Halogenated flame retardants in home-produced eggs from an electronic waste recycling region in South China: levels, composition profiles, and human dietary exposure assessment

From environment to free-range chickens: Broad exposure to short- and medium-chain chlorinated paraffins in rural Tibetan Plateau, China

Chlorinated paraffins (CPs) are widely employed in various consumer products. Rapid socioeconomic development drives the elevation of CPs contamination by increasing the usage of modern lifestyle products, but limited information exists about their occurrence in remote rural areas. In this study, the occurrence, and profiles of short- and medium-chain CPs (SCCPs and MCCPs) in soils, plants, chicken feeds, eggs, and free-range chicken tissues in the rural Tibetan Plateau were investigated. The median concentrations of SCCPs and MCCPs were 108 and 141 ng/g dry weight (dw) in soils, 1.76 × 103 and 1.16 × 103 ng/g dw in plants, 43.6 and 24.3 ng/g dw in chicken feeds, 299 and 251 ng/g lipid weight in free-range chicken eggs, and 182 -3.45 × 103 and 396 -7.75 × 103 ng/g lipid weight in chicken tissues, respectively. Correlation analysis demonstrated that soil was the primary source of CPs, and free-range chicken eggs were effective bioindicators for SCCPs and MCCPs contamination. Tissue distribution showed that SCCPs and MCCPs were highly accumulated in chicken tissues that local resident preferred to consume (such as muscle and stomach). Our findings lay the foundations for further evaluation of the potential risks of CPs on the ecosystem and human health in remote rural areas.

PBDEs and dechlorane plus contamination in community e-waste recycling: Environmental and health implications in Northeastern Thailand

Electronic waste (e-waste) poses significant environmental and health risks in Thailand due to both domestic production and international imports. A notable portion of this waste is processed in small-scale, community-based workshops, often located in poorer regions, where safety regulations are improperly enforced or entirely ignored. This study focuses on the Kalasin province in Northern Thailand, a region with numerous such workshops, where no comprehensive analysis of exposure to polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) has been conducted. The study's objective was to quantify these toxic substances in environmental and biological samples to assess its contamination and human health risks. Environmental samples, including soil, dust, sediment, ash, eggs, crabs, snails, fish, and rice, were collected from e-waste processing sites and compared with control areas. Blood samples from e-waste workers and a control group were also analysed. Gas chromatography coupled with mass spectrometry operated in negative ion chemical ionization (GC-NCI-MS) was used to quantify PBDEs and DP isomers. Results showed significantly higher concentrations of these toxic compounds in e-waste sites compared to control areas. E-waste workers also had elevated levels of these substances in their blood, suggesting exposure through contaminated dust and food. These findings underscore the severe environmental contamination and health risks associated with improper e-waste management, highlighting the urgent need for regulatory measures and improved recycling practices to safeguard both environmental and public health.

Remarkable Contamination of Short- and Medium-Chain Chlorinated Paraffins in Free-Range Chicken Eggs from Rural Tibetan Plateau

Rapid social-economic development introduces modern lifestyles into rural areas, not only bringing numerous modern products but also new pollutants, such as chlorinated paraffins (CPs). The rural Tibetan Plateau has limited industrial activities and is a unique place to investigate this issue. Herein we collected 90 free-range chicken egg pool samples across the rural Tibetan Plateau to evaluate the pollution status of CPs. Meanwhile, CPs in related soils, free-range chicken eggs from Jiangxi, and farmed eggs from markets were also analyzed. The median concentrations of SCCPs (159 ng g-1 wet weight (ww)) and MCCPs (1390 ng g-1 ww) in Tibetan free-range chicken eggs were comparable to those from Jiangxi (259 and 938 ng g-1 ww) and significantly higher than those in farmed eggs (22.0 and 81.7 ng g-1 ww). In the rural Tibetan Plateau, the median EDI of CPs via egg consumption by adults and children were estimated to be 81.6 and 220.2 ng kg-1 bw day-1 for SCCPs and 483.4 and 1291 ng kg-1 bw day-1 for MCCPs, respectively. MCCPs might pose potential health risks for both adults and children in the worst scenario. Our study demonstrates that new pollutants should not be ignored and need further attention in remote rural areas.

Fragmentation Pathway of Organophosphorus Flame Retardants by Liquid Chromatography-Orbitrap-Based High-Resolution Mass Spectrometry

Organophosphorus flame retardants (OPFRs) have been widely used in polymeric materials owing to their flame retardant and plasticizing effects. Investigating the fragmentation pathway of OPFRs is of great necessity for further discovering and identifying novel pollutants using orbitrap-based high-resolution mass spectrometry (HRMS). A total of 25 OPFRs, including alkyl, halogenated, and aromatic types, were analyzed in this study. The fragmentation pathways of the OPFRs were investigated using orbitrap-based HRMS with high-energy collision dissociation (HCD) in positive mode. The major fragmentation pathways for the three types of OPFRs are greatly affected by the substituents. In detail, the alkyl and halogenated OPFRs underwent three McLafferty hydrogen rearrangements, wherein the substituents were gradually cleaved to form the structurally stable [H4PO4]+ (m/z = 98.9845) ions. In contrast, the aromatic OPFRs would cleave not only the C-O bond but also the P-O bond, depending on the substituents, to form fragment ions such as [C6H7O]+ (m/z = 95.0495) or [C7H7]+ (m/z = 91.0530), among others. Using HRMS improved the accuracy of fragment ion identification, and the pathway became more evident. These fragmentation laws can provide identification information in pollutant screening work and theoretical references for the structural characterization of compounds with diverse substituent structures.

Update of the risk assessment of polybrominated diphenyl ethers (PBDEs) in food

The European Commission asked EFSA to update its 2011 risk assessment on polybrominated diphenyl ethers (PBDEs) in food, focusing on 10 congeners: BDE-28, -47, -49, -99, -100, -138, -153, -154, -183 and ‑209. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour and reproductive/developmental effects are the critical effects in rodent studies. For four congeners (BDE-47, -99, -153, -209) the Panel derived Reference Points, i.e. benchmark doses and corresponding lower 95% confidence limits (BMDLs), for endpoint-specific benchmark responses. Since repeated exposure to PBDEs results in accumulation of these chemicals in the body, the Panel estimated the body burden at the BMDL in rodents, and the chronic intake that would lead to the same body burden in humans. For the remaining six congeners no studies were available to identify Reference Points. The Panel concluded that there is scientific basis for inclusion of all 10 congeners in a common assessment group and performed a combined risk assessment. The Panel concluded that the combined margin of exposure (MOET) approach was the most appropriate risk metric and applied a tiered approach to the risk characterisation. Over 84,000 analytical results for the 10 congeners in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary Lower Bound exposure to PBDEs were meat and meat products and fish and seafood. Taking into account the uncertainties affecting the assessment, the Panel concluded that it is likely that current dietary exposure to PBDEs in the European population raises a health concern.

New brominated flame retardant decabromodiphenyl ethane (DBDPE) in water sediments: A review of contamination characteristics, exposure pathways, ecotoxicological effects and health risks

As an alternative to polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE) has become one of the most important new brominated flame retardants (NBFRs). However, little is known about whether this emerging contaminant may has an environmental fate similar to PBDEs. Sediments are the main sink for DBDPE in the aqueous phase. Worldwide concentration data, since it was first found in sediments to date, have been collated, and the following conclusions have been drawn. (1) DBDPE concentrations in sediments have increased rapidly, often with a higher risk of contamination in source discharge areas. Compared with other countries, DBDPE contamination in China is more severe, especially in Guangdong Province, which is closely related to its being an e-waste dismantling area. (2) The amount of DBDPE in surface sediments has exceeded that of legacy brominated flame retardants (BFRs), and data recorded in sediment cores also corroborate that DBDPE is replacing decabromodiphenyl ether (BDE-209) as one of the most dominant NBFRs in the environment. (3) The exposure pathways of DBDPE include dietary intake, air or indoor dust intake, cutaneous absorption and endogenous exposure. For sediments, dietary exposure and endogenous exposure pathways need to be considered. Sediment DBDPE can enter the human body through bioenrichment such as contaminated seafood and the food chain. (4) DBDPE can exhibit neurotoxicity, thyrotoxicity, reproductive and developmental toxicity, hepatotoxicity and oxidative stress in organisms. Long-term DBDPE exposure may increase hyperthyroidism risk and inhibit normal cells activity. This review focuses on the distribution characteristics and exposure risks of DBDPE in global water sediments, providing a strong reference for environmental management and related legal policy formulation. The next steps are to focus on continuous source monitoring, process control and sediment clean-up of DBDPE. The development of sustainable water management options for waste microplastics (MPs) and e-waste spiked with DBDPE is a priority.

