to humans. This study provides information for control and preventive actions to limit future PAH pollution in Phayao Lake. LESS      Full article

The global push towards a circular economy (CE) has led to increasing efforts to improve resource utilization efficiency, including plastics recycling. However, the presence of additives, especially those that are toxic, complicates plastics recycling in several ways. Without sufficient controls, the spread of hazardous additives via recycling activities represents a significant public health challenge, particularly among developing nations. This study demonstrates evidence of such uncontrolled recycling, based on an investigation of four household flexible PVC product groups available in Thailand. A versatile pyrolysis/thermal desorption gas chromatography-mass spectrometry (Py/TD-GC-MS) method was employed to simultaneously screen 18 target plasticizers in these products. Di-(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DINP) are the most frequently detected primary plasticizers. DEHP is dominant in vinyl boots, flooring sheets, and hoses, while DINP is dominant in cable sheaths, likely due to a spill-over effect from the EU Restriction of Hazardous Substances (RoHS) directive. Chlorinated paraffins (CPs) are secondary plasticizers that are also detected in most samples, except for boots. The other plasticizers detected include other ortho-phthalates and non-phthalates. These results provide insight into combinatory patterns of plasticizer ‘cocktails’, that comprise restricted, as-yet-unrestricted, and non-restricted plasticizers, embedded in the same individual samples, with a maximum of seven plasticizers found in a single cable sheath. These findings indicate the existence of potentially risky recycling practices that target embedded plasticizers to save cost, without due consideration of their inherent toxicity. Proper interventions are necessary to ensure that CE and chemical safety can be synergized. LESS      Full article

Chronic ethylbenzene exposures and attendant potential health risks for United States children and prospective parents were first evaluated under the United States Environmental Protection Agency’s Voluntary Children’s Chemical Evaluation Program. Using updated data and methods, a 2015 reevaluation observed declines in ethylbenzene releases and concentrations in ambient and indoor air. Both assessments identified inhalation as the dominant exposure route and smoking as the greatest contributor, with dietary intake much lower. Children’s exposure concentrations were similar to that of adults, but their intakes were higher. Neither breastfeeding nor toy mouthing was a significant source. This report updates the previous assessments, summarizing current ethylbenzene concentrations in air and foods, exposures during the use of household and consumer products, nationally representative biomonitoring data, including expanded demographic groups, and a new survey of worker exposures in styrene production facilities. General population ethylbenzene exposures appear to have declined for all age groups. The ethylbenzene/styrene chain of commerce contributes an estimated 0.1% to total air emissions and 7%-12% to dietary concentrations. Total estimated ethylbenzene intakes are consistent with biomonitoring data. Lactational transfer is not a significant exposure pathway for breastfed infants. Production workers’ exposure is well below occupational guidelines. Updated exposure estimates for each pathway suitable for potential health risk assessment are proposed. LESS      Full article

Pesticide use is a common practice worldwide, especially in Sub-Saharan African (SSA) countries, where ongoing agriculture intensification and the need for disease vector control make it essential. The population can thus be exposed to variable amounts of pesticides through the diet. Edible insects are a highly regarded food source in SSA. However, they are still mostly harvested from the wild, where chemical applications are not necessarily controlled, representing a major cause of concern for consumers. We investigated residues of legacy (OCPs) and current-use pesticides (CUPs) in selected edible insects commonly consumed in Uganda and Nigeria, and evaluated the eventual health risk for the adult population associated with their consumption. Targeted OCPs were < LOQ in all analysed edible insects, except for hexachlorobenzene (up to 0.87 ng/g dw), while several CUPs were present at notable levels. Cypermethrin showed the highest median concentration (17 ng/g dw), while the Nigerian cricket Brachytrupes membranaceus was the most contaminated sample, with concentrations of aldicarb, propoxur, chlorpyrifos, dichlorvos and paclobutrazol reaching 118 ng/g dw, 327 ng/g dw, 156 ng/g dw, 26 ng/dw, and 14 ng/g dw, respectively. The concentrations of pesticides were generally well below the available maximum residue levels (MRLs), and the dietary risk assessment did not indicate health threats for the adult population. However, we suggest that the monitoring of the chemical safety of edible insects in SSA should be further investigated and insects should be integrated into more extensive dietary studies. LESS      Full article

