Dechlorane Plus Research Articles

Evidence of polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs) in wild fish species from the remote tropical marine environment, South China Sea

Polybrominated diphenyl ethers (PBDEs) and their alternatives (e.g., dechlorane plus (DPs) and decabromodiphenyl ethane (DBDPE)) are ubiquitous in various environmental media. However, limited data is available on these chemicals in edible fish species from the wide-open South China Sea (SCS). In the present study, ten legacy PBDEs and three substitutions (DBDPE and two DPs) were analyzed in 16 wild fish species sampled from the open SCS to investigate their spatial and species-specific variations. The results showed that the total concentrations of PBDEs, DBDPE, and DPs in fish samples were in the range of 1.69 to 47.6, not detected (nd) to 21.0, and nd to 3.80 ng/g lipid weight (lw), respectively. BDEs 47, 209 and 100 were the dominant target PBDE congeners, representing 49.2%, 17.2% and 9.93% of the total PBDE concentrations, respectively. Higher concentrations of PBDEs, DBDPE, and DPs were found in fish species from the Wanshan Archipelago compared to those from the Mischief Reef and the Yongxing Island, suggesting the significant influence of anthropogenic activities. Species-specific differences in levels of PBDEs were observed, with the order of bathydemersal > demersal > pelagic ≈ reef-associated > benthopelagic species. The average fanti value of all fish samples was 0.68, suggesting commercial DP products as a contamination source. The levels of PBDEs, DPs, and DBDPE in fish samples were relatively low compared with those from other locations around the globe. Finally, the health risks concerning the ingestion of BDEs 47, 99, 153 and 209 via fish consumption collected from the SCS are negligible.

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.

Comprehensive inventory of imports of electrical and electronic equipment and related plastics and POPs plastic additives into Nigeria in the past 32 years (1990–2022)

The global management of electrical and electronic equipment (EEE) and related plastics, and the persistent organic pollutants (POPs) contained in it constitute a global challenge in particular for low-income countries in Africa where monitoring capacity and waste management infrastructure are lacking. While plastic recycling is highlighted as an important part of the solution to plastic pollution, such recycling is threatened by the presence of POPs. Overall, there is a lack of data on POPs in (W)EEE plastics with the exception of PBDEs. The objective of this study was to analyse the overall imports of (W)EEE into Nigeria and estimate the associated amount of plastics and POPs for better planning and management of WEEE plastics. This study assessed all EEE importation categories and compiled the importations of 28 EEE product groups with the highest importation, covering more than 98 % of officially imported EEE based on the United Nations Comtrade Database using harmonized system (HS) codes. The impact factors of POPs and plastic from the UNEP inventory guidance were used for the estimates. Overall, 4568 kilo-tonnes (kt) of EEE were officialy imported between 1990 and 2022 containing 1337 kt of plastic. If considering also the estimated imported WEEE and EEE not covered in the Comtrade statistics, the total imported (W)EEE is estimated to 12,259 kt including 3644 kt of plastics and an estimated 1043 t of hexaBDE/heptaBDE and 8511 t of DecaBDE as major POP additives, and lower levels of 154 t of HBCD, 91 t of SCCPs, 364 t of MCCP, and 146 t of Dechlorane Plus. The study is the first estimate of all major POPs in (W)EEE plastics in a low-income country and provides important information for their management.

Distribution and co-occurrence of microplastics and co-existing pollutants in bottom water and sediment of the East China Sea