Contamination characteristics and potential health risk of brominated flame retardants in paddy soils and rice plants around a typical e-waste recycling site in south China

Brominated flame retardants (BFRs) are widely used in various productions. As typical BFRs, polybrominated diphenyl ethers (PBDEs) are prohibited because of their toxicity and persistence. Some of the alternatives to PBDEs, new brominated flame retardants (NBFRs), have also been found in the environment and some have assigned hazardous properties and were categorized as persistent. In this study, a typical e-waste dismantling area was chosen as the study area, and the soil and rice samples were collected from the paddy fields around the circular economy park in Guiyu, China. The contaminations of PBDEs and NBFRs in soils and rice plants were detected, and the health risks associated with consumption and exposure to the environment were calculated as well. The concentrations of ∑PBDEs and ∑NBFRs in soil ranged from 283 to 928 μg/kg and 54.7-437 μg/kg, respectively. In rice plants, the majority of BFRs were concentrated in the following order: root > leaf > stem > grain. Additionally, only the PBT exhibited a stronger bioaccumulation ability in rice with the bioconcentration factors more than 1.00. The results of the health quotient calculation shown that BDE-47 might have an impact on people's health that only the HQ of BDE-47 in the soil was higher than 1.00, while there had no significant health risk in grain of BFRs. We believe that our work could assist researchers in investigating and revealing the human health effects of BFRs in soil and rice.

Chlorinated paraffins and dechloranes in free-range chicken eggs and soil around waste disposal sites in Tanzania

Electronic waste is a source of both legacy and emerging flame retardants to the environment, especially in regions where sufficient waste handling systems are lacking. In the present study, we quantified the occurrence of short- and medium chain chlorinated paraffins (SCCPs and MCCPs) and dechloranes in household chicken (Gallus domesticus) eggs and soil collected near waste disposal sites on Zanzibar and the Tanzanian mainland. Sampling locations included an e-waste facility and the active dumpsite of Dar es Salaam, a historical dumpsite in Dar es Salaam, and an informal dumpsite on Zanzibar. We compared concentrations and contaminant profiles between soil and eggs, as free-range chickens ingest a considerable amount of soil during foraging, with potential for maternal transfer to the eggs. We found no correlation between soil and egg concentrations or patterns of dechloranes or CPs. CPs with shorter chain lengths and higher chlorination degree were associated with soil, while longer chain lengths and lower chlorination degree were associated with eggs. MCCPs dominated the CP profile in eggs, with median concentrations ranging from 500 to 900 ng/g lipid weight (lw) among locations. SCCP concentrations in eggs ranged from below the detection limit (LOD) to 370 ng/g lw. Dechlorane Plus was the dominating dechlorane compound in all egg samples, with median concentrations ranging from 0.5 to 2.8 ng/g lw. SCCPs dominated in the soil samples (400-21300 ng/g soil organic matter, SOM), except at the official dumpsite where MCCPs were highest (65000 ng/g SOM). Concentrations of dechloranes in soil ranged from below LOD to 240 ng/g SOM, and the dominating compounds were Dechlorane Plus and Dechlorane 603. Risk assessment of CP levels gave margins of exposure (MOE) close to or below 1000 for SCCPs at one location.

Presence of novel and legacy flame retardants and other pollutants in an e-waste site in China and associated risks

Electrical and Electronic Equipment (EEE) residues and their management have been widely identified as potential sources of plasticizers and flame retardants to the environment, especially in non-formal e-waste facilities. This study evaluates the distribution, partitioning and environmental and human impact of organophosphate esters (OPEs), legacy polychlorinated biphenyls (PCBs), polybromodiphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in the e-waste recycling area of Baihe Tang village, in the Qingyuan county, Guangdong province, China. A plastic debris lump accumulated in a small pond during years was identified as the main source of pollution with ∑pollutants of 8400 μg/g dw, being OPEs the main contaminants detected, followed by PBDEs. This lump produced the contamination of water, sediments, soils and hen eggs in the surrounding area at high concentrations. Plastic-water and water-sediment partitioning coefficients explained the migration of OPEs to the water body and accumulation in sediments, with a strong dependence according to the K_OW. Triphenyl phosphate (TPhP), tricresyl phosphate (TCPs) and high chlorination degree PCBs produced a risk in soils and sediments, considering the lowest predicted no effect concentration, while the presence of PCBs and PBDEs in free range hen eggs exceeded the acceptable daily intake. OCPs were detected at low concentrations in all samples. The presence of organic contaminants in e-waste facilities worldwide is discussed to highlight the need for a strict control of EEE management to minimize environmental and human risks.

Biomagnification of Persistent Organic Pollutants from Terrestrial and Aquatic Invertebrates to Songbirds: Associations with Physiochemical and Ecological Indicators

Biomagnification of persistent organic pollutants (POPs) is affected by physiochemical properties of POPs and ecological factors of wildlife. In this study, influences on species-specific biomagnification of POPs from aquatic and terrestrial invertebrates to eight songbird species were investigated. The median concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in birds were 175 to 13 200 ng/g lipid weight (lw) and 62.7 to 3710 ng/g lw, respectively. Diet compositions of different invertebrate taxa for songbird species were quantified by quantitative fatty acid signature analysis. Aquatic insects had more contributions of more hydrophobic POPs, while terrestrial invertebrates had more contributions of less hydrophobic PCBs in songbirds. Biomagnification factors (BMFs) and trophic magnification factors had parabolic relationships with log K_OW and log K_OA. The partition ratios of POPs between bird muscle and air were significantly and positively correlated with log K_OA of POPs, indicating respiratory elimination as an important determinant in biomagnification of POPs in songbirds. In this study, the species-specific biomagnification of POPs in songbird species cannot be explained by stable isotopes of carbon and nitrogen and body parameters of bird species. BMFs of most studied POPs were significantly correlated with proportions of polyunsaturated fatty acids in different species of songbirds.

Human exposure to polybrominated diphenyl ethers (PBDEs) through the diet: An update of the scientific literature

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame-retardants (BFRs). As for other persistent organic pollutants, dietary intake (followed by dust inhalation) is the main route of human exposure to PBDEs. In 2012, we reviewed the scientific literature on the concentrations of PBDEs in foodstuffs and their dietary exposure. The current review is aimed at updating the results of recent studies (2012-2022) focused on determining the levels of PBDEs in food samples, as well as the dietary intake of these compounds. We have revised studies conducted over the world. The current information on the concentrations of PBDEs in food and their dietary intake is now much more notable than that available in our previous review, being China the country contributing with the highest number of studies. Because of the important differences in materials and methods used in the available studies, the comparison of results is certainly complicated. However, there seems to be a general trend towards a decrease in the levels of PBDEs in foods, and consequently, in the dietary intake of these contaminants. The lack of tolerable daily intakes of PBDEs is an issue that needs to be solved for assessing human health risks of these BFRs.

Toxic chemicals from uncontrolled e-waste recycling: Exposure, body burden, health impact

Uncontrolled electronic-waste (e-waste) recycling processes have induced serious environmental pollution and human health impacts. This paper reviewed studies on the wide range of toxic chemicals through the use of primitive recycling techniques, their transfer to various ecological compartments, and subsequent health impacts. Results indicated that local food items were heavily polluted by the pollutants emitted, notably heavy metals in vegetables, rice, fish and seafood, and persistent organic pollutants (POPs) in livestock. Dietary exposure is the most important exposure pathway. The associations between exposure to e-waste and high body burdens of these pollutants were evident. It seems apparent that toxic chemicals emitted from e-waste activities are causing a number of major illnesses related to cardiovascular, digestive and respiratory systems, according to the information provided by a local hospital (Taizhou, an e-waste recycling hot spot in China). More epidemiological data should be made available to the general public. It is envisaged that there are potential dangers of toxic chemicals passing on to the next generation via placental transfer and lactation. There is a need to monitor the development and health impacts of infants and children, born and brought up in the e-waste sites.

Occurrence and Distribution of Persistent Organic Pollutants (POPs) in Amphibian Species: Implications from Biomagnification Factors Based on Quantitative Fatty Acid Signature Analysis

Contaminants pose a great threat to amphibian populations, but the bioaccumulation and distribution of contaminants in amphibians are still unclear. Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) had median concentrations of 468-3560 ng/g lipid weight (lw) and 206-2720 ng/g lw in the muscle of amphibians, respectively. BDE 209 was the predominant PBDE congener, while CBs 118, 138, 153, and 180 were the main PCB congeners. The diet compositions of amphibians were estimated by quantitative fatty acid signature analysis (QFASA). Dragonfly contributed the most to the diet of amphibians. Biomagnification factors (BMFs) based on quantitative amphibian/insect relationships showed more credible results than BMFs based on amphibian/each insect or amphibian/combined prey relationships. BMFs derived from QFASA declined with log K_OW from 5 to 6.5 and then showed a parabolic relationship with log K_OW greater than 6.5. BMFs of PCBs were significantly influenced by the elimination capacity of PCBs in amphibians. Less-hydrophobic PCBs preferentially accumulated in the skin than in muscle, which was probably due to the dermal exposure of less-hydrophobic PCBs for amphibians. The biomagnification and distribution of contaminants may be affected by multiple exposure pathways and the toxicokinetics of contaminants in various life stages of amphibians.