Per- and polyfluoroalkyl substances, chlorinated paraffins, brominated flame retardants, polychlorinated biphenyls and mirex are regulated under the United Nations Environment Programme’s (UNEP’s) Stockholm Convention on Persistent Organic Pollutants (POPs) intended for the eradication of hazardous contaminants in the environment. There is also a major concern for organophosphate esters and specific alternative or novel brominated flame retardants. To date, no evidence exists that major producers of these chemicals occur on the African continent. They are understood to find their way into African environments through the import of commercial products, in particular products with second-hand value and short lifespans, which may enter waste streams in a relatively shorter period. To further understand the current levels of these selected contaminants in African waste streams, existing documents capturing various African waste stream compartments for the above outlined targeted contaminants were gathered from an exhaustive literature review. Key factors influencing the transfer of contaminants from waste or elevated concentrations of contaminants in African waste streams are associated with the nature and/or sources of contaminants, volume of contaminants or waste in relation to the capacity of treatment plants/landfills, condition or age of treatment plants/landfill geomembrane liner, model adopted for contaminants removal and treatment procedures for collected sludges or leachates. Evidence from the selected studies indicates substantial POP contamination in African landfills and dumpsites, wastewater effluents/sludge and human/biological samples around dumpsites and landfills. Unfortunately, the continent has inadequate infrastructural capacity to adequately handle POP in the waste streams. This review provides recommendations and suggestions for future studies. LESS      Full article

With the recent improvements in high-resolution mass spectrometry (HRMS), retrospective chemical analysis has been increasingly used in environmental sciences. This enables new insights into the chemical content of previously analysed samples with new data analysis methods or new information about emerging contaminants. This study aimed to conduct an in-depth investigation into the chemical content of various indoor dust samples using retrospective analysis. The samples were previously extracted using liquid-solid extraction without clean-up to increase the chemical coverage and thereafter analysed both using liquid chromatography (positive and negative ionisations) and gas chromatography coupled with high-resolution mass spectrometry. A retrospective data processing workflow was conducted in this new study by using both suspect screening analysis and non-target analysis. Among 30 dust samples from four different indoor settings, 298 compounds were tentatively identified with an identification confidence level of ≥ 3. The discussion was conducted on both individual compounds as well as their chemical compound groups and functional uses. Main detected chemical groups were plant natural products (n = 57), personal care products (n = 44), pharmaceuticals (n = 44), food additives (n = 43), plasticisers (n = 43), flame retardants (n = 43), colourants (n = 42) and pesticides (n = 31). Although some detected compounds were already reported for the same samples in our previous study, this retrospective analysis enabled the tentative identification of compounds such as polyethylene glycols, per- and polyfluoroalkyl substances, pesticides, benzotriazoles, benzothiazoles, fragrances, colourants and UV stabilizers. This study showed the usefulness of retrospective analysis on indoor dust samples to further characterise the chemical content, which can help to better estimate the exposure risks of organic contaminants to humans in the indoor environment. LESS      Full article

In this study, five surface water and sediment samples were collected from five different points along the course of the Udu River, Niger Delta, Nigeria, which were near the human population. Water samples were liquid-liquid extracted with dichloromethane in a separatory funnel, while sediment samples were Soxhlet extracted using a mixture of acetone, dichloromethane, and n-hexane. Quantification of polychlorinated biphenyls (PCBs) in the extracts was done using gas chromatography-mass spectrometry. The ecological risk of PCBs was assessed by comparing the determined PCB concentrations with established guideline values, while health risk was evaluated using non-cancer and total cancer risk models. From the results obtained, only one congener (PCB-167) was present in water samples, with concentrations ranging from 20-1860 ng L^-1. For sediment samples, 28 congeners were detected. The concentration of Ʃ₂₈PCBs and the 12 dioxin-like PCBs (dl-PCBs) ranged from 5.34-16.1 and 1.07-5.36 ng g^-1, respectively. The toxicity equivalence values for dl-PCBs varied from 0.0065-0.018. Compared to guideline values for both water and sediment, the PCB concentration obtained in this study does not pose any ecological risk at all except for one sampled point. Similarly, the hazard index values for non-cancer risk evaluation were < 1 at all but one point, while total cancer risk values were between 1 × 10^-6 and 1 × 10^-4 at all but one sampling point, indicating no potential risk of developing cancer associated with PCBs in water and sediments of the Udu River. LESS      Full article

