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China, one of the two dechlorane plus (DP) producers, might have become a major area of DP pollution. The environmental contamination status of DP in sediments across the whole of China has not yet been studied. In the current study, the pollution levels, spatial distribution, and compositions of DP were investigated comprehensively in surface sediments from 173 black-odorous urban rivers across China for the first time. Total DP concentrations varied from not-detected to 39.71 ng/g dw, with an average concentration of 3.20 ± 4.74 ng/g dw, which was polluted by local emission sources and presented significant differences among different sampling cities. Among the seven administrative regions of China, DP concentrations were the highest in South China and showed a decreasing trend from southeastern coastal areas to northwest inland regions. Spearman's correlation analysis suggested that the gross industrial output, gross domestic product, and daily wastewater treatment capacity were not the principal factors controlling the spatial distribution of DP. The fanti values (the concentration ratios of anti-DP to the sum of anti-DP and syn-DP) varied from 0.19 to 0.88, with those in most sediments falling in the range of DP technical product (0.60 ~ 0.80), suggesting no apparent stereoselective enrichment occurred. Moreover, the anti-Cl11-DP was detected in sediments (n.d. ~ 0.40 ng/g dw), which showed significantly and insignificantly positive correlation with the anti-DP levels and fanti, respectively, implying it might mainly originate from the byproduct of DP technical product rather than the dechlorination of anti-DP. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 ~ 26.36 days, 30.14 ~ 36.10 days, 72.96–81.55 days, and 169.06–198.04 days 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. [ABSTRACT FROM AUTHOR]

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.

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 < 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 > 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 > 0.05). These findings provide a new entry point for studying the interaction between microplastics and persistent organic pollutants in marine organisms.

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 f anti 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. [Display omitted] • Dechlorane Plus (DP) concentration levels in dust, hair, and urine vary significantly between school and home environments. • Hair samples can effectively reflect changes in DP levels in the human body due to short-term variations in exposure environments. • Anti-DP is selectively reabsorbed by the body and more likely to bind to Megalin proteins, resulting in lower concentrations in urine compared to syn-DP. • Multiple exposure pathways primarily influence the overall DP levels in the body, with minimal impact on the selective enrichment and excretion capacities. [ABSTRACT FROM AUTHOR]

E-waste recycling employees represent a specific population with a high potential for exposure to dechlorane plus (DP). However, the impact of skin-adherent DP on human exposure within this group has not been well characterized. This study aimed to address this gap by collecting handwipe and matched serum samples (n = 86 pairs) of Chinese e-waste recycling employees. In vivo human dermal bioavailability of DP was also examined to achieve effective exposure estimation. As a result, DP was detected in all handwipe and serum samples, indicating the occurrence of widespread exposure in the study population. For all the participants, the median level of ∑DP (the sum of syn -DP and anti -DP) in the serum was 45.1 ng g−1 lipid weight (lw), while handwipe samples showed the loading of 10.8 ng per wipe. Notably, significant associations were found between DP handwipe loadings and matched serum levels (p <0.05). Next, the in vivo human dermal bioavailability was estimated to be 9.54% for ∑DP. Based on this value, the estimated average daily dose was 0.231 ng kg−1 d−1 (median values), contributing 10.9% to serum levels of ∑DP. The significant associations and 10.9% percentage contribution together underscore the non-negligible influence of dermal absorption on DP internal doses in the e-waste recycling employees. Moreover, the extremely high levels of DP (up to 3.64E+04 ng g−1 lw) detected in serum highlight the extent of DP accumulation in humans. Continuous monitoring and assessment are warranted among e-waste workers due to the persistent organic pollutant properties of DP. [Display omitted] • The non-negligible influence of dermal exposure to dechlorane plus (DP) was identified on e-waste recycling population. • The in vivo human bioavailability was estimated to be 9.54% for ∑DP by the parallelogram approach. • Unexpectedly high serum levels of DP (dozens of μg g−1 lw) was found in human beings. [ABSTRACT FROM AUTHOR]

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. [Display omitted] • E-waste processing elevates PBDEs and DP in environment, food, and human samples. • Significant contamination found in e-waste workers' blood compared to reference sites. • Medical monitoring and protective measures recommended for Kalasin e-waste workers. • Urgent environmental restoration needed at Khok Sa-ad to protect local residents. [ABSTRACT FROM AUTHOR]

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 1.69–47.6, 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 f anti 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. [Display omitted] • PBDEs, DPs, and DBDPE were ubiquitously found in fish from the open SCS. • PBDE levels in the fish from this study are low compared to fish from other parts of the world. • BDE-47 and BDE-209 were the prevalent PBDE congeners in fish species. • The bioaccumulation of PBDEs, DBDPE, and DPs in fish was species-specific. • Health risks via fish ingestion associated with target chemicals are negligible. [ABSTRACT FROM AUTHOR]

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.