The immunotoxicity of decabromodiphenyl ether (BDE-209) on broiler chicks by transcriptome profiling analysis

Decabromodiphenyl ether (BDE-209) has drawn significant attention due to its suppression of immune functions in animals and even humans. In order to explore the mechanism through which BDE-209 affects the immune system, broiler chicks were fed a diet containing various concentrations of BDE-209 (0, 0.004, 0.04, 0.4, and 4 g/kg) for 42 days. Histopathological observations of immune organs found damaged and necrotic lymphocytes in the spleen and bursa, and losses of lymphoid cells in thymic gland. The activities of catalase, glutathione, glutathione peroxidase, and superoxide dismutase in both the spleen and serum were affected by BDE-209. Obvious bioaccumulation effect was found in spleen tissues (high to 1339 ± 181.9 μg/kg). Furthermore, transcriptome sequencing analyses of the spleen identified 424 upregulated and 301 downregulated DEGs, and the cytokine-cytokine receptor interaction signal pathway was most significantly enriched based on the Kyoto Encyclopedia of Genes and Genomes database. Quantitative real-time PCR affirmed the decreased expressions of interleukin IL18, IL18R1, IL18RAP, IL21, as well as interferon gamma IFNG and tumor necrosis factor superfamily members TNFSF8, indicating significant interference to immunomodulation function and possible disease progression in inflammatory effects resulting from BDE-209 exposure. The immunotoxicity of BDE-209 may cause the suppression of immune and physiological functions of spleen cells, leading to inflammation and apoptosis and ultimately spleen atrophy.

Assessment of polybrominated diphenyl ethers and emerging brominated flame retardants in Pheretima (a Traditional Chinese Medicine): Occurrence, residue profiles, and potential health risks

China produces and consumes large quantities of brominated flame retardants (BFRs) as well as several other unregulated electronic waste recycling activities, causing high BFR concentrations in the natural environment. Thus, Traditional Chinese Medicines (TCMs) may be contaminated by legacy BFRs (e.g. polybrominated diphenyl ethers (PBDEs)) and emerging BFRs (eBFRs, such as decabromodiphenyl ethane (DBDPE)) during growth, processing, packaging, and transportation. Pheretima, which is a typical animal drug recorded in Chinese Pharmacopoeia, was used as an example to evaluate human exposure to BFRs through TCM intake. This study is the first to determine 25 PBDEs and 5 eBFRs in Pheretima and estimate the daily BFR intake via Pheretima-containing TCMs. Twenty-seven Shanghai Pheretima and fifty-one Guang Pheretima samples were collected between March and June 2019 in southeast China. High BFR detection frequencies were found in Pheretima, of which BDE-209 and DBDPE were the most predominant analytes. The total PBDE contents ranged from 73 pg/g to 8,725 pg/g, while that of the eBFRs varied between 115 pg/g and 2,824 pg/g. The profiles and abundances were found to be species- and origin-dependent. However, the traditional processing of Pheretima may reduce BFR residues. Based on the usual clinical doses of Pheretima and the available chronic oral reference doses of BDE-47, 99, 153, and 209, the mean (95th percentile) of the total hazard quotient was estimated to be 9.1 × 10^-5 (2.7 × 10^-4). Therefore, there is little risk related to BFR exposure for patients taking formulated Pheretima-containing TCMs. However, it is necessary to establish routine monitoring programs for the co-existence of pollutants in TCMs to perform a systematic and comprehensive risk assessment.

Update of the risk assessment of hexabromocyclododecanes (HBCDDs) in food

The European Commission asked EFSA to update its 2011 risk assessment on hexabromocyclododecanes (HBCDDs) in food. HBCDDs, predominantly mixtures of the stereoisomers α-, β- and γ-HBCDD, were widely used additive flame retardants. Concern has been raised because of the occurrence of HBCDDs in the environment, food and in humans. Main targets for toxicity are neurodevelopment, the liver, thyroid hormone homeostasis and the reproductive and immune systems. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour in mice can be considered the critical effects. Based on effects on spontaneous behaviour in mice, the Panel identified a lowest observed adverse effect level (LOAEL) of 0.9 mg/kg body weight (bw) as the Reference Point, corresponding to a body burden of 0.75 mg/kg bw. The chronic intake that would lead to the same body burden in humans was calculated to be 2.35 μg/kg bw per day. The derivation of a health-based guidance value (HBGV) was not considered appropriate. Instead, the margin of exposure (MOE) approach was applied to assess possible health concerns. Over 6,000 analytical results for HBCDDs in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary LB exposure to HBCDDs were fish meat, eggs, livestock meat and poultry. The CONTAM Panel concluded that the resulting MOE values support the conclusion that current dietary exposure to HBCDDs across European countries does not raise a health concern. An exception is breastfed infants with high milk consumption, for which the lowest MOE values may raise a health concern.

Brominated and phosphate flame retardants from interior and surface dust of personal computers: insights into sources for human dermal exposure

It remains unclear whether internal or external sources play the more significant role in flame retardant (FR) contamination of surface dust from personal computers (PCs), which may lead to bias on dermal exposure assessment of FRs. In the present study, the occurrence and profiles of several brominated and phosphate FRs were measured in the interior dust, and the upper surface (keyboard) and bottom surface (bottom cover) wipes of PCs. BDE 209 (639 ng/g), decabromodiphenyl ethane (DBDPE, 885 ng/g), and triphenyl phosphate (TPHP, 1880 ng/g) were the most abundant chemicals in interior PC dust, while tris(2-chloroisopropyl) phosphate (TCIPP), TPHP, and DBDPE were dominant on both surfaces of PCs. No significant correlation between interior dust and both PC surfaces was observed for concentrations of most FRs except BDE 183. Different sources of FRs for interior and surface dust of PCs were further revealed by principal component analysis (PCA). FRs from external sources, rather than emission from inner PC components, are likely the main contributor for FR profiles on PC surfaces. Exposure assessment results demonstrated a minor contribution from PC dermal contact, compared with hand-to-mouth uptake, to total exposure. The applicability of surface wipes to assess dermal exposure to FR-treated products needs to be further investigated.

Nephrotoxicity and possible mechanisms of decabrominated diphenyl ethers (BDE-209) exposure to kidney in broilers

The flame retardant decabrominated diphenyl ether (BDE-209) is a widely used chemical in a variety of products and exists extensively in the environment. BDE-209 has been reported to induce kidney injury and dysfunction. However, the causes and mechanisms of its nephrotoxicity are still under investigation. In this study, 150 male broilers were exposed to BDE-209 concentrations of 0, 0.004, 0.04, 0.4, 4.0 g/kg for 42 days. The relative kidney weight, histopathology, markers of renal injury, oxidative stress, inflammation, apoptosis and the expression of MAPK signaling pathways-related proteins were assessed. The results showed that the concentrations of blood urea nitrogen (BUN), creatinine (CRE) and the neutrophil gelatinase-associated lipocalin (NGAL), significantly increased after exposure to BDE-209 with the doses more than 0.04 g/kg. Similarly, severe damage of renal morphology was observed, including atrophy and necrosis of glomeruli, and swelling and granular degeneration of the renal tubular epithelium. In the renal homogenates, the oxidative stress was evidenced by the elevated concentrations of MDA and NO, and decreased levels of GSH-Px, GSH and SOD. Due to the inflammatory response, the level of NF-κB and the pro-inflammatory cytokines TNF-α, IL-1β, IL-18 were remarkably upregulated, while the content of the anti-inflammatory cytokine IL-10 decreased. Additionally, the apoptotic analysis showed notable upregulations of Bax/Bcl-2 ratio, the relative expression of p-ERK1/2 and p-JNK1/2, and the expression of Bax, cytochrome c and caspase 3. The present study indicates that BDE-209 exposure can cause nephrotoxicity in broilers through oxidative stress and inflammation, which activate the phosphorylation of key proteins of the MAPK signaling pathways, and subsequently induce mitochondria-mediated kidney apoptosis.

Dechlorane Plus and Related Compounds in Food-A Review

Dechlorane Plus is a polychlorinated compound which has exclusively anthropic origin. This compound has been manufactured for close to 60 years for various applications, but mainly as flame retardant. Dechlorane Plus and other Dechlorane-related compounds (DRCs) are currently marketed as a replacement for Dechlorane, also known as Mirex, banned in 1978. These compounds share comparable properties to persistent organic pollutants (POPs), such as persistence in the environment, high lipophilicity, bioaccumulation through the food web and adverse effects on the environment and human health. Despite their long production history, they have been only recently reported in various environmental compartments, such as air, soil, and foodstuff. The aim of this review is to provide a picture of the current state of knowledge on worldwide DRC levels in food, in order to highlight gaps and research needs. The review compares the data on DRC contamination available in literature, considering different food categories and sampling country. In addition, it is specified whether the data were obtained from studies on foodstuff to estimate dietary intake, to evaluate the contamination near the e-waste treatment area or for environmental monitoring purposes.