Microplastics (MPs) contamination in marine environment has been an emerging issue worldwide, notably due to the potential ecological risks of MPs with co-existing environmental contaminants and released toxic plastic additives. To verify the co-occurrence characteristics of MPs and co-existing pollutants in the benthic boundary layer (BBL), the distribution characteristics of MPs, and selected heavy metals (HMs) and halogenated flame retardants (Polybrominated diphenyl ethers, PBDEs, and Dechlorane Plus) in the bottom water and sediment were comprehensively investigated in the East China Sea (ECS). The sampling sites were selected along the coast of ECS, where might be significantly affected by terrigenous inputs and anthropogenic sources. MPs were abundant in the bottom water (62.8–480.2 items/L) and sediment (80.1–1346.7 items/kg d.w.) with polyester, polyethylene, and polypropylene being as the most abundant types and characterized as fiber/line, particle size 200–500 μm, and transparent/white. The abundance and characteristics of MPs demonstrated strong correlations within the bottom water and sediment, which might be due to the frequent exchange of materials. In addition, the abundance of MPs was significantly positively correlated with HMs (Cd, Cr, Pb) in the bottom water and PBDEs in sediment, respectively. According to the scanning electron microscopy/energy dispersive X-ray spectrometry analysis, MPs might act as carriers to transport and co-sediment the co-existing pollutants in water, and physically adsorb or chemically bind with pollutants in sediment. These results could help to elucidate the sources, migration, and fate, and verify the occurrence and potential risks of MPs and their co-existing pollutants in BBL, thus realize the management and control of MPs contamination in marine.

Dechlorane plus in dust, hair and urine: Exposure, excretion and level change

Dechlorane plus (DP) has been detected in a variety of environmental media and in human. Measurement of DPs in hair, urine, and house dust across different habitats allows for the assessment of short-term spatial changes in human exposure to DPs, as well as their excretion in urine. This offers a significant reference point for further research on the behavior of persistent pollutants within organisms. We measured and analyzed the concentrations of DP in the hair and urine of 32 students from a university in Beijing during school and home phases, and in indoor dust from dormitories and some home environments. The results indicated that the concentrations of DP in three types of samples were higher during the home phase compared to the school phase. We compared the fanti values and identified selective enrichment of syn-DP in hair, along with selective excretion of syn-DP in urine. Utilizing molecular docking technique, we simulated the binding effect between DP and the Megalin protein. The results demonstrated that the binding energy of anti-DP to Megalin was higher than that of syn-DP, suggesting that anti-DP has a greater propensity to bind to Megalin and be reabsorbed. This results in higher levels of syn-DP excretion in urine. Finally, we categorized students based on their participation in the organic exposure experiment and their BMI. The results indicated that the concentrations of DP in hair and urine were higher in the exposed group compared to the non-exposed group during the school year. After excluding the effect of exposure, habitat changes were more likely to affect the accumulation and excretion of DP in normal-weight students (BMI ≤24 kg/m2, n = 28), while overweight students (BMI >24 kg/m2, n = 4) were less affected by the effect of habitat because of their higher body fat percentage and their greater ability to accumulate DP.

Identification of ∼200 transformation products of polyhalogenated compounds to characterize their transformation pathways in sludges

Sewage sludge adsorbs a large amount of harmful organic pollutants, particularly the persistent and hydrophobic polyhalogenated compounds (PHCs). PHCs have been subjected to biological and chemical oxidation treatments during wastewater treatment processes; however, the species and concentrations of their transformation products (TPs) in sludge remain unknown, and the transformation pathways are unclear. In this study, 234 TPs of PHCs, including 77 TPs of chlorinated paraffins (CPs-TPs), 102 TPs of organochlorine pesticides (OCPs-TPs), 45 TPs of dechlorane plus (DPs-TPs), and 10 TPs of brominated flame retardants (BFRs-TPs), were identified in sludge through Ph4PCl-enhanced ionization coupled with ultra-performance liquid chromatography–Orbitrap–mass spectrometry. Based on the chemical structures of the identified TPs, we identified three major transformation pathways: dehalogenation-hydroxylation, carbon chain decomposition, and desulfurization. Approximately 97 TPs were newly discovered through the pathways. Carbon chain decomposition products of OCPs and DPs were detected for the first time at relatively high abundances. More hydroxylation products of DPs and hexabromocyclododecane (HBCD) and multi-dehalogenation products of heptachlor, toxaphene, DPs and HBCDs were detected at relative intensities higher than those of the known TPs. The oxidation treatment of sludge achieved up to 13 %–94 % of PHCs to be removed, with dehalogenation-hydroxylation as the main transformation pathway. Advanced treatment technologies are needed for degradation of both PHCs and their TPs.