The occurrence and risks of polychlorinated biphenyls (PCBs) in water, sediment, and fish from the Wupa River, Nigeria, were assessed in this study. Water, sediment, and fish were collected from five locations in the Wupa River in November 2019. After extraction with dichloromethane, hexane, and acetone, the PCBs were determined using gas chromatography equipped with a quadrupole mass spectrometer. The hazard index and total cancer risk models were used for risk evaluation of the detected PCBs. The results of this study show that the ∑28 PCB concentrations in the water, sediment, and fish ranged from 0.04-11.42 ng/L, 5032-10132 ng/g, and 64-4254 ng/g, respectively. The hazard index values for children and adults were generally > 1, suggesting a potential non-carcinogenic risk for humans exposed to PCBs from the river. However, the total cancer risk values were above 1 × 10^-6 and indicated that there is a carcinogenic risk for humans exposed to the PCBs from Wupa River. LESS      Full article

The objective of the current study was to calculate the deposited dose rate in the human respiratory tract arising from particle number (PN) and particle mass (PM) measurements. A main objective was the investigation of deposition pattern and characteristics of the two metrics in the human respiratory tract. The dose rate was estimated for residents at a suburban background location (Chania, Greece). The total dose rate showed two peaks, one in the morning (1.6 × 10⁹ particles/h at 7:00-8:00) and the other one at night (2.1 × 10⁹ particles/h at 21:00-22:00), during the warm period, while the cold period showed two peaks, morning (2.0 × 10⁹ particles/h at 9:00-10:00) and afternoon (3.6 × 10⁹ particles/h at 18:00-19:00). The peaks during the warm period were associated with traffic emissions, whereas the peaks during the cold period were associated with both heating and traffic emissions. A higher dose rate of PN₁₀ was found in the alveolar region while for PM₁₀ it was found in the extrathoracic region. These findings are linked with increased contribution of ultrafine and coarse particles to PN₁₀ (65%-78% and 54%-62% for cold and warm periods, respectively) and PM₁₀ (63% and 55% for cold and warm periods, respectively) concentrations, respectively. The current study showed the importance to use both number and mass aerosol metrics for determining the human exposure and regional dose and their related health effects. The novelty of the current study is the simultaneous measurements of the two particles metrics and the full particle size distributions to make accurate estimates of regional deposited dose. LESS      Full article

Assessing chemical exposure in home and personal care products (HPCPs) represents an important data need. Key challenges to the assessment are related to limited knowledge in quantifying and characterizing the weight-fraction inclusion level and functionality of chemicals in HPCPs. Publicly available tools have been developed to address these challenges, such as the Chemical and Products database (CPDat). This study aims to evaluate the relative performance of CPDat by comparing estimates of weight-fraction inclusion level and functionality to other relevant data sources. Specifically, estimates obtained from CPDat are evaluated and compared with estimates obtained from marketing analytic data, using Euromonitor Passport for 31 commonly used chemicals found in HPCPs. The results obtained from this exercise suggest relatively good agreement between each of the methods for 10 chemicals (ρ = 0.92; P-value =0.02). When considering all 31 chemical ingredients, however, the correlation observed is generally poor (ρ = 0.46; P-value = 0.1), which is attributed to differences in how the underlying data are obtained for each method. With an emphasis on obtaining data based on mining datasheets for individual products, the application of CPDat is suggested to be useful for higher tiers of assessment, with data obtained from marketing analytics providing valuable input to exposure-based screening models. The insight gained from this study can be used to help guide the appropriate use of data obtained from different sources within a tiered exposure assessment. LESS      Full article

The occurrence and behavior of dechlorane plus (DP), an additive chlorinated flame retardant, have been intensively studied since it was identified in 2006. The commercial products of DP are a mixture of two stereoisomers: syn-DP and anti-DP. Stereoselective bioaccumulation of DP isomers in biota was reported in field monitoring and laboratory experiments. This review summarizes stereoselective bioaccumulation of DP in biota samples and provides the potential mechanisms for this stereoselective bioaccumulation. Stereoselective enrichment of syn-DP was widely observed in fish, whereas selective enrichment of anti-DP was mainly found in some birds. This species-specific stereoselective enrichment of DP might reflect that two different types of DP isomer fractionation occurred in bioaccumulation between ectotherms and endotherms. Anti-DP is more readily metabolized through biotransformation in all animals. However, a preferential excretion of anti-DP in fish and syn-DP in birds was observed based on the available data. Both processes determine the DP isomer fractionation in bioaccumulation. A direct comparison in DP composition between biological samples and commercial products was conducted for most studies to determine the occurrence of stereoselective DP enrichment, which may lead to underestimating the potential stereoselective enrichment of DP in organisms. The factors which affected the DP isomer composition in organisms included the tissues or organs used, DP concentration, organisms’ trophic levels occupied, and sex2022/7/6. Inconsistent results were obtained considering the effects of these influence factors. The underlying cause of these inconsistent results is unclear based on present data. Further research on DP biotransformation and interactions between DP and biomacromolecule is needed. LESS      Full article