Tetrabromobisphenol A and hexabromocyclododecanes in sediments and biota from two typical mangrove wetlands of South China: Distribution, bioaccumulation and biomagnification

Tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) were examined in sediments and biota species from two mangrove wetlands of the Pearl River Estuary (PRE) and the Jiulong River Estuary (JRE), South China, to investigate their distribution, bioaccumulation and biomagnification in mangrove food webs. Levels of TBBPA and ΣHBCD (sum of α-, β- and γ-HBCDs) ranged from 0.003 to 0.31 and not detected (nd) to 1.11 ng/g dry weight in the sediments, and from 0.56 to 22.1 and nd to 56.3 ng/g lipid weight in the biota species, respectively. γ-HBCD was the major diastereoisomer in the PRE sediments, while α- and γ-HBCDs predominated in the JRE sediments. In contrast, α-HBCD was dominant in the biota. Mean enantiomeric fractions (EFs) of α-, β- and γ-HBCDs in the sediments all followed the trend of JRE > racemic standard > PRE. A significant enrichment of (-)-α-HBCD was found in the biota (p = 0.04), with EFs in the range of 0.297-0.485. Bioaccumulations were seen for TBBPA and α-HBCD as their biota-sediment accumulation factors (BSAFs) were greater than 1. (-)-α-HBCD had significantly greater BSAFs than (+)-α-HBCD (p = 0.04), indicating the preferential bioaccumulation of (-)-α-HBCD. Biomagnification factors (BMFs) of TBBPA ranged from 0.83 to 1.51, which varied among feeding relationships and mangroves. Positive relationships were found between TBBPA concentrations and trophic levels of the biota species with trophic magnification factors of 2.17 for the PRE and 1.22 for the JRE, suggesting that TBBPA biomagnifies in the mangrove food webs. No biomagnifications were observed for ΣHBCD, α-HBCD and its enantiomers.

Effects of cooking on oral bioaccessibility of PBDEs, MeO-PBDEs, and OH-PBDEs in fish (tilapia) and chicken egg

Human health concerns are rising with polybrominated diphenyl ethers' (PBDEs) analogues, methoxylated and hydroxylated PBDEs (MeO-PBDEs and OH-PBDEs), due to their occurrences in foods and greater potential toxicological effects than PBDEs. While the oral bioaccessibilities (BA%) of PBDEs in foods are available, such information on MeO-PBDEs and OH-PBDEs, and the effects of cooking on them have not been adequately addressed. The present study was conducted with fish and chicken egg as typical foods to assess the bioaccessibility (BA%) of PBDEs, MeO-PBDEs, and OH-PBDEs using the colon extended physiologically based extraction test and examine the effects of cooking processes (boiling, frying, and steaming) on them. The results showed that thermal degradation or transformation of the target compounds did not occur during boiling and frying of fish. The BA% of individual PBDEs, MeO-PBDEs, and OH-PBDEs were 20-51% for boiled fish, 11-20% for pan-fried fish, 15-77% for steamed egg, and 42-68% for pan-fried egg. Cooking decreased the BA% of all target compounds in fish due to protein denaturation. However, the BA% of OH-PBDEs in pan-fried egg were greater than those in steamed egg. In addition, the substituent groups of CH₃O- and OH- did not pose any effects on the BA% of BDE-47 in fish, but OH-group decreased its BA% in egg. These findings suggested that MeO-PBDEs and OH-PBDEs exhibited the similar oral BA% in fish to PBDEs, but the underlying mechanism for the effects of cooking on BA% of OH-PBDEs in egg needs to be further investigated.

Human exposure to PBDEs in e-waste areas: A review

Polybrominated biphenyl ethers (PBDEs) are commonly added to electronic products for flame-retardation effects, and are attracting more and more attentions due to their potential toxicity, durability and bioaccumulation. This study conducts a sysmtematic review to understand the human exposure to PBDEs from e-waste recycling, especially exploring the exposure pathways and human burden of PBDEs as well as investigating the temporal trend of PBDEs exposure worldwide. The results show that the particular foods (contaminated fish, poultry, meat and breast milk) ingestion, indoor dust ingestion and indoor air inhalation may be key factors leading to human health risks of PBDEs exposure in e-waste recycling regions. Residents and some vulnerable groups (occupational workers and children) in e-waste recycling areas may face higher exposure levels and health risks. PBDE exposure is closely related to exposure level, exposure duration, e-waste recycling methods, and dietary customs. High levels of PBDEs are found in human tissues (breast milk, hair, blood (serum), placenta and other tissues) in e-waste areas, at far higher levels than in other areas. Existing data indicate that PBDE exposure levels do not present any apparent downward trend, and will possibly cause serious human diseases. More epidemiological studies are still needed to provide a solid basis for health risk assessment.

Leaching of brominated flame retardants (BFRs) from BFRs-incorporated plastics in digestive fluids and the influence of bird diets

Leaching kinetics of additive-derived brominated flame retardants (BFRs) in different sizes (100 μm-2 mm) of acrylonitrile-butadiene-styrene copolymer (ABS) plastics were investigated in water, simulated gastric fluids, and simulated gastrointestinal fluids. The influences of bird diets (fish, clam, and rice) on the leaching of BFRs from plastics were also explored. The leaching kinetics of BFRs were best fitted with the second-order diffusion model. The leaching rates of BFRs increased for the less lipophilic BFRs in finer sizes of ABS. The log-transformed leached proportions of BFRs at equilibrium were significantly correlated with logK_OW of BFRs (p < 0.05). BFRs migrated from ABS to digestive fluids and diet residues at equilibrium, since elevated concentrations of BFRs were observed in diet residues than virgin diet samples. Leached proportions of BFRs in gut fluids from mixture of ABS and diets were lower than those from only ABS. The logK_OW of BFRs and the migration proportions of BFRs from ABS to digestive fluids and diet residues were fitted with linear regression analysis. The results indicate that more lipophilic BFRs are preferentially leached from BFRs-incorporated plastics into fluids and are further adsorbed by diet residues.

Alternative halogenated flame retardants (AHFRs) in green mussels from the south China sea

Restrictions of legacy brominated flame retardants, such as polybrominated diphenyl ether (PBDE) and polybrominated biphenyl (PBB), have resulted in increased usage of alternative halogenated flame retardants (AHFRs). Consequently, AHFRs contamination has caused a major concern in the scientific community. However, there is limited information on their presence in marine mussels. In this study, we investigated the occurrence and distribution of polybrominated biphenyls (PBBs), AHFRs and dehalogenated products in green mussels collected from 22 locations in the northern South China Sea (SCS). Our results revealed that ∑AHFRs were ubiquitous in green mussels with concentrations in the range of 1.08-7.71 ng/g lipid weight (lw). Among target AHFRs, hexabromobenzene (HBB), decabromodiphenyl (DBDPE) and dechlorane plus (DP) were predominant with their mean values of 1.19, 1.00 and 0.82 ng/g lw, respectively. There were negligible stereoisomer enrichments of DP in green mussels based on f_anti values, indicating a limited bioaccumulation and metabolism of DP in green mussels. In comparison with other locations, concentrations of the AHFRs in green mussels determined here were at moderate levels. Additionally, there were significant linear relationships between some AHFRs (e.g., HBB and PBEB), suggesting their similar commercial applications and sources in the environment. The estimated daily intakes of AHFRs through consumption of green mussels by the local population in South China were 0.05-0.14 ng/kg body weight/day and 0.17-0.44 ng/kg body weight/day based on the mean and 95th concentrations, respectively. To the best of our knowledge, the present study is the first to report AHFRs and dehalogenated products in green mussels.

Bioaccumulation and biomagnification of hexabromocyclododecane (HBCDD) in insect-dominated food webs from a former e-waste recycling site in South China

Hexabromocyclododecane (HBCDD) has frequently been detected in wildlife. However, there is limited research on its bioaccumulation and biomagnification in insect-dominated aquatic and terrestrial food webs. This study investigated the occurrence of HBCDD in insects and their predators collected from a former e-waste contaminated pond and its surrounding region. The concentrations of ƩHBCDD (sum concentrations of α-, β-, and γ-HBCDDs) ranged from nd to 179 ng g^-1 lipid weight. α-HBCDD was the predominant diastereoisomer in all biotic samples, and the contribution of α-HBCDD was higher in predators than in prey insects. A significantly positive linear relationship was found between ƩHBCDD concentrations (lipid weight) and trophic levels based on δ¹⁵N in aquatic organisms (p < 0.05), while trophic dilution was observed in the terrestrial food web. This result indicates an opposite trophic transfer tendency of HBCDD in terrestrial and aquatic ecosystems. The biomagnification factor (BMF) for α-HBCDD was higher in terrestrial birds (2.03) than in frogs (0.29), toads (0.85), and lizards (0.63). This may be due to differences between poikilotherms and homeotherms in terrestrial ecosystems.

Do farming conditions influence brominated flame retardant levels in pig and poultry products?