Dechlorane Plus (DP) and Tetrabromobisphenol A (TBBPA) are the halogenated flame retardant with the highest production volume, cadmium (Cd) is regarded as one of the hazardous heavy metals due to its bio toxicity and bioaccumulation in the environment, and it will cause environmental pollution and affect human health, so a pot experiment was conducted to investigate the phytotoxicity on seed germination and seedling of two rice varieties. The results showed that with the increasing of DP, TBBPA and Cd concentrations in soil, the germination rate, germination index and vigor index of two rice varieties decreased, and the germination of Number 7 rice was affected more than Number 1 rice. Halogenated flame retardants and Cd in soil significantly promoted root activity and proline, and significantly inhibited protein and soluble sugar contents of two rice varieties. In addition, the responses of the two rice varieties seedlings to different pollutants were obviously different. The activity of superoxide dismutase (SOD) in two kinds of rice was improved, and a large amount of malonyldialdehyde (MDA) was induced. But the activity of catalase (CAT) in Number 7 rice was increased under the action of DP and TBBPA, while the activity of Number 1 rice was increased under the action of DP and inhibited under the pollution of TBBPA. Bioaccumulation factors of DP and Cd were 0.025–0.042 and 6.59–14.20, bio transport coefficients were 0.39–0.48 and 0.034–0.087. There was no significant difference in the bioaccumulation of DP in the two rice varieties, but TBBPA and Cd were more easily bio accumulated in the Number 1 rice. These findings would provide some essential information for interpreting the ecological risks of two halogenated flame-retardants and Cd in plants.

To develop an appropriate sampling strategy to assess the intrauterine exposure to dechlorane plus (DP), we investigated DP levels in sequential maternal blood samples collected in three trimesters of pregnancy, respectively, from women living in Taizhou. The median concentration of DPs (sum of syn-DP and anti-DP) in all samples was 30.5 pg g−1 wet-weight and 5.01 ng g−1 lipid-adjusted weight, respectively. The trimester-related DP concentrations were consistently strongly correlated (p < 0.01), indicating that a single measurement of DP levels could represent intrauterine exposure without sampling from the same female repeatedly; however, the wet-weight levels significantly increased across trimesters (p < 0.05), while the lipid-adjusted levels did not significantly vary. Notably, whether lipid-adjusted weight or wet-weight levels, the variation extent of DP across trimesters was found to be less than 41%, and those for other persistent organic pollutants (POPs) reported in the literature were also limited to 100%. The limitation in variation extents indicated that, regardless of the time of blood collection during pregnancy and how the levels were expressed, a single measurement could be extended to screen for exposure risk if necessary. Our study provides different strategies for sampling the maternal blood to serve the requirement for assessment of in utero exposure to DP. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The levels of the chlorinated organic compound Dechlorane Plus (DP) are increasing in aquatic ecosystems. To investigate the adverse effects of DP on aquatic animals, common carp (Cyprinus carpio) were subjected to three different DP concentrations (30 μg L−1, 60 μg L−1, and 120 μg L−1) for 1 d, 15 d, and 30 d. Histology and the hepatic and cerebral expression levels of several key antioxidant, detoxification, and apoptotic factors were then examined. Histopathological inspections showed that the liver and brain were severely damaged in carp exposed to 60 μg L−1 and 120 μg L−1 DP. Relative to the controls, the superoxide dismutase and glutathione activity levels and the malondialdehyde content were also changed in livers and brains exposed to DP. Besides, significant alterations in the expression levels of the inflammatory cytokines IL-1β, IL-6, and IL-10 were observed in the livers of carp subjected to DP. Relative to the control, the brains of DP-exposed carp presented with significantly upregulated IL-1β and IL-6 in carp treated with 120 μg L−1 DP for 30 d. The transcription levels of hepatic cyp2b4, cyp1b1, and cyp3a138 were all increased compared with the untreated at all DP exposure concentrations. The aforementioned results suggest that DP exposure perturbs fish metabolism and causes liver injury by inhibiting antioxidant enzyme activity, increasing lipid peroxidation, promoting inflammation, and inducing cell apoptosis. This information and the analytical methodology used to acquire it may form the basis for future ecological risk assessments on DP and related xenobiotics in aquatic animals. [ABSTRACT FROM AUTHOR]

The effect of emerging pollutant Dechlorane Plus (DPs), an organochlorine aliphatic flame retardant, on waste-activated sludge anaerobic fermentation was investigated, and the related mechanisms were revealed for the first time. The results of this experiment suggested that the presence of DPs had a significant inhibitory effect on sludge anaerobic fermentation to generate the intermediate valuable product short-chain fatty acids (SCFA), and when the DP content was 3034.1±101.7 mg/kg total suspended solids (TSS), the maximal output of SCFA was only 215.04 mg/g, which was 0.47 times of that in the blank. The underlying mechanism investigation indicated DPs promoted the disintegration of sludge, but inhibited the process of hydrolysis and acidification. DPs inhibited the release of soluble bound extracellular polymers (SB-EPS) in sludge. The analysis of microbial community characteristics indicated that DPs reduced the level of Firmicutes and Actinobacteriathe, which were the key acid producing bacteria. At the genus level, DPs reduced the relative abundance of Proteiniclasticum and Mycobacteriumwas. [ABSTRACT FROM AUTHOR]