Dust is a widely-used matrix for estimating human exposure to chemicals or as a screening tool for the identification of indoor chemicals of concern. As dust sampling became more common in exposure assessment, techniques used in processing soil have been adapted to dust samples, and separation of dust particles by sieving is common practice. However, there are no defined pore sizes, which results in inconsistent or difficult data interpretation and exposure estimates. Moreover, dust consists of more particle types than soil, particularly fibers, which behave differently during the sieving process. In this study, composite samples from seven microenvironments (homes, apartments, kindergartens, schools, public spaces, offices, and cars) were used to investigate the impact of the separation of dust by sieving on the observed chemical distributions. Dust was sieved to four particle size fractions (1-2 mm, 0.5-1 mm, 0.25-0.5 mm, and < 0.25 mm) and each fraction was analyzed for organic carbon content and polycyclic aromatic hydrocarbons (PAHs), and images of dust samples were taken by optical microscope. We identified irregular distributions across size fractions for carbon and PAHs as well as for fibrous particles. Based on the combination of chemical analyses and microscopy, we recommend careful consideration of pre-processing of dust samples to limit bias in dust exposure assessments, and sieving should be used only when necessary. LESS      Full article

This paper presents data obtained from concurrently deployed polyurethane foam disk passive samplers in Kuwait, Turkey, Lebanon, Saudi Arabia, and Oman between January and October 2018. The study’s main goal was to initiate a passive air sampling network across the Middle East to generate comparable data, which will help report obligations of the various countries and be used in protocol discussions. The ∑₂₄OCP concentrations were highest in the samples collected from Kartaba in Lebanon (7780 pg·m^-3), and the lowest concentration was recorded at the BUTAL site in the Bursa province of Turkey (7.27 pg·m^-3). The mean ambient ∑₂₄OCP concentrations on a country-specific basis over consecutive sampling campaigns were: Lebanon (1680 pg·m^-3) > Bursa (Turkey) (78.7 pg·m^-3) > Oman (55 pg·m^-3) > Kuwait (42 pg·m^-3) > Jeddah, Saudi Arabia (19.1 pg·m^-3). The results show no cancer risk due to inhalation of organochlorine pesticides (OCPs) in ambient air. This study provides the first reliable measurements of the spatial variability in the atmospheric concentrations of OCPs across several Middle Eastern countries, providing a baseline for assessing time trends in air, one of the core matrices for the effectiveness evaluation of the Stockholm Convention on Persistent Organic Pollutants. LESS      Full article

While it is recognised that humans are constantly exposed to plastics, there are limitations in understanding the extent of this exposure, particularly dietary exposure. This lack of information is partly due to challenges with the analysis of complicated matrices. This study aimed to assess the impact of medium to high lipid content (> 3%) food samples on the accurate quantification of polyethylene (PE), using pyrolysis-gas chromatography mass spectrometry, and develop an alternative sample processing strategy. Analysis of saturated, monounsaturated and polyunsaturated fats was demonstrated to form the same pyrolysis products as PE, producing a significant interference hindering quantification. An extraction protocol was developed that involves enzyme digestion to break the lipids into smaller chain fatty acids, removal of these interferences with pressurised liquid extraction washes, before a final extraction of the PE by pressurised liquid extraction. This new method was validated through the analysis of three medium- to high-fat content foods: cow’s milk, eggs and lamb meat, where PE recoveries were acceptable (104% to 127%). Method detection limits were also significantly reduced from 1.9 to 0.05 µg/injection (380 to 10 µg/g) with the new protocol, through the removal of matrix background. PE traces were observed in the three food matrices of 72-240 µg/g, significantly reduced as compared to samples extracted with the old method where concentrations of 12-32 mg/g were calculated, demonstrating the potential for overestimation of dietary exposure. Finally, a simple protocol is reported for future studies to (i) determine if an interference is present and (ii) sample processing methods to remove identified interferences. LESS      Full article