Differences in Toxicokinetics and Maternal Transfer between Lipophilic and Proteinophilic Halogenated Organic Pollutants in Laying Hens.

In this study, we conducted exposure experiments on egg-laying hens to explore the toxicokinetics and maternal transfer characteristics of lipophilic and proteinophilic halogenated organic pollutants (HOPs). The lipophilic HOPs included polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dechlorane plus (DPs), while the proteinophilic HOPs included perfluorocarboxylic acids (PFCAs). The results revealed that most of lipophilic HOPs exhibit lower depuration rate (k d) than PFCAs. The k d of lipophilic HOPs correlated with the octanol-water partition coefficient (log K OW) values in a V-shaped curve, whereas that of PFCAs correlated with the protein-water partition coefficient (log K PW) values in an inverted V-shaped curve. The depuration rate, rather than the uptake rate, was a leading factor in determining the bioaccumulation potential of HOPs in hens. Although the dominant factors determining the tissue distribution of the two types of compounds were explicit (fats vs phospholipids), chemical-specific tissue distribution was still observed. The egg-maternal concentration ratio was dependent on the exposure status, concentration, and maternal tissue choice. Using a single maternal tissue may not be an appropriate method for assessing chemical maternal transfer potential. PFCAs have a greater maternal transfer potential (>80% of the total body burden) than lipophilic HOPs (approximately 30% for BDE209 and DPs, and less than 10% for the others). Their lipophilic and partly proteinophilic nature makes the toxicokinetics and maternal transfer characteristics of BDE209 and DPs different from those of other lipophilic HOPs. These findings are crucial for enhancing our understanding of the behavior and fate of HOPs in egg-laying hens.

Characterizing the effects of Dechlorane Plus on β-cells: a comparative study across models and species

ABSTRACT Epidemiological studies consistently link environmental toxicant exposure with increased Type 2 diabetes risk. Our study investigated the diabetogenic effects of a widely used flame retardant, Dechlorane Plus (DP), on pancreatic β-cells using rodent and human model systems. We first examined pancreas tissues from male mice exposed daily to oral gavage of either vehicle (corn oil) or DP (10, 100, or 1000 μg/kg per day) and fed chow or high fat diet for 28-days in vivo. DP exposure did not affect islet size or endocrine cell composition in either diet group. Next, we assessed the effect of 48-hour exposure to vehicle (DMSO) or DP (1, 10, or 100 nM) in vitro using immortalized rat β-cells (INS-1 832/3), primary mouse and human islets, and human stem-cell derived islet-like cells (SC-islets). In INS-1 832/3 cells, DP did not impact glucose-stimulated insulin secretion (GSIS) but significantly decreased intracellular insulin content. DP had no effect on GSIS in mouse islets or SC-islets but had variable effects on GSIS in human islets depending on the donor. DP alone did not affect insulin content in mouse islets, human islets, or SC-islets, but mouse islets co-exposed to DP and glucolipotoxic (GLT) stress conditions (28.7 mM glucose + 0.5 mM palmitate) had reduced insulin content compared to control conditions. Co-exposure of mouse islets to DP + GLT amplified the upregulation of Slc30a8 compared to GLT alone. Our study highlights the importance and challenges of using different in vitro models for studying chemical toxicity.

Dechloranes and chlorinated paraffins in sediments and biota of two subarctic lakes.