Here, a new gas chromatography-atmospheric pressure photoionization-high-resolution mass spectrometry (GC-APPI-HRMS) method combined with selective pressurized liquid extraction (sPLE) has been developed for the selective determination of Dechlorane Plus (DP) and its related compounds in gull egg samples used as a bioindicator of contamination. To the best of our knowledge, this is the first time these compounds have been analyzed by GC-MS using atmospheric pressure photoionization (APPI). Negative ion dopant-assisted APPI using vapors of diethyl ether and a source temperature of 250 °C provided high ionization efficiencies and mass spectra characterized by intense in-source fragment ions as well as the presence of molecular ion and characteristic cluster ions containing oxygen atoms in their chemical structure. This made it possible to improve the selectivity in the determination of these compounds compared to that obtained with traditional GC-MS ion sources. Under optimized conditions, the sPLE GC-APPI-HRMS (Orbitrap) method provided high recoveries (> 91%), good precisions (RSD% < 12%), and low method limits of detection (0.1–3.5 pg g−1 wet weight). The developed methodology has been applied to the determination of DP and related compounds in eggs of two gull species (L. michahellis and L. audouinii) from several Spanish protected areas. The results obtained showed significant differences in the DP concentration profiles in eggs from different gull breeding locations and between gull species of the same protected area. These results demonstrated the good performance of the GC-APPI-HRMS system to achieve a selective and sensitive determination of DP and related compounds in complex environmental samples. [ABSTRACT FROM AUTHOR]

Dechlorane Plus (DP) is found widely in the environment. It is important to study DP enrichment and biomagnification in terrestrial ecosystems to improve our understanding of the possible effects of DP on the environment and human health. A total of 90 samples, including plant and animal tissues, were collected from Xilingol Prairie in Inner Mongolia, China. The DP concentrations in different species were assessed, and transmission of DP through food webs containing ectotherms and endotherms was assessed. The compound was detected in the biotic samples (plant; range 0.133–0.422 ng/g dry wt), in animal muscle (range: not dected–5.70 ng/g lipid wt), and in animal hair (range: not dected–2.03 ng/g dry wt), indicating that DP is present in remote environments such as Xilingol Prairie. These findings suggest that DP can undergo long‐distance transport in the environment. Biomagnification factors (ectotherms: range 0.146–88.0, endotherms: range 0.866–17.2) and anti‐DP/total DP concentration ratios (fanti values of 0.412–0.787) for the prairie animals were calculated. Ectotherms were found to selectively enrich syn‐DP, and stereoselective enrichment increased moving up the food web. Lower‐trophic‐level endotherms strongly stereoselectively enriched syn‐DP, and higher‐trophic‐level endotherms stereoselectively enriched anti‐DP. Environ Toxicol Chem 2021;40:413–421. © 2020 SETAC [ABSTRACT FROM AUTHOR]

The gut microbiota has been shown to be highly involved in many vital physiological processes that play key roles in human health. The intergenerational transfer of Dechlorane Plus (DP) and the complex interaction between DP and microbiota has been poorly studied. Additionally, the structural and functional effects of DP on the gut microbiota have not been studied. This study aimed to investigate the DP transfer in Sprague-Dawley rats during pregnancy and the effects of DP exposure on gut microbiota, as detected by 16S rRNA gene sequencing. The results showed that excretion in feces is a very important elimination pathway of orally dosed DP. The main intergenerational transfer pathway of DP might be via lactation rather than transplacental transport. The 16S rRNA sequencing revealed that DP exposure could decrease the richness and diversity of gut microbiota, especially at the genus level. Furthermore, in DP exposure groups, the gut microbiota production of metabolites of short-chain fatty acids was dramatically increased. The results demonstrated that DP exposure not only altered the gut microbiota structures, but also immensely influenced metabolic functions, causing long-term impact to offspring. This data indicates that more attention should be paid to the long-term health effects related to DP exposure.

To develop an appropriate sampling strategy to assess the intrauterine exposure to dechlorane plus (DP), we investigated DP levels in sequential maternal blood samples collected in three trimesters of pregnancy, respectively, from women living in Taizhou. The median concentration of DPs (sum of syn-DP and anti-DP) in all samples was 30.5 pg g−1 wet-weight and 5.01 ng g−1 lipid-adjusted weight, respectively. The trimester-related DP concentrations were consistently strongly correlated (p < 0.01), indicating that a single measurement of DP levels could represent intrauterine exposure without sampling from the same female repeatedly; however, the wet-weight levels significantly increased across trimesters (p < 0.05), while the lipid-adjusted levels did not significantly vary. Notably, whether lipid-adjusted weight or wet-weight levels, the variation extent of DP across trimesters was found to be less than 41%, and those for other persistent organic pollutants (POPs) reported in the literature were also limited to 100%. The limitation in variation extents indicated that, regardless of the time of blood collection during pregnancy and how the levels were expressed, a single measurement could be extended to screen for exposure risk if necessary. Our study provides different strategies for sampling the maternal blood to serve the requirement for assessment of in utero exposure to DP.