Organophosphate ester (OPE) concentrations and distributions in 15 tree bark and 59 human hair samples from Weifang and Yantai (Shandong Province, China) were determined. The total OPE concentrations in tree bark samples from Weifang and Yantai were 16.5 ng/g-78.5 ng/g and 9.34 ng/g-98.6 ng/g dry weight (dw), respectively. The total OPE concentrations in hair samples from Weifang and Yantai were 54.2 ng/g dw-8450 ng/g dw and 7.26 ng/g dw -13,900 ng/g dw, respectively. Chlorinated OPEs were dominant in the tree bark samples from both Weifang and Yantai. Tris(2-chloroethyl)phosphate (TCEP) was the dominant OPE in the hair samples from residents of Weifang and Yantai. Attention should be paid to human exposure to TCEP, which is carcinogenic. The OPE concentrations in human hair were highest for the < 20 years age group. The OPE patterns between the two cities were similar for both tree bark and hair, but the OPE patterns in the tree bark and hair samples from the same place were significantly different. This indicates that the outdoor atmosphere may not be the main source of OPEs in human hair. LESS      Full article

Aim: This study investigated hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) concentrations in indoor dust from houses, offices, and cars and estimated toddler and adult exposure to HBCDD and TBBPA through dust ingestion.Methods: The concentrations of HBCDD and TBBPA were measured in 47 indoor dust samples collected from the Bangkok metropolitan area, Thailand. All samples were analyzed for HBCDD and TBBPA using LC-MS/MS. The estimated daily intake (EDI) through dust ingestion was calculated from the median and 95th percentile concentrations of HBCDD and TBBPA.Results: HBCDD was detected in 47% of samples, and TBBPA was detected in all samples. The median concentrations of HBCDD were 6.7 ng g^-1, <0.7 ng g^-1, and <0.7 ng g^-1 in cars, houses, and offices, respectively. The isomer composition of ∑HBCDD in dust was: α-HBCDD (40%-54%), γ-HBCDD (19%-40%), and β-HBCDD (17%-28%). In contrast, TBBPA was observed at higher concentrations, with median values of 674, 67, and 22 ng g^-1 in offices, houses, and cars, respectively. Under a median exposure scenario, toddlers were exposed to 0.05 ng kg^-1 bw day^-1 for HBCDD and 0.25 ng kg^-1 bw day^-1 for TBBPA, with adults exposed to 0.01 and 0.06 ng kg^-1 bw day^-1 for HBCDD and TBBPA respectively.Conclusion: Concentrations of HBCDD in dust from Thai cars, homes, and offices are lower than those of TBBPA following the listing of HBCDD in the Stockholm Convention on Persistent Organic Pollutants and limited use of HBCDD in Thailand in applications such as building insulation foam. Concentrations of TBBPA in office dust significantly exceeded (P < 0.05) those in house and car dust owing to the greater number of electronic appliances and poor natural ventilation in offices. EDIs for Thai toddlers exceeded those of adults under both median and high-end exposure scenarios. However, EDIs of HBCDD and TBBPA for the general Thai population were below the corresponding oral reference dose guidelines. LESS      Full article

Polychlorinated naphthalenes (PCNs) were listed as Persistent organic pollutants in the Stockholm Convention, in May 2015, because of their adverse health and environmental effects. PCNs production began in the early 1900s when they were used extensively in several consumer goods as fire retardants. However, because of their health and environmental implications, the production and use of PCNs chemicals were voluntarily banned in many countries in the 1970s and 1980s. However, PCNs are still detected in different environmental samples including air, water, sediments, soil, indoor dust, biota, consumer products, human diet, blood and serum today, as a result of their historical use and unintentional production. Thus, PCNs can be released into the environment throughout their life cycle. It becomes, therefore, crucial to monitor them in different environmental compartments. To date, about 163 reports on PCNs levels in several matrices have been published in different parts of the world. It was reported that toxic PCNs such as chloronaphthalenes 66, 67 and 73 are prevalent in most samples; thus, there is a need to continuously monitor these congeners in our environment. However, there are sparse studies related to PCNs levels, not only in consumer products, leachates and sediment samples from landfill sites in Africa but also in other matrices, leaving a huge research gap that must be prioritized. To date, only about 3 studies on PCNs have been published in Africa, bearing in mind that there is no documented evidence of any known production of PCNs in the continent. Thus, a wide research gap in PCNs studies still exists in Africa. There is an urgent need, therefore, to conduct studies and establish robust PCNs inventories in Africa. The present review examines the existing knowledge on PCNs levels and trends in Africa, and identifies research gaps that ought to be addressed so that the scale of PCNs distribution in the global environment can be known. LESS      Full article