Brominated flame retardants (BFR) are primarily used as flame retardant additives in insulating materials. These lipophilic compounds can bioaccumulate in animal tissues, leading to human exposure via food ingestion. Although their concentration in food is not yet regulated, several of these products are recognised as persistent organic pollutants; they are thought to act as endocrine disruptors. The present study aimed to characterise the occurrence of two families of BFRs (hexabromocyclododecane (HBCDD) and polybrominated diphenyl ethers (PBDE)) in hen eggs and broiler or pig meat in relation to their rearing environments. Epidemiological studies were carried out on 60 hen egg farms (34 without an open-air range, 26 free-range), 57 broiler farms (27 without an open-air range, 30 free-range) and 42 pig farms without an open-air range in France from 2013 to 2015. For each farm, composite samples from either 12 eggs, five broiler pectoral muscles or three pig tenderloins were obtained. Eight PBDE congeners and three HBCDD stereoisomers were quantified in product fat using gas chromatography-high-resolution mass spectrometry, or high-performance liquid chromatography-tandem mass spectrometry, respectively. The frequencies of PBDE detection were 28% for eggs (median concentration 0.278 ng/g fat), 72% for broiler muscle (0.392 ng/g fat) and 49% for pig muscle (0.403 ng/g fat). At least one HBCDD stereoisomer was detected in 17% of eggs (0.526 ng/g fat), 46% of broiler muscle (0.799 ng/g fat) and 36% of pig muscle (0.616 ng/g fat). Results were similar in concentration to those obtained in French surveillance surveys from 2012 to 2016. Nevertheless, the contamination of free-range eggs and broilers was found to be more frequent than that of conventional ones, suggesting that access to an open-air range could be an additional source of exposure to BFRs for animals. However, the concentration of BFRs in all products remained generally very low. No direct relationship could be established between the occurrence of BFRs in eggs and meat and the characteristics of farm buildings (age, building materials). The potential presence of BFRs in insulating materials is not likely to constitute a significant source of animal exposure as long as the animals do not have direct access to these materials.

The leaching of additive-derived flame retardants (FRs) from plastics in avian digestive fluids: The significant risk of highly lipophilic FRs

The exposure to plastic debris and associated pollutants for wildlife is of urgent concern, but little attention has been paid on the transfer of plastic additives from plastic debris to organisms. In the present study, the leaching of incorporated flame retardants (FRs), including polybrominated diphenyl ethers (PBDEs), alternative brominated FRs (AFRs), and phosphate flame retardants (PFRs), from different sizes of recycled acrylonitrile-butadiene-styrene (ABS) polymer were investigated in avian digestive fluids. The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored. In the recycled ABS, BDE 209 (715 μg/g) and 1, 2-bis(2,4,6-tribromophenoxy) ethane (BTBPE, 1766 μg/g) had the highest concentrations among all target FRs. The leaching proportions of FRs were higher in finer sizes of ABS. The leaching proportions of FRs from recycled ABS increased with elevated logK_OW of FRs. In the tests with coexisted ABS and sediment, hexa- to deca-BDEs, BTBPE, and decabromodiphenyl ethane (DBDPE) migrated from ABS to sediment, which resulted in the less bioaccessible fractions of these FRs in gut fluids. More lipophilic chemicals tended to be adsorbed by sediment from ABS. The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids. The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds, and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.

Evaluation of the QuEChERS and magnetic micro dispersive solid-phase extraction of brominated flame retardants in red fruits with determination by GC/MS

A sample preparation method, QuEChERS extraction combined with a magnetic micro dispersive solid phase extraction (MµdSPE), was optimized and evaluated for the trace analysis of 9 brominated flame retardants in red fruit samples (strawberries, blueberries, and raspberries) using gas chromatography-mass spectrometry. Magnetic nanomaterials were used as sorbents providing an extraction of the target compounds. Linearity was established for all the analytes (from 10 to 200 µg kg^-1). Seven concentration levels were analyzed with three measurements at each concentration. Linear responses (R² > 0.99) were obtained, recoveries of all target analytes were within the range of 65-141%, relative standard deviations were <20% at all three spiking levels, while intraday and interday precisions were below 20%. This study demonstrated that the new sample preparation with magnetic nanoparticles could potentially be expanded to extract and pre-concentrate the BFRs in different red fruit samples. The method has been successfully applied to study BFRs in 12 samples from conventional and organic farming.

Polybrominated diphenyl ethers (PBDEs) in chicken eggs and cow milk around municipal dumpsites in Abuja, Nigeria

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in electronic equipment, as polymers in vehicles or construction, and in textiles. These additive flame retardants are emerging pollutants in Africa, released by the non-environmentally sound disposal of consumer products, often imported as secondhand, that have increasingly reached their end-of-life in the last decade. In Nigeria, which is a major receiver of e-waste and secondhand cars, there is a dearth of information regarding the levels of PBDEs in the environment, biota, and food. Thus, this study was designed to investigate the PBDE contamination of food samples of animal origin (chicken eggs and cow milk) around municipal waste dumpsites and background areas in Nigeria, to elucidate the role of dumpsites as potential sources of PBDE pollution and exposure in the country. Biological samples were collected over two years from two municipal waste dumpsites in Abuja. Fifty-six samples each of free-range chicken eggs and cow milk were collected. Control samples were collected approximately 5 km away from the dumpsites. After extraction and clean-up, the levels of POP-PBDEs listed in 2009 (major congeners of tetraBDE to heptaBDE), plus BDE-28 (Σ₇PBDEs) were determined using GC-ECD. Data were analysed using descriptive statistics, t-test at α_0.05. Levels of Σ₇PBDEs (ng/g lipid weight (lw)) in chicken eggs at the two study sites ranged from 262.3 to 313.4 (ng/g lw), more than one order of magnitude higher than those at the control site in a village near the dumpsites (14.9 ± 3.73 ng/g lw), and two and more orders of magnitude higher compared to PBDE levels in these products in industrial countries and Nigerian supermarkets. Median PBDE levels in cow milk from the two dumpsites were 49.1 and 81.5 ng/g lw, respectively, considerably higher than levels in other studies. Proper disposal methods of waste polymers containing PBDEs such as co-incineration in BAT cement kilns and plastic recycling with separation is urgently needed in Nigeria and other parts of Africa, to prevent open burning as well as crude recycle to reduce PBDE levels in the environment and human food.

Human exposure pathways to organophosphate flame retardants: Associations between human biomonitoring and external exposure

Organophosphate flame retardants (PFRs) have largely replaced the market of polybrominated diphenyl ethers (PBDEs). Concerns about PFR contamination and its impact on human health have consequently increased. A comprehensive investigation on the human exposure pathways to PFRs is to be endeavoured. This study investigated the occurrence of PFR metabolites in human urine, serum and hair, correlating them with external exposure data that was presented in our previous studies. Participants from Oslo (n = 61) provided a set of samples, including dust, air, handwipes, food, urine, serum and hair. Associations between PFR metabolites analyzed in the biological samples and the PFRs in environmental samples were explored. Different sampling strategies for dosimeters (e.g. floor/surface dust, personal/stationary air) were also compared to understand which is better for predicting human exposure to PFRs. Seven out of the eleven target PFR metabolites, including diphenyl phosphate (DPHP) and bis(1-chloro-2-propyl)-1-hydroxy-2-propyl phosphate (BCIPHIPP), were frequently detected (DF > 30%) in urine. DPHP was the most frequently detected metabolite in both serum and hair. Several PFR metabolites had higher levels in morning urine than in afternoon urine. Floor dust appeared to be a better proxy for estimating PFR internal exposure than surface dust, air, and handwipes. Some PFRs in handwipes and air were also correlated with their metabolites in urine and hair. Age, beverage consumption and food consumption were negatively associated with DPHP levels in urine. Discrepancies observed between the external and internal exposure for some PFRs call for further investigation on PFR bioaccessibility and clearance.

Biomagnification of PBDEs and alternative brominated flame retardants in a predatory fish: Using fatty acid signature as a primer

Information on biomagnification of alternative brominated flame retardants (ABFRs) is limited and results are inconclusive, due in part to uncertainty in the understanding of predator/prey relationships. In the present study, a predatory fish, Channa argus, and several forage fish species were obtained from an ABFR contaminated site. The predator/prey relationships were identified based on fatty acid (FA) signatures in the predator and prey. Biomagnification factors (BMFs) for several ABFRs including decabromodiphenyl ethane (DBDPE), 1,2‑bis(2,4,6‑tribromophenoxy) ethane (BTBPE), hexabromobenzene (HBB), pentabromotoluene (PBT), and pentabromoethylbenzene (PBEB) were estimated based on the identified predator/prey relationships. The results showed that crucian carp was the main prey of C. argus, contributing to 71%-100% to its total diet. The mean BMFs for DBDPE, BTBPE, and HBB were 0.06, 0.40, and 0.91, respectively, indicating trophic dilution of these ABFRs. However, biomagnification of PBT and PBEB, with BMFs of 2.09 and 2.13, respectively, was observed. The BMFs for PBT, PBEB and HBB were comparable to or even higher than those for some polybrominated diphenyl ether (PBDE) congeners estimated in the same individual predator, indicating that these emerging pollutants may pose significant environmental risks. The BMFs for ABFRs and PBDEs were significantly and negatively correlated to the log K_OWs of these chemicals, suggesting that the biomagnification of these chemicals was depressed due to their superhydrophobic nature.