Dechlorane Plus (DP) is an unregulated, highly chlorinated flame retardant. It has been manufactured from past 40 years but its presence in the environment was initially reported in 2006. Later, it has been found in various biotic and abiotic environmental matrices. However, little attention has been paid to monitor its presence in Asia. Many studies have reported the occurrence of DP in the environment of Asia, yet the data are scarce, and studies are limited to few regions. The objective of present review is to summarize the occurrence, distribution, and toxicity of this ubiquitous pollutant in various environmental matrices (biotic and abiotic). DP has also been reported in the areas with no emission sources, which proves its long-range transport. Moreover, urbanization and industrialization also affect the distribution of DP, i.e., high levels of DP have been found in urban areas relative to the rural. Tidal movement also incorporates in transport of DP across the aquatic system. Further, bioaccumulation trend of DP in various tissues is kidney > liver > muscle tissues, whereas, blood brain barrier resists its accumulation in brain tissues. Additionally, gender-based accumulation trends revealed high DP levels in females in comparison to males due to strong metabolism of males. Furthermore, methodological aspects and instrumental analysis used in previous studies have also been summarized here. However, data on biomagnification in aquatic ecosystem and bioaccumulation of DP in terrestrial food web are still scarce. Toxicity behavior of syn-DP and anti-DP is still unknown which might gain the interest for future studies. [ABSTRACT FROM AUTHOR]

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Dechlorane plus (DP) is a chlorinated flame retardant with high production volume (HPV) and is widely used in our daily necessities. In the present study, a laboratory-scale microcosm was built up to simulate the uptake, depuration, bioaccumulation, and stereoselective enrichment of DP in a lower concentration and equilibration condition. Common carp (Cyprinus carpio) were used for 32 days exposure and 32 days depuration. The concentration ratios of syn-DP to total DP (fsyn values) in fish examined were lower than that in commercial products. Rate constants of uptake (kS) and elimination (ke) for the syn- and anti-DP were calculated using a first-order kinetic model. The uptake rate constants of syn- and anti-DP were 0.63 and 0.89 day−1, respectively. The depuration rate constants of syn-DP (0.11 day−1) were similar to anti-DP (0.096 day−1), suggesting that anti-DP is absorbed faster than syn-DP by common carp. The estimated bioconcentration factors for both syn-DP (5700 L/kg) and anti-DP (9300 L/kg) were higher than the bioconcentration hazard criteria outlined in the Stockholm Convention, suggesting the bioconcentration potential to aquatic organisms for DP. [ABSTRACT FROM AUTHOR]

To get an overview about distribution, levels and temporal trends of polybrominated diphenyl ethers (PBDE) and halogenated flame retardants (HFR) of emerging concern, different types of environmental samples archived in the German Environment Specimen Bank as well as fish filet samples from the Arctic (n = 13) and Antarctica (n = 5) were analysed for 43 substances (24 PBDE, 19 HFR) using a multi-column clean-up and GC-API-MS/MS or GC-MS. Sample types were herring gull egg (n = 3), blue mussel (n = 3) and eelpout filet (n = 3) from the German North- and Baltic Sea, bream filet (n = 7), zebra mussel (n = 6) and suspended particulate matter (SPM, n = 7) from German freshwater ecosystems as well as tree leaves (n = 9)/shoots (n = 10), soil (n = 4), earthworm (n = 4) and deer liver (n = 7) as representatives of German terrestrial ecosystems. PBDE and emerging HFR were present in each investigated matrices from Germany and Polar regions showing their widespread distribution. The presence in Arctic and Antarctic fish samples confirms their long-range transport potential. Average concentrations of total emerging HFR were highest in SPM (26 ng g−1 dry weight (dw)), zebra mussel (10 ng g−1 dw) and herring gull egg (2.6 ng g−1 dw). Lowest levels were measured in fish filet samples from Antarctica (0.02 ng g−1 dw). Average total PBDE concentrations were highest in bream filet (154 ng g−1), herring gull egg (61 ng g−1 dw), SPM (21 ng g−1 dw), and zebra mussel 18 (ng g−1) and lowest in deer liver (0.04 ng g−1 dw). The patterns of non-fauna terrestrial samples (leaves, shoots, soil) as well as SPM were dominated by DBDPE and BDE209. Elevated proportions of DPTE and in most cases the absence of DBDPE characterized all fauna samples with the exception of Polar samples. Overall, emerging HFR appeared to be less bioaccumulative than PBDE. Temporal trends were generally decreasing with few exceptions such as DBDPE. Image 1 • HFR were found in all investigated terrestrial, freshwater and marine matrices. • BDE 209 and DBDPE were main constituents of terrestrial and non-fauna samples. • BDE 47 and DPTE were main constituents of German freshwater and marine fauna. • Environmental concentrations were declining over time for PBDE and many emerging FR. • Emerging HFR appeared to be less bioaccumulative than PBDE. [ABSTRACT FROM AUTHOR]