This paper describes the validation of a method for the simultaneous analysis of short-, medium-, and long-chained chlorinated paraffins (SCCPs, MCCPs, and LCCPs, respectively) in indoor dust by ultrasonic extraction and liquid chromatography quadrupole time-of-flight high-resolution mass spectrometry (LC-QTOF-HRMS). A series of spike and recovery experiments (n = 54) were conducted using CPs with varying carbon-chain lengths, chlorination degree, and concentrations. Technical standard mixtures of the SCCPs, MCCPs, and LCCPs were used to quantify spiking experiments by two commonly used calibration procedures: pattern deconvolution and chlorine-content calibration. The results quantified by pattern deconvolution meet the acceptability limits of the European Union Reference Laboratory (EURL) for all tests with trueness ranging from 72% to 141% and good precision represented by coefficients of variation (CVs) less than 15% in all experiments. The chlorine-content calibration also performed well overall, but on average overestimated concentrations for SCCPs and MCCPs by 32% and 25%, respectively, and did not meet the EURL’s trueness limits in all cases. CVs were below 18% for all results derived from the chlorine-content quantification. The final method was successfully applied to indoor dust samples from offices (n = 4), homes (n = 3), and a vehicle (n = 1) from Melbourne, Australia, with SCCPs (C_10-13), MCCPs (C_14-17), and LCCPs (C_18-20) detected in all samples, up to 100, 240 and 190 μg/g, respectively. A preliminary human exposure assessment suggested that CP intake via dust may constitute a major pathway of exposure for populations in Melbourne, Australia. LESS      Full article

Concentrations of 19 organophosphate esters (OPEs) were determined in dust samples collected from house and car indoor microenvironments in three Colombian cities. ∑OPE concentrations ranged from 1.31 to 599 μg/g. Mean concentrations of dust homes were 82.6, 48.3, and 46.7 μg/g for Cartagena, Bogotá, and Medellín, respectively. The pollution inside cars was somewhat higher than in houses, with a mean value of 231 μg/g. Sixteen compounds were detected, being TPHP, DCP, TEP, and TCEP the most frequently detected. As for OPEs with higher levels in houses, we found (mean ± SD) 35.2 ± 37.1 μg/g for TDCIPP in Cartagena, 35.6 ± 80.2 μg/g for TPHP in Cartagena, 15.9 ± 31.4 μg/g for DCP in Cartagena, 35.7 ± 19.1 μg/g for TBOEP in Bogotá, 15.7 ± 14.8 μg/g for 4IPPDPP in Medellín, and 17.5 ± 22.9 μg/g for TCEP in Cartagena, while the highest OPE value found in cars was 176 ± 144 μg/g for TDCIPP. The estimated daily intake (EDI) of OPEs through dust ingestion ranged from 0.001 ng/kg bw/day for adults to 110 ng/kg bw/day for toddlers, while dermal absorption ranged from 0.02 ng/kg bw/day for adults to 42.7 ng/kg bw/day for infants. Overall, the EDIs of dust ingestion were three times greater than those of dust dermal absorption. The estimated EDIs were several orders of magnitude below the corresponding reference doses. However, the incremental lifetime cancer risk (ILCR) for TCEP ranged from 1.1 × 10^-5 for infants in Bogotá to 4.3 × 10^-4 for adults in Cartagena, while ILCR for TEHP ranged from 8.8 × 10^-7 for infants in Bogotá to 1.1 × 10^-5 for adults in Bogotá. These estimated ILCRs were higher than the safe limit value of 1 × 10^-6 and showed that these populations are exposed to moderate cancer risk. LESS      Full article