Dechlorane plus in greenhouse and conventional vegetables: Uptake, translocation, dissipation and human dietary exposure

In an attempt to evaluate the behavior of Dechlorane plus (DP) in soil-vegetable systems, this work investigated the uptake and translocation of DP by vegetables and the dissipation of DP in soil under greenhouse and conventional conditions. To address human dietary exposure to DP, estimated dietary intake via vegetable consumption was calculated. The uptake potential indexes of DP from soil into root for tomato and cucumber cultivated under different conditions ranged from 0.089 to 0.71. The ranges of uptake potential indexes of DP from resuspended soil particles into stem, leaf and fruit were 0.68-0.78, 0.27-0.42 and 0.39-0.75, respectively. The uptake potential indexes in greenhouse vegetables were generally higher than those in conventional vegetables when the vegetables had been planted in contaminated soil, indicating that greenhouse enhanced the uptake of DP with a high soil concentration by vegetables. The translocation factor (TF) values of DP in vegetables were in the range of 0.022-0.17, indicating that DP can be transported from root to fruit even though it has a high octanol water partition coefficient (K_OW). The half-lives of DP dissipation in soil ranged from 70 to 102 days. The dissipation of DP in greenhouse soil was slightly slower than that in conventional soil. Higher estimated dietary intake (EDI) values of DP via greenhouse vegetables were observed due to the higher concentration of DP in greenhouse vegetables than conventional vegetables. These results suggested that greenhouses should not be adopted for vegetable production in contaminated regions.

Enantioselectivity in biotransformation and bioaccumulation processes of typical chiral contaminants

Chirality is a critical topic in the medicinal and agrochemical fields. One quarter of all agrochemicals was chiral in 1996, and this proportion has increased remarkably with the introduction of new compounds over time. Despite scientists have made great efforts to probe the enantiomeric selectivity of chiral chemicals in the environment since early 1990s, the different behaviours of individual enantiomers in biologically mediated processes are still unclear. In the present review, we highlight state-of-the-knowledge on the stereoselective biotransformation and accumulation of chiral contaminants in organisms ranging from invertebrates to humans. Chiral insecticides, fungicides, and herbicides, polychlorinated biphenyls (PCBs), pharmaceuticals, flame retardants hexabromocyclododecane (HBCD), and perfluorooctane sulfonate (PFOS) are all included in the target compounds. Key findings included: a) Changes in the enantiomeric fractions in vitro and in vivo models revealed that enantioselectivity commonly occurs in biotransformation and bioaccumulation. b) Emerging contaminants have become more important in the field of enantioselectivity together with their metabolites in biological transformation process. c) Chiral signatures have also been regarded as powerful tools for tracking pollution sources when the contribution of precursor is unknown. Future studies are needed in order to understand not only preliminary enrichment results but also detailed molecular mechanisms in diverse models to comprehensively understand the behaviours of chiral compounds.

Level changes and human dietary exposure assessment of halogenated flame retardant levels in free-range chicken eggs: A case study of a former e-waste recycling site, South China

To assess the impacts of e-waste regulations on environmental pollution, we built on a previous study from 2010 to investigate the levels and human dietary exposure of halogenated flame retardants (HFRs) in free-range chicken eggs from Baihe village in 2013 and 2016. The concentrations of PBDEs, PBBs, HBCDs, and DBDPE showed a significant decrease (p<0.05) from 2010 to 2013/2016, suggesting the efficacy of regulatory policies. The relative contribution of BDE209 were higher in 2013 and 2016 than in 2010, accounting for 67.8%, 61.4%, and 27.7%, respectively. The concentration ratios of PBB209:PBB153 were much lower in 2013 (1.51) and 2016 (1.32) than in 2010 (29.5). These observed different profiles likely due to the different environmental behaviors of HFRs (e.g. the different atmospheric migration abilities of PBDE congeners and degradation of PBB209). Our exposure estimates suggested high dietary intake of HFRs via home-produced eggs. As for PBDEs, considering the worst situation (highly polluted eggs were consumed), the margin of exposure (MOE) of BDE99 for both adults and children were 1.5 and 0.3 in 2013, and 1.1 and 0.2 in 2016, respectively, which were below 2.5. According to the CONTAM panel, an MOE larger than 2.5 indicates no health concern. Therefore, these MOE values represent a significant potential health concern due to the adverse impacts of PBDEs on human neurodevelopment and fertility.

Urinary metabolites of phosphate flame retardants in workers occupied with e-waste recycling and incineration

Urinary metabolites of phosphate flame retardants (PFRs) were determined in workers from an electronic waste (e-waste) recycling site and an incineration plant, in order to assess the PFR exposure risks of workers occupied with e-waste recycling and incineration. Bis(2-chloroethyl) phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP) were the most frequently detected chemicals (82-93%). The median concentrations of BCEP, BDCIPP, and DPHP were 1.77, 0.23, and 0.70 ng/mL, and 1.44, 0.22, and 0.11 ng/mL in samples from the e-waste site and the incineration plant, respectively. Dibutyl phosphate (DBP) was detected in all samples from the incineration plant, with a median level of 0.30 ng/mL. The concentrations of BDCIPP (r = -0.31, p < 0.05) were significantly correlated with the occupational exposure time rather than age in workers from the e-waste site. Negative and significant correlations were also observed between the concentrations of BCEP (r = -0.42, p < 0.05), BDCIPP (r = -0.37, p < 0.05), and DPHP (r = -0.37, p < 0.05) and occupational exposure time rather than age in workers from the incineration plant. No gender differences were observed in levels of PFR metabolites in urine samples (p > 0.05). Concentrations of BDCIPP in female were significantly correlated with occupational exposure time (r = -0.507, p < 0.01). Concentrations of PFR metabolites in male were not significantly correlated with age or occupational exposure time (p > 0.05). Overall, the workers with occupational exposure to PFRs had different profiles of urinary PFR metabolites. The age, occupational exposure time, and gender seemed not to be main factors mediating the exposure to PFRs for workers occupied with e-waste recycling and incineration.

Legacy and emerging brominated flame retardants in China: A review on food and human milk contamination, human dietary exposure and risk assessment

Brominated flame retardants (BFRs) are a large group of widely used chemicals, which have been produced and used since 1970s. As a consequence of substantial and long-term usage, BFRs have been found to be ubiquitous in humans, wildlife, and abiotic matrices around the world. Although several reports have reviewed BFRs contamination in general, none have focused specifically on foods and human milk, and the corresponding dietary exposure. Foods (including human milk) have long been recognized as a major pathway of BFRs intake for non-occupationally exposed persons. This review summarizes most available BFRs data in foods and human milk from China in recent years, and emphasizes several specific aspects, i.e., contamination levels of legacy and emerging BFRs, dietary exposure assessment and related health concerns, comparison between various BFRs, and temporal changes in BFRs contamination.

Flame retardants on the surface of phones and personal computers

Mobile phones and personal computers (PCs) are essential products that are frequently contacted in daily life. Thus, phones and computers containing flame retardants (FRs) may play vital roles in human exposure to FRs. We measured several FRs, including polybrominated diphenyl ethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), decabromodiphenyl ethane (DBDPE), tetrabromobisphenol (TBBPA), and phosphate flame retardants (PFRs), on the surfaces of phones and PCs (laptop keyboards and mice). Triphenyl phosphate (TPHP, 228pg/cm²) and tris(chloroisopropyl) phosphate (TCIPP, 43pg/cm²) were the most abundant chemicals on the surfaces of phones, while TPHP (65pg/cm²), TCIPP (48pg/cm²), and DBDPE (22pg/cm²) were dominant on the surfaces of PCs. The usage time and time after the production of the electronics were not significantly correlated with the FR concentrations, except for that of BDE 209. The concentrations of FRs differed on the surfaces of different brands of electronics. Dermal contact with the surface of electronics may contribute to human exposure to FRs, which should be of concern.

Hens can ingest extruded polystyrene in rearing buildings and lay eggs contaminated with hexabromocyclododecane

The overall concentration of hexabromocyclododecane (HBCDD) in eggs is low although abnormally high concentrations exceeding 3000 ng g^-1 lw have been reported. In order to test whether these contaminations may originate from the ingestion of insulating materials in rearing buildings, a group of 55 hens raised in a collective cage was provided with a 64-g piece of extruded polystyrene (XPS, 2.59% HBCDD of which 75, 15 and 10% as α-, β- and γ-HBCDD, respectively). Hens entirely consumed the piece within 3 days, leading to a mean daily exposure of 4.7 mg HBCDD per kg body weight. Whole egg HBCDD concentration reached a maximum of 1037 ng HBCDD g^-1 fresh weight (fw), recorded 2 days after the piece had disappeared, and decreased down to 86 ng g^-1 fw within the 19 following days. In all these samples, HBCDD was made of 98.7 ± 0.7 and 1.3 ± 0.6% α- and β-HBCDD, respectively, and 0.1% γ-HBCDD when quantified; it was enriched in (-)α- and (+)β-HBCDD with enantiomeric fractions of 0.438 ± 0.009 and 0.579 ± 0.030, respectively. HBCDD was quantified in all the individual eggs collected the last day of experiment at concentrations ranging between 0.47 and 1361 ng g^-1 fw, according to a lognormal distribution. The ingestion of XPS in degraded rearing buildings is thus a plausible cause of on-farm egg contamination by HBCDD which should be strictly avoided.