Alkyl phenanthrene (A-Phen) and Dechlorane Plus (DP) are ubiquitous environmental pollutants that widely co-exist in the environment. It has been established that both A-Phen and DP elicit neurotoxicity, but the potential interactive toxicity of these contaminants is not well-known. To determine whether a mixture of A-Phen and DP would exhibit interactive effects on neurodevelopment, we co-exposed 3-methylphenanthrene (3-MP), a representative of A-Phen, with DP. Our results illustrated that exposure to 5 or 20 μg/L 3-MP alone or in combination with 60 μg/L DP caused neurobehavioral anomalies in zebrafish. In accordance with the behavioral deficits, 3-MP alone or co-exposed with DP significantly decreased axonal growth of secondary motoneurons, altered intracellular Ca2+ homeostasis and induced cell apoptosis in the muscle of zebrafish. Additionally, 3-MP alone or co-exposed with DP significantly increased reactive oxygen species (ROS) and the mRNA levels of apoptosis-related genes. These findings indicate that 3-MP alone or co-exposed with DP induces neurobehavioral deficits through the combined effects on neuronal connectivity and muscle function. Chemical analysis revealed significant increases in 3-MP and DP bioaccumulation in zebrafish co-exposed with 3-MP and DP. Elevated bioaccumulation resulting from mixture exposure may represent a significant contribution of the synergistic effects observed in combined chemical exposure. Image 1 • Neurotoxicity of 3-MP and DP co-exposure in zebrafish was firstly studied. • Co-exposure with 3-MP and DP had synergistic effects on neurobehavioral deficits. • Behavioral anomalies were due to altered neuronal connectivity and muscle function. [ABSTRACT FROM AUTHOR]

Dechlorane plus (DP) is found widely in environmental media. Determining DP concentrations in dust and hair and identifying relationships between the concentrations in dust and hair could improve our understanding of the effects of DP in humans. DP concentrations in 48 hair samples from male and female students and in 30 indoor dust samples from dormitories and classrooms used by the students were determined. The objective was to determine the difference of DP concentration between indoor dust and hair, and to explore the effect of DP in dust on DP in hair of male and female students. The mean DP concentration was significantly higher in male dormitory dust than female dormitory dust, and the estimated DP dose through exposure to dust was also significantly higher for males than females. However, the mean DP concentration was significantly higher for hair from females than from males. The median DP f anti was significantly lower for hair than dust, indicating DP may be stereoselectively metabolized by humans. The median DP f anti was significantly higher for hair from females than from males, indicating DP may be metabolized differently by males and females. Human serum albumin preferred combination with anti-DP, rather than syn-DP. DP in indoor dust was not a major direct source of the DP in the hair, meaning DP in hair mainly came from within the body. There may be significant differences in DP, particularly anti-DP, metabolism in males and females. • DP concentration in male dormitory dust was significantly higher than that in female dormitory. • DP concentration in female hair was significantly higher than that in male hair. • Anti-DP can bind HSA better than syn-DP. • DP in hair is mainly from endogenous exposure. • The significant difference in DP concentration between male and female hair was mainly caused by anti-DP. [ABSTRACT FROM AUTHOR]

Abstract Although isomer-specific bioaccumulation of dechlorane plus (DP) has been addressed in many studies, it remains unclear which factors determine this process and whether biotransformation of DP occurs in organisms. Comparative experiments were conducted in both in vivo and in ovo incubation using hens and eggs to identify the dominant factors determining the bioaccumulation of DP. Hens and fertilized eggs were exposed to DP isomers (syn - and anti -DP) by feeding and spiking, respectively, to investigate absorption, elimination, and metabolism. No significant differences were found between absorption efficiencies of DP isomers in the adult hens. Following first-order kinetics, anti -DP exhibited a slightly longer half-life than syn -DP as well as an elevated anti -DP fraction in laid eggs, thereby suggesting selective enrichment of anti -DP in adult hens. However, chicken embryos metabolized approximately 12% and 28% of the absorbed syn - and anti -DP, respectively, thereby verifying that anti -DP was preferably metabolized. This result indicated that stereo-selective excretion of syn -DP, rather than preferred metabolism of anti -DP, played a more prominent role in isomer-specific bioaccumulation of DP in chickens. Further studies on metabolites of DP are crucial to understanding the fate of DP in organisms. Graphical abstract Image 1 Highlights • Key factors determining stereo-selective bioaccumulation of DP were studied. • A selective enrichment of anti -DP was observed in hens and corresponding laid eggs. • Isomer-specific metabolism of DP was confirmed in chicken embryos. • Stereo-selective excretion of syn -DP is dominant in bioaccumulation of DP in chicken. Stereo-selective excretion of syn -DP, rather than metabolism, is the dominant factor determining bioaccumulation of DP in chicken. [ABSTRACT FROM AUTHOR]

Abstract 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. Graphical abstract Image 1 Highlights • Greenhouse can enhance the uptake of DP by vegetables. • Greenhouse vegetables have higher levels of DP than conventional vegetables. • Higher exposure risk of DP was observed via greenhouse vegetables consumption. Significant translocation was observed for compound with high K OW and concentration in greenhouse vegetables. [ABSTRACT FROM AUTHOR]