Our understanding of the environmental behavior, bioaccumulation and concentrations of chlorinated paraffins (CPs) and Dechloranes (Dec) in the Arctic environment is still limited, particularly in freshwater ecosystems. In this descriptive study, short chain (SCCPs) and medium chain (MCCPs) CPs, Dechlorane Plus (DP) and analogues, and polychlorinated biphenyls (PCBs) were measured in sediments, benthic organisms, three-spined stickleback (Gasterosteus aculeatus), Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) in two Sub-Arctic lakes in Northern Norway. Takvannet (TA) is a remote lake, with no known local sources for organic contaminants, while Storvannet (ST) is situated in a populated area. SCCPs and MCCPs were detected in all sediment samples from ST with concentration of 42.26-115.29ng/g dw and 66.18-136.69ng/g dw for SCCPs and MCCPs, respectively. Only SCCPs were detected in TA sediments (0.4-5.28ng/g dw). In biota samples, sticklebacks and benthic organisms showed the highest concentrations of CPs, while concentrations were low or below detection limits in both char and trout. The congener group patterns observed in both lakes showed SCCP profiles dominated by higher chlorinated congener groups while the MCCPs showed consistency in their profiles, with C14 being the most prevalent carbon chain length. Anti- and syn-DP isomers were detected in all sediment, benthic and stickleback samples with higher concentrations in ST than in TA. However, they were only present in a few char and trout samples from ST. Dec 601 and 604 were below detection limits in all samples in both lakes. Dec 603 was detected only in ST sediments, sticklebacks and 2 trout samples, while Dec 602 was the only DP analogue found in all samples from both lakes. While there were clear differences in sediment concentrations of DP and Dec 602 between ST and TA, differences between lakes decreased with increasing δ15N. This pattern was similar to the PCB behavior, suggesting the lake characteristics in ST are playing an important role in the lack of biomagnification of pollutants in this lake. Our results suggest that ST receives pollutants from local sources in addition to atmospheric transport.

The emerging and legacy persistent organic contaminants in corals of the South China Sea

Seawater warming, ocean acidification and chemical pollution are the main threats to coral growth and even survival. The legacy persistent organic contaminants (POCs), such as polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), and the emerging contaminants, including polybrominated diphenyl ethers (PBDEs), dechlorane plus (DPs) and novel brominated flame retardants (NBFRs) were studied in corals from Luhuitou fringing reef in Sanya Bay and Yongle atoll in Xisha Islands, the South China Sea (SCS). Total average concentrations of ∑16PAHs, ∑23OCPs, ∑34PCBs, ∑8PBDEs, ∑2DPs and ∑5NBFRs in 20 coral species (43 samples) from the SCS were 40.7 ± 34.6, 5.20 ± 5.10, 0.197 ± 0.159, 3.30 ± 3.70, 0.041 ± 0.042 and 36.4 ± 112 ng g−1 dw, respectively. PAHs and NBFRs were the most abundant compounds and they are likely to be dangerous pollutants for future coral growth. Compared to those found in other coral reef regions, these pollutants concentrations in corals were at low to median levels. Except for PBDEs, POCs in massive Porites were significantly higher than those in branch Acropora and Pocillopora (p < 0.01), as large, closely packed corals may be beneficial for retaining more pollutant. The current study contributes valuable data on POCs, particularly for halogenated flame retardants (HFRs, including PBDEs, DPs and NBFRs), in corals from the SCS, and will improve our knowledge of the occurrence and fate of these pollutants in coral reef ecosystems.

Historical Occurrence and Composition of Novel Brominated Flame Retardants and Dechlorane Plus in Sediments from an Electronic Waste Recycling Site in South China.

Novel brominated flame retardants (NBFRs) and dechlorane plus (DP) have been widely used as alternatives to traditional BFRs. However, little is known about the temporal trends of NBFR and DP pollution in e-waste recycling sites. In the current study, three composite sediment cores were collected from an e-waste-polluted pond located in a typical e-waste recycling site in South China to investigate the historical occurrence and composition of NBFRs and DP. The NBFRs and DP were detected in all layers of the sediment cores with concentration ranges of 5.71~180,895 and 4.95~109,847 ng/g dw, respectively. Except for 2,3,5,6-tetrabromo-p-xylene (pTBX) and 2,3,4,5,6-pentabromoethylbenzene (PBEB), all the NBFR compounds and DP showed a clear increasing trend from the bottom to top layers. These results implied the long-term and severe contamination of NBFRs and DP. Decabromodiphenyl ethane (DBDPE) was the most abundant NBFR with the contribution proportions of 58 ± 15%, 73 ± 15%, and 71 ± 18% in three sediment cores, followed by 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) and pentabromobenzene (HBB). The ratios of BTBPE/Octa-BDEs and DBDPE/Deca-BDEs varied from 0.12 to 60 and from 0.03 to 0.49, respectively, which had no clear increase trends with a decrease in sediment depth. As for DP, the fanti values (the concentration ratios of anti-DP to the sum of anti-DP and syn-DP) in sediment cores ranged from 0.41 to 0.83, almost falling in the range of those in DP technical products, suggesting that DP degradation did not occur in sediment cores. The environmental burdens of DBDPE, BTBPE, HBB, PBT, PBEB, pTBX, and DP were estimated to be 34.0, 5.67, 10.1, 0.02, 0.02, 0.01, and 34.8 kg, respectively. This work provides the first insight into the historical contamination status of NBFRs and DP in the sediments of an e-waste recycling site.