Aim: Most of the carcinogenic pollutants coming from tobacco smoking or other combustion processes tend to accumulate in settled house dust (SHD) over time. This study evaluated the load of these pollutants in smokers and non-smokers’ houses from relatively fresh SHD collected in five different districts on the island of Malta.Methods: An improved, efficient extraction method to obtain three fractions from a 200 mg of SHD was developed. It was validated for the analysis of nicotine and polycyclic aromatic hydrocarbons (PAH) by GC-MS/MS and nicotelline and TSNA by LC-MS/MS. Kruskal-Wallis H tests were used to evaluate differences across districts, while a Mann-Whitney U test was used to check differences between smokers and non-smokers’ houses. Diagnostic ratios were used to evaluate the carcinogenicity of PAH in SHD in Malta.Results: For all analytes, no statistical difference was observed across different districts, but, in smokers’ houses, 97.9% of the total concentration of all target analytes found in SHD is nicotine, 0.1% is TSNA, and 2.0% is PAH. In non-smokers’ houses, nicotine represents 16.8% of the load, while 0.4% and 82.8% are TSNA and PAH, respectively. The carcinogenicity of the PAH mixture in Maltese SHD, expressed as the mean benzo(a)pyrene equivalent (BaP_eq) is 371 ng/g.Conclusion: Indoor activities, ventilation practices, and infiltration of outdoor pollutants contribute to a complex SHD composition. Although the BaP_eq is on the lower end of carcinogenicity, the effects of a mixture including tobacco-related potent carcinogens in SHD are largely unknown. In view of indoor, continuous exposure to SHD through several pathways, further research is warranted. LESS      Full article

Microplastics (MPs) are ubiquitous environmental contaminants of considerable persistence and have been a global concern for the past decade. Recently, atmospheric MPs have gained attention. The presence of MPs in the air has been reported from different regions and in air masses over water bodies, demonstrating MPs’ capability of long-range transport and wide spatial distribution away from their source of origin. This review of atmospheric MPs raises questions about the validity and legitimacy of approaches adopted for assessing MP in indoor and outdoor aerosols. The review also provides insight into active and passive sampling techniques and draws attention to the use of the data produced. MP abundance in the atmosphere varies widely among studies due to the disparities in methods employed and the heterogeneity in reporting, making comparisons across spatio-temporal domains infructuous. This review also highlights the paucity of data on atmospheric MPs, and the eminent need to harmonize the methodology for generating a useful comparable dataset that can be used for human health risk assessments. LESS      Full article

This study compared the concentration of persistent organic pollutants (POPs) in air derived from polyurethane-based passive samplers to those of hair samples collected from humans and sheep. Human scalp hair samples were obtained from 24 healthy individuals and ten sheep (Ovis aries) during indoor and outdoor polyurethane foam plug ambient sampling. The samples were analyzed for polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs). ∑PBDE concentrations ranged 0.6-50 ng·g^-1 (mean, 18.6 ± 13 ng·g^-1) for humans and 0.6-1.4 ng·g^-1 (mean, 1.1 ± 0.25 ng·g^-1) for sheep. The ∑PAH concentrations were log-normally distributed in human hair ranging 98-2529 ng·g^-1 (mean, 460 ± 538 ng·g^-1), whereas concentrations for sheep hair samples ranged 168-526 ng·g^-1 (mean, 334 ± 117 ng·g^-1). Strong correlations (P-values < 0.01) were found between concentrations of PAHs and PBDEs in human and sheep hair with concentrations measured in indoor and outdoor air, respectively. Evidence generated from this preliminary study suggests that hair might be used for the environmental monitoring of POPs in remote sites to provide a first-order estimate of ambient levels. Further studies are required to understand the uptake profiles and validate the use of hair as a sampling medium for POPs in ambient air. LESS      Full article