Abstract While flame retardant Dechlorane Plus (DP) and its dechlorinated analogs have been frequently detected in wildlife, knowledge is limited on their bioaccumulation and maternal transfer in amphibians. In the present study, the occurrence of syn - and anti -DP isomers and a DP dechlorinated compound, anti -Cl 11 -DP, were investigated in frogs and insects collected from the paddy field of a highly contaminated site. The concentrations of ∑DP (the sum concentrations of syn - and anti -DP) in the frog muscle, liver, and eggs were 141 ± 24.7, 454 ± 73.9, and 184 ± 31.1 ng/g lipid weight, respectively; with significantly higher levels in the males than females. The syn -, anti - and anti -Cl 11 -DP were all detectable in the frog eggs, demonstrating their maternal transfer in female frogs. The concentration ratios between eggs and liver pairs were 0.49 ± 0.01, 0.35 ± 0.01, and 0.53 ± 0.06 for syn -DP, anti -DP, and anti -Cl 11 -DP, respectively. The values of f anti (the concentration of anti -DP relative to the sum concentration of DP) differed significantly between frog tissues (0.33–0.79) and insects (0.71–0.74), indicating isomer-specific bioaccumulation of DP in the frogs. The concentration ratios of the frogs to the insects were greater than 1 for all the DP-related compounds, suggesting a possibility of biomagnification of these chemicals in the frogs. Highlights • Male frogs accumulated higher ∑DP concentrations than the females. • DP isomers were biomagnified from insects to frogs. • The f anti values in frogs were different from those in insects. • First report of the maternal transfer of DP in amphibians. [ABSTRACT FROM AUTHOR]

Abstract Biosolid application is considered a sustainable management tool as it positively contributes to recycle nutrients and to improve soil properties and fertility. Nevertheless, this waste management technique involves an important input source of emerging organic pollutants in soil. To evaluate the environmental potential risk related to perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) due to the biosolid application to soil, a quantitative ecotoxicological risk assessment was conducted. The analyte concentrations were employed to perform an estimation of the exposure levels to contaminants in the receiving media, defining predicted environmental concentrations (PECs) for terrestrial and aquatic compartments (PEC soil , PEC water , PEC sed) and for secondary poisoning via the terrestrial and aquatic food chain (PEC oral, predator (T) , PEC oral, predator (Aq)). The risk characterization ratios (RCRs) were calculated based in the comparison of the PEC values obtained with concentrations with no effect (PNECs) on terrestrial and aquatic ecosystems. Based on the chosen scenarios and experimental conditions, no environmental risk of PFASs and HFRs released from biosolid amended soils to different environmental compartments was detected (RCR soil , RCR oral, worm , RCR water , RCR sed and RCR oral, fish were below 1 in all cases). Besides, the potential health risk of PFASs and HFRs to local people who live in the scenario studied and are fed on horticultural crops grown in biosolid amended soil was also below 1, indicating that the risk is not considered significant to human health in the conditions studied. This approach provides a first insight of the risks relative to biosolid amendments to further research based on fieldwork risk assessment. Highlights • The ecotoxicological risk of PFASs and HFRs due to biosolid amendment was studied. • PECs for soil and aquatic compartments and for secondary poisoning were estimated. • RCR soil , RCR oral, worm , RCR water , RCR sed and RCR oral, fish were <1 (negligible risk). • HRs based on the consumption of tomato were <1 (negligible risk to human health). [ABSTRACT FROM AUTHOR]

Dechloranes, a type of additive polychlorinated flame retardant, which include Dechlorane (Dec) Plus (DP), Dec 602, Dec 603, and Dec 604, were detected in surficial water and sediment from the Jiulong River Estuary (JRE). The total concentration of dechloranes in the water and sediments ranged from 1.4 to 4.1 ng/L and 9.3 to 36.2 ng/g dry weight, respectively. The distribution patterns of dechloranes in the water and sediments were both dominated by DP. The average values of the anti-DP fractional abundances (fanti) in the water and sediment samples both were fell in the range of commercial DP mixtures. The relationships of DP in the water with suspended particulate matter (SPM), total organic carbon (TOC), and tides indicated that the combined actions of these environmental factors influenced the distribution of DP in the JRE. The deleterious risk associated with exposure to dechloranes via the water for adults was very low, suggesting that exposure of the local population of dechloranes via water is relatively safe in the JRE. [ABSTRACT FROM AUTHOR]

Coniferous shoots and deciduous tree leaf samples from 10 sites in Germany were taken in 2015 or 2016 within the German Environmental Specimen Bank sampling program and analysed for 24 polybrominated biphenyl ethers (PBDEs) and 19 additional halogenated flame retardants (HFRs). At one site, additional historic samples dating back till 2003 were also investigated. Samples were Soxhlet-extracted, cleaned-up by a non-destructive multi-step procedure involving gel permeation chromatography, and detected by GC-API-MS/MS as well as GC-MS. Besides PBDEs as classical HFRs, emerging HFRs such as Dechlorane Plus, DPTE, DBDPE, or ATE were region-wide observed demonstrating their widespread occurrence in the atmosphere. Highest concentrations in recent samples were found for DBDPE (<230–2760 pg g −1 dry weight (dw)) followed by DPTE (91–1540 pg g −1 dw), BDE209 (<156–461 pg g −1 dw), and BDE47 (<27–505 pg g −1 dw) or DP (31–122 pg g −1 dw). The overall uniform and widespread distribution as well as similar HFR levels and composition profiles observed in recent conifer shoots and corresponding deciduous tree leaves from the same area indicate a prolonged medium to long-range transport as sources. Furthermore, it is demonstrated that both tree types are generally suitable bioindicators for atmospheric pollution with HFRs, although accumulation may vary depending on HFR properties and accumulation period. The historic samples showed decreasing PBDE levels whereas no clear trend could be observed for other investigated HFRs at this site. [ABSTRACT FROM AUTHOR]