Pyrethroids in chicken eggs from commercial farms and home production in Rio de Janeiro: Estimated daily intake and diastereomeric selectivity

In this study, pyrethroids were determined in chicken eggs from commercial farm (n = 60) and home egg production (n = 30). These pyrethroids were investigated: bifenthrin, phenothrin, permethrin, cyfluthrin, cypermethrin and fenvalerate, including most diastereomers. Quantification was done using GC-MS in a negative chemical ionization mode. Pyrethroids residues were found in 79% of the analyzed samples. Cypermethrin presented the highest occurrence, being quantified in 62 samples (69%) in concentrations (lipid weight - l w.) varying between 0.29 and 6408 ng g^-1, followed by phenothrin (24%), 21-3910 ng g^-1, permethrin (14%), 2.96-328 ng g^-1, and bifenthrin (11%), 3.77-16.7 ng g^-1. Cyfluthrin and fenvalerate were not detected. Home-produced eggs had a higher occurrence of pyrethroids (97%), with a greater predominance of phenothrin. In commercial production, 70% of the samples presented pyrethroid residues (predominantly cypermethrin). This is the first report about the presence of pyrethroids in home-produced eggs and the first description of a selectivity pattern with the predominance of cis diastereomers in chicken eggs. In general, estimated daily intake does not present a risk to human consumption, according to Brazilian and international standards (FAO/WHO). However, one third of the samples (30 eggs) had concentrations above the maximum residue limits (MRLs). The maximum cypermethrin concentration was 66 times the MRL, while the maximum phenothrin concentration was 11 times the limit. Further studies about transfer dynamics, bioaccumulation and metabolic degradation of stereoisomers are required, as well as determining if this selectivity pattern in food can increase consumer's health risk.

Brominated and phosphate flame retardants (FRs) in indoor dust from different microenvironments: Implications for human exposure via dust ingestion and dermal contact

Indoor dust has been widely used to monitor flame retardants (FRs) in indoor environment, but most studies only focused on floor dust. In the present study, FRs were examined in indoor dust from different locations. Dust from air conditioner (AC) filters, beddings, floor, and windows in bedrooms, and dust from AC filters, printer table surface, computer table surface, floor, and windows in offices were collected, respectively. Polybrominated diphenyl ether congener 209 (BDE 209) and decabromodiphenyl ethane (DBDPE) were the most abundant brominated flame retardants (BFRs), and tris(chloroisopropyl) phosphate (TCIPP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP), and triphenyl phosphate (TPHP) were the most abundant phosphate flame retardants (PFRs). In bedrooms, the AC filter dust had the highest median levels of BDE 209 (536 ng/g) and DBDPE (2720 ng/g), while bed dust had the highest median levels of ΣPFRs (2750 ng/g) among dust samples. In offices, printer table dust had higher median levels of BDE 209 (1330 ng/g), DBDPE (8470 ng/g), and ΣPFRs (11,000 ng/g) than those in other dust samples. The high dust ingestion values of BDE 209, DBDPE, and individual PFR were 0.28, 1.20, and <0.01-0.32 ng/kg bw/day and 7.37, 31.2, and <0.01-4.54 ng/kg bw/day for BDE 209, DBDPE, and individual PFR for adults and toddlers, respectively. The high dermal exposure values of individual PFR during sleeping were <0.01-0.23 and <0.01-0.36 ng/kg bw/day for adults and toddlers, respectively. More human exposure pathways other than dust ingestion should be considered, such as the dermal contact with beddings and furniture.

Emerging and legacy flame retardants in UK human milk and food suggest slow response to restrictions on use of PBDEs and HBCDD

The legacy flame retardants (LFRs) polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD), together with six emerging flame retardants (EFRs) were measured in United Kingdom (UK) human milk collected in 2010 (n=25) and 2014-15 (n=10). These data are the first report of the presence of EFRs in UK human milk. The most abundant EFR was β-tetrabromoethylcyclohexane (DBE-DBCH) (average=2.5ng/g lw; geometric mean=1.5ng/g lw), which is comparable to the concentrations of the most abundant LFRs i.e. BDE 47 and α-HBCDD at 2.8 and 2.1ng/g lw, respectively (geometric mean=2.1 and 1.7). The estimated median dietary intake of ΣEFRs by UK nursing infants was 18ng/kg bw/day. EFRs were also measured in UK foodstuffs with β-DBE-DBCH again the predominant compound detected, accounting - on average - for 64.5±23.4% of ΣEFRs. Average estimated dietary intakes of ∑EFRs in the UK were 89 and 26ng/day (1.3 and 2.6ng/body weight/day) for adults and toddlers, respectively. Concentrations of Σtri-hexa BDEs in our UK food samples exceeded those reported in UK samples from the same food categories collected in 2003-04 and 2006. Despite this and our recent report elsewhere of significant temporal declines in concentrations of BDE 209 in UK indoor dust (p<0.05) and HBCDDs in UK indoor dust and air (p<0.001), no significant temporal differences (p>0.05) were observed between concentrations of Σtri-hexa BDEs, BDE 209 and HBCDDs in human milk sampled in 2010 and those obtained in 2014-15. UK adult body burdens for EFRs were predicted via inhalation, diet and dust ingestion using a simple pharmacokinetic model. The predicted EFR body burdens compared well with observed concentrations in human milk.

Accumulation of α-hexabromocyclododecane (α-HBCDD) in tissues of fast- and slow-growing broilers (Gallus domesticus)

The aim of the current study was to describe the fate of ingested α-hexabromocyclododecane (α-HBCDD) in fast-growing (FG) and slow-growing (SG) broilers, through an exposure to a dietary concentration of 50 ng α-HBCDD g^-1 feed during 42 and 84 days, respectively. Depuration parameters were assessed in SG broilers successively exposed during 42 days and depurated during 42 days. At market age, SG broilers had ingested 42% more feed than FG broilers, while their body weight gain per g of feed ingested was 34% lower. No isomerization of α- to β- or γ-HBCDD forms occurred, while OH-HBCDD was identified as a product of α-HBCDD metabolism. Irrespective of the strain, abdominal fat displayed the highest α-HBCDD concentration on a lipid weight basis, followed leg muscles and then breast muscle, liver and plasma. The accumulation ratios of α-HBCDD were slightly higher in SG (6.7, 2.1, 2.6 and 9.9 in leg muscles, breast muscle, liver and abdominal fat, respectively) than in FG broilers (5.2, 2.2, 1.1 and 8.4, respectively). The elimination half-lives in SG broilers were 20, 12 and 19 d in leg muscles, breast muscle and abdominal fat, respectively, to which dilution through growth contributed for around 50%. The overall assimilation efficiency of α-HBCDD was estimated at 58 and 50% in FG and SG broilers, respectively, while 22 and 17% of α-HBCDD ingested were estimated to be eliminated in excreta as metabolites.

Alteration of Diastereoisomeric and Enantiomeric Profiles of Hexabromocyclododecanes (HBCDs) in Adult Chicken Tissues, Eggs, and Hatchling Chickens

The concentrations and enantiomer fractions (EFs) of α-, β-, and γ-hexabromocyclododecanes (HBCDs) were measured in chicken diet sources (soil and chicken feed), home-raised adult chicken (Gallus domesticus) tissues, eggs during incubation, and hatchling chicken tissues. HBCD concentrations were not detected-0.69 ng/g dry weight (dw) and 25.6-48.4 ng/g dw in chicken feed and soil, respectively. HBCDs were detected in all adult chicken tissues, except the brain, at median levels of 13.1-44.0 ng/g lipid weight (lw). The proportions of α-HBCD in total HBCDs increased from 51% in soil to more than 87% in adult chicken tissues. The accumulation ratios (ARs) of α-HBCD from diet to adult chicken tissues were 4.27 for liver, 11.2 for fat, and 7.64-12.9 for other tissues, respectively. The AR and carry-over rate (COR) of α-HBCD from diet to eggs were 22.4 and 0.226, respectively. The concentrations of α-HBCD in hatchling chicken liver (median: 35.4 ng/g lw) were significantly lower than those in hatchling chicken pectoral muscle (median: 130 ng/g lw). The EFs of α-HBCD decreased from soil to adult chicken tissues and from eggs to hatchling chicken liver. Meanwhile, the EFs of γ-HBCD increased from soil to adult chicken tissues. These results indicate the preferential enrichment of (-)-α-HBCD and (+)-γ-HBCD in chickens. The alteration of diastereoisomeric and enantiomeric patterns of HBCDs might be influenced by the different absorption and elimination rates of the six HBCD enantiomers as well as variations in HBCD metabolism in chickens.