Dechlorane Plus in environmental samples and human serum samples from new and old electronic waste dismantling areas in East China: Levels, composition profiles, and human exposure

The global presence of Dechlorane Plus (DP) in environmental and human samples highlights the need for further research into its ecological risks and health effects. This study determined DP concentrations in soil and air samples from an old electronic waste dismantling area (Fengjiang) and a new electronic waste dismantling area (Binhai) in Taizhou City, China. Both syn-DP and anti-DP isomers were found in all soil and air samples. The median concentrations of DP in soil and air were 90.5 ng/g and 48.4 pg/m3 in Fengjiang, and 6.69 ng/g and 28.8 pg/m3 in Binhai. DP were widespread in the local environment, and in general at moderate levels compared with reports from other electronic waste dismantling areas. The analysis of DP isomer profiles in different seasons and the calculation of related fugacity fraction showed that anti-DP perhaps easier than syn-DP to migrate from soil to air in summer. DP concentrations in serum of residents from Fengjiang (median 9.74 ng/g) were significantly higher than those from Huangyan (common control area, median 2.77 ng/g; p < 0.01), while the fanti value showed that Fengjiang was significantly lower than Huangyan (p < 0.05). This revealed that DP exposure levels in serum perhaps one of the crucial factors influencing fanti value. Moreover, DP concentrations in serum showed an increasing trend with increasing body mass index (BMI) or age. However, the relationship between DP and sex was not observed. The fanti values of serum samples were higher than those in soil and air samples, suggested that DP perhaps stereo-selectively absorbed into the body or stereo-selectively metabolised.

The interfacial interaction between Dechlorane Plus (DP) and polystyrene nanoplastics (PSNPs): An overlooked influence factor for the algal toxicity of PSNPs

As pollution has attracted attention due to its wide distribution. An environmental concern that may be overlooked is that NPs additives are easily released into the environment due to their physical combination with NPs. However, the knowledge gaps still exist about the interfacial reactions of NPs and the additives (e.g. flame retardants) and the joint ecological effect. In the present study, fourier transform infrared (FTIR) spectrometer coupled with 2D correlation spectroscopy (2D-COS) analysis revealed the interfacial reactions between polystyrene nanoplastics (PSNPs) and Dechlorane Plus (DP). Results showed that carbon‑oxygen bonds and carbon‑chlorine bonds were the important binding sites during adhesion and DP could reduce the colloidal stability. Single and joint ecological effects of PSNPs and DP on the microalgae Chlorella vulgaris were further deliberated. Reduced photosynthetic efficiency (reduced Fv/Fm by 0.03 %), higher growth inhibition (16.15 %) and oxidative damage (increased ROS by 152 %) were observed in algae under co-exposure. Notably, DP could significantly increase the attachment of PSNPs to the surface of the algae. Metabolomics further revealed that co-exposure significantly down-regulated amino acid metabolism and tricarboxylic acid cycle (TCA) cycle, and up-regulated fatty acid metabolism. The present study provides new insights into the risk assessment of NPs in aquatic environment by investigating the interfacial reaction mechanism and combined ecotoxicity of NPs and additives.

Two halogenated flame retardants and cadmium in the soil-rice system: sorption, root uptake, and translocation.