We investigated the occurrence of halogenated flame retardants (HFRs) including polybrominated diphenyl ethers (PBDEs), six novel brominated flame retardants (NBFRs) and dechlorane plus in air and soils on the eastern slope of Mt. Gongga on the eastern Tibetan Plateau. We detected all of the NBFR except bis(2-ethylhexyl)-tetrabromophthalate and pentabromoethyl benzene. NBFRs constituted the most prevalent group. BDE-28 and BDE-47 dominated among the PBDE congeners. Decabromodiphenyl ethane was detected at relatively high levels up to 171 pg/m3 and 1450 pg/g dry weight in air and soils, respectively; however, it appeared to be easily degraded in the environment. A general decreasing trend was observed among the HFR concentrations with increasing altitude, and this was due to the prominent contribution of source emissions over possible influence of environmental conditions. This study also suggests that HFRs are supplied to forest soils mainly in the form of precipitation and retained in the O horizon layers. [ABSTRACT FROM AUTHOR]

Dechlorane Plus (DP), a chlorinated flame retardant, is increasingly reported in aquatic ecosystems worldwide. But little information is available regarding the toxicity of DP in marine organisms, especially in macroalgae. The objective of this study was to investigate effects of DP exposure on photosynthesis, oxidative stress and its enrichment in juvenile marine macroalgae ( Ulva pertusa ). Following 21- day uptake and 21- day depuration (10 −8  mol/L), algae accumulated 1.18 times of DP compared to the initial concentration. Anti-DP was prone to accumulate in juvenile macroalgae. The enrichment of DP affected the physiological responses in algae. After 1, 7 and 14 days DP exposure (10 −8 , 10 −7 and 10 −6  mol/L), antioxidant enzymes (SOD and CAT) activities and MDA content changed in a dose and time depended manner. Chlorophyll fluorescence parameters, including F v /F m , Φ PSII and ETR decreased with the increasing DP concentration. It indicated that DP leads to a low rate of light energy utilization in algae which may ascribe to the oxidative damage induced by DP enrichment. Present study provides insight into the toxicological effects of DP on marine macroalgae, which is useful for risk assessment of DP in intertidal zone ecosystems. [ABSTRACT FROM AUTHOR]

In this study, polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and dechlorane plus (DPs) were analyzed in seven categories of building and decoration materials. The total concentrations of analyzed FRs ranged from 1.19 ng/g (diatomite powder) to 9532 ng/g (expanded polystyrene panel). Relatively high concentrations were detected in foam samples and PVC materials, followed by sealing materials, boards, wallpaper, paints, and wall decoration powders. BDE209 was the most detected compound with the highest concentrations in almost all materials, followed by decabromodiphenyl ethane (DBDPE), which was consistent with their productions and consumptions in China. The estimated PBDE concentrations in air and dust based on material concentration and emission rate were comparable with those detected in real samples. Adult and infant exposures via inhalation and dust ingestion were assessed. The estimated exposures to BDE209 via dust ingestion were 1.36 and 0.12 ng/(kg bw d), which were 19- and 4-fold higher than those via inhalation for infants and adults, respectively. This suggested that dust ingestion was a significant pathway of human BDE209 exposure, especially for infants. For the other PBDE congeners (∑ 7 PBDEs), the estimated exposures via inhalation were 2.60 and 1.32 ng/(kg bw d) for infants and adults, respectively. Despite the low estimated human exposures to PBDEs compared to the oral reference doses, the exposure associated with building and decoration materials still requires more attention because of the potential risks from other exposure pathways and undetected FRs in those materials. [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs, tri-to hepta-BDEs) and Dechlorane Plus (DP) in multiple samples (soil, sediment, road dust, and PM 2.5 particles) in historical locations of our previous work in Guiyu (electronic-waste recycling town) in southeastern China were investigated in 2014. Ten years later, PBDEs and DP were detected in 100% of the samples. Ʃ 3-7 PBDEs were still relatively great, ranging from 1.2 × 10 1 to 2.1 × 10 3  ng/g dry weight (dw) in soil, 2.1 to 3.2 × 10 3  ng/g dw in sediment, 1.0 × 10 1 to 1.1 × 10 4  ng/g dw in road dust, which were a little less than or close to those measured in 2004. However, Ʃ 3-7 PBDEs in PM 2.5 (5.0 × 10 2 to 8.4 × 10 2  pg/m 3 ) were significantly lower in 2014. BDE-47, -99, −153, and −183 were predominant congeners, which were also predominant PBDEs reported in Guiyu (2006–2008). Greater proportions of lesser-brominated BDEs were predominant in PM 2.5 than other samples. DP was detected in 100% of the samples collected with high levels. Total syn-DP and anti-DP concentrations were 3.8 to 2.1 × 10 3  ng/g dw in soil, 1.1 × 10 3 to 7.2 × 10 3  ng/g dw in sediment, 1.4 × 10 1 to 1.1 × 10 3  ng/g dw in road dust, and 1.8 × 10 2 and 1.7 × 10 2  pg/m 3 in PM 2.5 . Most of the fractions of anti-DP ( f anti ) (70%–80%) were consistent among samples. The health risk assessment showed that hazard indexes (HIs) of PBDEs or DPs for child or adult were all lower than 0.16. [ABSTRACT FROM AUTHOR]