Purpose: We aimed to determine the amount of some toxic elements in three organs of Hilsa shad, focusing on the possible exposure to human health through Hilsa consumption. This study was designed to determine the concentration of seven toxic trace elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) in three distinct organs (n = 21) (muscle, liver, and gills) of Hilsa shad (Tenualosa ilisha) fish collected from the Bangladeshi coastal area. The samples were digested following a microwave digestion. Inductively coupled plasma mass spectrometer was used as analytical instrument. Estimated daily intakes (EDI) and target cancer risk (TR) were used to evaluate carcinogenic and non-carcinogenic risk.Results: The mean concentrations (mg/kg-wet weight) of toxic elements in different organs of T. ilisha were determined as follows: in muscle, As (4.05), Cd (0.09), Cr (0.12), Cu (0.77), Ni (0.26), Pb (0.20), and Zn (10.64); in liver, As (2.83), Cd (0.84), Cr (0.18), Cu (6.17), Ni (0.55), Pb (0.23), and Zn (30.16) and in gills, As (3.45), Cd (0.05), Cr (0.08), Cu (1.06), Ni (0.51), Pb (0.78), and Zn (35.21). The liver showed higher concentrations of most elements than that of muscle except for As. Concentration of As, Cd, and Pb in the fish were found above the food safety guidelines, while other trace element concentrations were below the permissible range for human consumption. According to EDI and TR values, there were carcinogenic and non-carcinogenic risks from exposure to total As concentration from Hilsa fish consumption.Conclusion: This study suggests that the toxic trace elements contamination levels in Hilsa fish from Bangladesh’s coastal area need to be monitored on a systematic and regular basis to ensure the safety of this food item for human consumption. LESS      Full article

Aim: The aim of this study was to determine the presence, concentrations, dietary intake, and risk of residues of neonicotinoids (NEO) and insect growth regulators (IGR) in commercially available honey in South Africa.Methods: Sample preparation for honey was based on the “dilute and shoot” principle, followed by analysis using an internally validated ultra-high-performance liquid chromatographic coupled to tandem mass spectrometric method. Estimated daily intake and acute and chronic hazard quotients were determined to measure human exposure and health risk to NEO and IGR as well as the risk posed to honeybee.Results: NEO and IGR were detected in 50% and 21% of the 115 honey samples, respectively. The average concentration ranged 0.062-6.50 µgkg^-1 and 0.479-1.644 µgkg^-1 for NEO and IGR, respectively. While acetamiprid was the most detected (24.35%) NEO, imidacloprid presented the highest concentration (16.945 µg kg^-1) in a sample. IGR co-occurred at variable concentrations with NEO in honey samples. The estimated daily intakes (EDI) of NEO and IGR ranged from 9.35 × 10^-7 to 4.93 × 10^-6 mg kg^-1 bwd^-1. The chronic hazard quotient (HQc) and acute hazard quotient (HQa) for NEO and IGR were considerably < 1, indicating negligible risk to human health and honeybee population.Conclusion: A UHPLC-MS/MS method was validated for the simultaneous determination of neonicotinoids and insect growth regulators in honey. Overall, the result of the present study confirms the widespread occurrence of NEO and IGR in honey consumed in South Africa. The EDIs, HQc, and HQa indicate that exposure to all target NEO and IGR via honey consumption constitutes negligible human health risk; however, the consequences of multiple routes of exposure to NEO and IGR cannot be overemphasized. LESS      Full article

Aim: The elucidation of temporal trends in human exposure to polychlorinated biphenyls (PCBs) and 17 polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) since the previous Irish human milk surveys and to evaluate the impacts of legislative bans and restrictions on human exposure to these compounds.Methods: Concentrations of PCBs and 17 PCDD/Fs were measured in 16 pools of human milk collected from 92 Irish primiparas participating in the Irish EPA-funded ELEVATE project between October 2016 and April 2018, using Gas-Chromatography coupled with Mass spectrometry.Results: The geometric mean upper bound concentration of 16 pooled human milk samples [PCDD/Fs + dioxin-like (dl)-PCB TEQ; 4.5 ng kg^-1 lipid weight] are on the lower end of those reported internationally. WHO-TEQ PCDD/Fs + dl-PCB are significantly lower (P < 0.005) compared to those reported in the previous Irish human milk studies in 2010 and 2002.Conclusion: Detected concentrations in this study are comparable to those reported for less industrialised countries in the last WHO/UNEP global surveys for PCDD/Fs. This downward temporal trend likely reflects the impact of regulatory bans and restrictions on the emissions of dioxins and PCBs. While mean upper bound WHO PCDD/F PCB TEQ concentrations are lower than those estimated by EFSA to be associated with adverse health effects in children age 9, maximum upper bound concentrations do exceed EFSA reference concentrations. While the positive health benefits of breastfeeding to both mother and child significantly outweigh potential adverse health effects at reported concentrations, continued action to reduce human body burdens of dioxins and PCBs is required. LESS      Full article