The migration and transformation of Tetrabromobisphenol A (TBBPA), DechloranePlus (DP), and cadmium in soil-rice system was investigated, and the influence on the quality of two varieties of rice was studied. The degradation half-lives of TBBPA, BBPAs, syn-DP, and anti-DP were 23.18 ~ 26.36days, 30.14 ~ 36.10days, 72.96-81.55days, and 169.06-198.04days in the soil. TBBPA was gradually degraded to tri-BBPA, di-BBPA, mono-BBPA, and bisphenol A by the debromination. TBBPA and its bromide metabolites could be bioaccumulated in different tissues of rice; mono-BBPA and bisphenol A was easy to accumulate in the stems, and bisphenol A was easy to bioaccumulate in the grain. Comparing with single and compound pollution, there was no significant difference in bioaccumulation factors of two rice species. The grain of NO7 had stronger bioaccumulation ability to mono-BBPA and BPA than NO1, and there is no significant difference in TBBPA. Residual level of DP in the rice: roots > stems > grain; there was no significant difference in bioaccumulation of two varieties of rice. Cadmium was easily bioaccumulated in the roots of rice and translocated to the rice stems and grains. NO7 rice had stronger bioaccumulation and transport capacity than NO1. The effects of the three pollutants on the quality of two varieties of rice varied significantly; cadmium had the greatest effect on the iodine blue value (BV) and amylase activity of the grain. This study proved that selecting rice varieties with low bioaccumulation to polluters can effectively reduce the risk of the food chain harming human health.

2 plastics additives, insecticide face global ban

Delegates from around the world have agreed to add two plastics additives and a pesticide to the Stockholm Convention on Persistent Organic Pollutants, an international treaty that lists toxic substances for global elimination. The agreement was reached during a 2-week meeting that wrapped up May 12 in Geneva. The two plastics chemicals are the flame retardant Dechlorane Plus and the ultraviolet stabilizer UV-328. The targeted pesticide is methoxychlor. All three chemicals meet the criteria for inclusion in the treaty: they are persistent, bioaccumulative, and harmful to human health and the environment, the delegates found. Environmental advocates welcome the decision to add the three chemicals to the Stockholm Convention but point out that exemptions will allow continued use of the plastics additives. The agreement is an important step “toward protecting human health and the environment from three chemicals linked to serious health conditions and threats to biodiversity,” Sara Brosché, a science

Socio-Economic Factors Impact US Dietary Exposure to Halogenated Flame Retardants.

Although diet is an important route of exposure for brominated flame retardants (BFRs), little is known of their presence in US food. Therefore, we purchased meat, fish, and dairy product samples (n = 72) in Bloomington, IN, from 3 stores representing national retail chains at different price levels. Composite samples (n = 42) were analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), novel BFRs (NBFRs), and dechlorane plus (DP). Concentrations of total halogenated flame retardants (HFRs) ranged between 54 and 1,400 pg/g ww, with PBDEs being the predominant compounds. Concentrations of NBFRs, but not PBDEs, in US food items were significantly impacted by price, raising the issue of environmental justice. Nonorganic food generally had a higher abundance of BDE-209 than organic food items. Estimates of dietary exposure revealed that meat and cheese consumption contribute most to the overall HFR intake and that intakes are highest for children and for non-Hispanic Asians. Taking into account several caveats and limitations of this study, these results as a whole suggest that health burdens from dietary exposure to HFRs have become minimal for US citizens, highlighting the positive impact of regulatory efforts.

Effects of polystyrene microplastics on dechlorane plus bioaccumulation in the thick-shell mussel