Assessment of dietary exposure to organohalogen contaminants, legacy and emerging flame retardants in a Norwegian cohort

Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), emerging halogenated flame retardants (EHFRs) and organophosphate flame retardants (PFRs) were detected in 24h duplicate diet samples from a Norwegian cohort (n=61), with concentrations ranging from <method limit of quantification (MLQ)-0.64ng/g ww, <MLQ-0.70ng/g ww, <MLQ-0.93ng/g ww, <MLQ-0.14ng/g ww, and <MLQ-150ng/g ww, respectively. All studied contaminants were detected in the duplicate diet samples with detection frequencies (DF) ranging from 1.6 to 98%. The major contaminants were CB153 (median 0.042ng/g ww), α-HCH (median 0.22ng/g ww), BDE209 (median 0.45ng/g ww), ethyl hexyl diphenyl phosphate (EHDPHP) (median 3.0ng/g ww) and bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP) (<MLQ-0.14ng/g ww). Human dietary exposure assessment was conducted for each participant based on individual body weight and contaminant concentrations in their collected duplicate diet samples. The estimated median (95th percentile) dietary exposures for ΣPFR, ΣPCB, ΣOCP, ΣPBDE, and ΣEHFR were 87 (340), 5.8 (27), 11 (31), 1.3 (14), and <0.01 (3.4) ng/kgbw/day, respectively. The median and 95th percentile dietary exposures of most of the target analytes did not exceed the reference dose (RfD), except for PCBs where 16% of the participants exceeded the RfD. However, a relatively short period of such high intake is not expected to result in any adverse health effects. Participants of this cohort were exposed to higher levels of EHDPHP than any other FRs. Fish was the major dietary route for PCB, OCP and PBDE exposure, while meat was the main dietary exposure route for PFRs.

Home produced eggs: An important pathway of human exposure to perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) around a fluorochemical industrial park in China

Dietary intake is considered to be a major pathway of human exposure to perfluoroalkyl acids (PFAAs). Chicken egg is an important contributor to the Chinese diet. In the present study, PFAAs in home produced eggs (HPEs) and commercially produced eggs (CPEs) surrounding a fluorochemical industrial park (FIP) in China were investigated. PFAAs in HPEs decreased with increasing distance from the FIP. HPEs were much more contaminated than CPEs, with PFAAs in CPEs comparable to or lower than those in HPEs from 20km away from the FIP. PFOA concentrations in HPEs were higher than the levels of PFOA in eggs from other studies reported so far. For the first time, PFBA was reported in eggs and detected in all egg samples. PFOA and PFBA were the predominant forms in HPEs, while PFOA, PFBA and PFOS dominated in CPEs. For PFOA, estimated daily intakes (EDI) were 233ng/kg·bw/day for adults and 657ng/kg·bw/day for children who consume HPEs at households about 2km away from the FIP. The EDI of PFOA for children via HPEs exceeded the reference dose value (333ng/kg·bw/day) proposed by the Environmental Working Group.

Detoxification effects of phytonutrients against environmental toxicants and sharing of clinical experience on practical applications

According to the Food and Health Bureau and Trade and Industry Department of the Hong Kong Government, 90 % of the total food supply in Hong Kong was imported from the Mainland China. In addition, the hidden or illegal use of prohibited pesticides, food adulteration (e.g., using industrial salt in food processing, using gutter oil as cooking oil), and pollutions were periodically reported by the media. Excessive exposure to toxic heavy metals or persistent organic pollutants (POPs) from diet or environmental is inevitable amid industrialization and pollution. Understanding of the detoxification ability among nutrients in plant-based food (i.e., phytonutrients in green tea, onion, garlic, coriander, and turmeric) offers therapeutic and preventive effects against the poisoning effects due to these pollutants. Oxidative stress and pro-inflammatory actions are the common mechanisms for heavy metals or POPs toxicities, while phytonutrients counteracts these cellular insults by anti-oxidation, upregulation of anti-inflammatory pathways, and chelation.

Trophic transfer of hexabromocyclododecane in the terrestrial and aquatic food webs from an e-waste dismantling region in East China

Trophic transfer of hexabromocyclododecane (HBCD) was investigated in both the terrestrial and aquatic food webs from an e-waste dismantling region in East China. The mean Σ₃HBCD concentrations in the terrestrial species varied from 0.91 (0.16-1.85) ng g^-1 lipid weight (lw) in dragonflies (Pantala flavescens) to 40.3 (22.1-51.1) ng g^-1 lw in rats (Rattus norvegicus). The isomeric profile indicated that α-HBCD presented a decreasing trend along the trophic level (TL) (from 97.2% to 16.3% of Σ₃HBCDs), while γ-HBCD showed a reverse trend (from 2.8% to 73.6% of Σ₃HBCDs). The trophic magnification factor (TMF) derived from the slope of the regression line between TLs and ln-transferred Σ₃HBCDs was 0.10, suggesting a trophic dilution of HBCD in the terrestrial food web. By contrast, in the aquatic species, Σ₃HBCD concentrations varied from 5.02 (3.5-6.55) ng g^-1 lw in apple snails (Ampullaria gigas spix) to 45.9 (14.9-67.8) ng g^-1 lw in grass carps (Ctenopharyngodon idellus). α-HBCD was the dominant isomer, followed by γ-HBCD in the majority of species. A positive linear relationship was observed in the plots of ln Σ₃HBCDs versus TLs (R² = 0.81, p = 0.06). The TMF for Σ₃HBCDs was 6.36, indicating a trophic magnification of HBCD in the aquatic food web. Although these results demonstrated the distinct trophic transfer of Σ₃HBCDs in different ecosystems, further research is needed to eliminate the uncertainty of the tendencies, due to the non-significant relationship and limited species.

Novel brominated flame retardants in food composites and human milk from the Chinese Total Diet Study in 2011: Concentrations and a dietary exposure assessment

On the basis of the fifth Chinese total diet study (TDS) performed in 2011, the dietary exposure of the Chinese population to novel brominated flame retardants (NBFRs) was assessed. Six NBFRs were determined in 80 composite samples from four animal origin food groups and 29 pooled human milk samples. Based on gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS) analysis, the levels of the total NBFRs ranged from <LOD to 70.2ng/g lipid weight (lw) in food composites and from 2.48 to 23.9ng/g lw in human milk samples. Decabromodiphenyl ethane (DBDPE), with mean levels of 9.03ng/g lw in food composites and 8.06ng/g lw in human milk, was the most abundant compound in the total NBFRs. No obvious spatial distribution patterns in China were observed in food samples or human milk. The average estimated daily intake (EDI) of total NBFRs via food consumption for a "standard Chinese man" was 4.77ng/kg bodyweight (bw)/day, with a range of 0.681 to 18.9ng/kgbw/day. Meat and meat products were the main dietary source of NBFRs, although levels of NBFRs in aquatic food were found to be the highest among the four food groups. The average EDI of total NBFRs for nursing infants was 38.4ng/kgbw/day, with a range of 17.4 to 113ng/kgbw/day, which was approximately eight-fold higher than the EDI for adults, suggesting the heavy body burden of NBFRs on nursing infants. The levels and EDI of DBDPE in the present study were similar to or higher than those of legacy BFRs (i.e., PBDEs and HBCD) in the TDS 2007, indicating that DBDPE, as a main alternative to PBDEs, might have become the primary BFR used in China.

Habitat- and species-dependent accumulation of organohalogen pollutants in home-produced eggs from an electronic waste recycling site in South China: Levels, profiles, and human dietary exposure

Organohalogen pollutants (OHPs) including chlorinated paraffins (CPs), polybrominated diphenyl ethers (PBDEs) and other halogenated flame retardants (OHFRs) (dechlorane plus (DP), decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), hexabromobenzene (HBB), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA)) originating from an e-waste recycling area in Guiyu, southern China were investigated in chicken and goose eggs. As expected, OHP concentrations were higher in chicken eggs collected from the location (site 1) approaching the e-waste recycling center than from the location (site 2) far from the e-waste recycling center. Also, much higher OHP levels were observed in goose eggs foraging in residential area (site 2) than that in agricultural area (site 1), suggesting a clear habitat dependent OHP bioaccumulation pattern both concerning distance from e-waste activities and type of foraging habitat. Goose eggs exhibited higher short chain chlorinated paraffins (SCCPs) concentrations but lower PBDE and OHFR levels than chicken eggs. The proportion of high brominated PBDEs (hepta-to deca-BDEs) was lower in goose eggs than that in chicken eggs and showed a clear decrease from site 1 to site 2. DP isomeric composition fanti values (the ratio of the anti-DP to the sum of the anti- and syn-DP) in goose eggs were significantly lower than those in chicken eggs (p < 0.001). These differences are likely a reflection of factors such as the species-specific differences in habitat preference and the differing environmental behaviors of the pollutants owing to their inherent properties (such as solubility and vapor pressure). Our findings suggested a high dietary intake of OHPs via home-produced eggs. For BDE99 there is a potential health concern with respect to the current dietary exposure via eggs.