The combined pollution of microplastics (MPs) and persistent organic pollutants (POPs) have attracted increasing attention from the international community in recent years. MPs can affect the toxicity, bioenrichment rate and bioavailability of POPs through adsorption and other interactions. Dechlorane Plus (DP) is a chlorinated flame retardant and a typical. DPs used mainly in various polymer materials, such as electrical wire and cable coating. The pollutions of MPs and DPs (syn and anti isomers, syn-DP [s-DP] and anti-DP [a-DP]) are ubiquitously present in the environment. However, the effect of MPs on the bioaccumulation of DP has not been reported. In this study, thick-shell mussels (Mytilus coruscus) were exposed to DPs (10 ng/L, DP10), DPs and polystyrene microplastics (PS) (10 ng/L DP +10 μg/L PS, DP10/PS10; 10 ng/LDP+20 μg/L PS, DP10/PS20) for 28 days to investigate the effect of MPs on DPs enrichment. Thick-shell mussels accumulated DPs in the adductor muscle, gill, and gonad showed an increasing trend with time, but the concentration of DPs in the visceral mass does not show a time-dependent manner. The concentration of DPs in the gonads and gills was significantly affected by the concentration of PS (p &amp;lt; 0.05), but there was no significant correlation between the concentration of DPs and the concentration of PS in the adductor muscle and visceral mass (p &amp;gt; 0.05). Moreover, DPs showed selective enrichment of syn-DP in thick-shell mussel tissues, and there was no significant correlation between this result and PS concentration (p &amp;gt; 0.05). These findings provide a new entry point for studying the interaction between microplastics and persistent organic pollutants in marine organisms.

Emission and gas-particle partitioning characteristics of atmospheric halogenated and organophosphorus flame retardants in decabromodiphenyl ethane-manufacturing functional areas

The emission and gas-particle partitioning characteristics in various functional areas of production lines are still unknown. However, flame-retardant manufacturing activities are the primary emission source of flame retardants. Thus, fine particles and gases were investigated in three functional areas of a decabromodiphenyl ethane production line, i.e., polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), dechlorane plus (DPs), and organophosphorus flame retardants (OPFRs) in a flame-retardant manufacturing factory. High levels of PBDEs (8.02 × 103–4.16 × 104 pg/m3), NBFRs (6.05 × 103–1.92 × 105 pg/m3), and DPs (89.5–5.20 × 103 pg/m3) were found in various functional areas, suggesting manufacturing activities were a primary emission source. In contrast, OPFRs were derived from long-range transport or other non-industrial sources. Varied concentrations of PBDEs, NBFRs, and DPs were observed in different production lines, higher in the reaction zone area than others. As the predominant compounds, decabromodiphenyl ether, decabromodiphenyl ethane, syn-DP, and tris(chloropropyl) phosphate accounted for 54.7%, 89.3%, 93.4%, and 34.7% of PBDEs, NBFRs, DPs, and OPFRs, respectively. Three models were used to predict the gas-particle partitioning of the halogenated flame retardants emitted from manufacturing activities. The Li-Jia Empirical Model predicted the gas-particle partitioning behavior well. This research shows that the adsorption-desorption process of the halogenated flame retardants between the gaseous and particulate phases did not reach equilibrium.

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.

Aging affects isomer-specific occurrence of dechlorane plus in soil profiles: A case study in a geographically isolated landfill from the Tibetan Plateau

Two major structural isomers in commercial dechlorane plus (DP) mixtures, anti-DP and syn-DP, generally displayed varied desorption and partitioning efficiencies in soils, which may be linked to their different aging rates. However, the molecular parameters that govern the degree of aging and its associated effects on the occurrence of DP isomers have not been comprehensively investigated. In this study, the relative abundance of rapid desorption concentration (Rrapid) was measured for anti-DP, syn-DP, anti-Cl11-DP, anti-Cl10-DP, Dechlorane-604 (Dec-604), and Dechlorane-602 (Dec-602) at a geographically isolated landfill area in the Tibetan Plateau. The Rrapid values were used as an indicator of aging degree, exhibiting a close correlation with the three-dimension conformation of the molecules for the dechlorane series compounds. This observation suggested that planar molecules may have a greater tendency to accumulate in the condensed phase of organic matter and undergo more rapid aging. The fractional abundances and dechlorinated products of anti-DP were found to be predominantly controlled by the aging degree of DP isomers. The multiple nonlinear regression model indicated that differences in aging between anti-CP and syn-DP were primarily driven by the total desorption concentration and soil organic matter content. Aging plays a significant role in both the transport processes and metabolism of DP isomers and should be taken into account to refine the assessment of their environmental behaviors.