Dechlorane Plus (DP) is a chemical of emerging concern due to the restrictions on brominated flame retardant formulations. However, very little information is known about the occurrence of DP in indoor and outdoor air and its associated health risk to the exposed human population. In this study, we examined the concentrations and isomer profiles of DP in archived air samples collected from 14 homes, 6 offices, and 10 public microenvironments in Guangzhou, China in 2004-2005. The average (median) value of atmospheric ΣDP (sum of anti-DP and syn-DP) concentration in the three indoor air was 5.73 ± 5.33 (3.62) for offices, 8.08 ± 5.17 (6.87) for homes, and 57.27 ± 83.08 (32.58) pg/m3 for public microenvironments, respectively. ΣDP concentration was significantly higher in the public microenvironments than those in homes and offices. The arithmetic mean and median concentrations of ΣDP in outdoor air were 36.00 and 28.76 pg/m3, respectively. Spatially and temporally consistent indoor and outdoor samples comparison suggested that outdoor air might be a relevant source of DP for indoor air. Average anti-DP fractional abundance (fanti = 0.65 ± 0.04) in all outdoor samples was similar to those reported in other studies and indistinguishable from that of the commercial mixture (fanti = 0.65). In contrast, a relatively large variation of fanti values was found in the indoor samples, suggesting a complex degradation process of DP existing in these microenvironments. The calculated average daily doses of ΣDP were in the range of 0.38-2.21 ng/day for people intake through air inhalation, which was in the same order of magnitude compared with other exposure pathways for the general publics. [ABSTRACT FROM AUTHOR]

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and Dechlorane Plus (DP) are two chlorinated, alternative flame retardants that have been found in wild birds and bird eggs. Little is known about the fate and effect of these compounds in birds, especially during the vulnerable stages of embryonic development. To investigate the ability of birds to biotransform these compounds, an in ovo exposure experiment with Japanese quail eggs was performed. Quail eggs were injected in the yolk sac with 1000 ng/g egg of TDCIPP (2.3 nmol/g ww), DP (1.5 nmol/g ww) or a mixture of both and were then incubated at 37.5 °C for 17 days. To get a time-integrated understanding of the in ovo transformation of the compounds, one egg per treatment was removed from the incubator every day and analyzed for TDCIPP and its metabolite bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and/or for DP. By the end of the incubation period, TDCIPP was completely metabolized, while simultaneously BDCIPP was formed. The conversion of the parent compound into the metabolite did not occur proportionally and the concentration of BDCIPP showed a tendency to decrease when TDCIPP became depleted, both indicating that BDCIPP was further transformed into compounds not targeted for analysis. Further untargeted investigations did not show the presence of other metabolites, possibly due to the volatility of the metabolites. On the other hand, the DP concentration did not decrease during egg incubation. This study indicates that within the incubation period, avian embryos are able to biotransform TDCIPP, but not DP. [ABSTRACT FROM AUTHOR]

The extensive application of halogenated flame retardants has led to their widespread distribution in the environment. Recently, concerns emerged regarding their potential persistence, (bio)accumulation, and/or toxicity. Particularly halogenated flame retardants based on norbornene structures, like Dechlorane Plus as well as other brominated PBDE replacements, generically called emerging, novel, or alternative flame retardants, are in the focus of interest. A comprehensive analytical method for the determination of 21 halogenated flame retardants (HFRs) of different substance classes (dechloranes, brominated aromates, brominated ethers, cyclic BFR) in a broad variety of matrices (tree leaves, fish fillet, birds eggs, suspended particles) was developed in order to assess their environmental levels as well as temporal trends, especially for the use within environmental specimen banks (ESBs). In addition to the alternative HFRs, a set of 24 PBDEs were measured in the same samples, however using GC-EI-MS for detection. Samples were extracted using accelerated solvent extraction (ASE) with dichloromethane:hexane (exception: soxhlet extraction for suspended particles) followed by a multi column clean-up. Quantification was performed by API-GC-MS/MS as a modern, gentle, and sensitive technique for simultaneous detection of compounds throughout a wide range of masses and fragmentation characteristics (exception: PBDE detection using GC-EI-MS). With the exception of BDE 209, instrumental precisions of target compounds ranged from 1% to 16 % (at levels of 2 pg injection for HFR, 20 pg injection for DBDPE, 7-36 pg injection for PBDEs). Interday precisions of the entire analytical method including extraction and clean-up were mostly below 25% for all validation matrices at spiked levels of 100 pg sample for HFR (DBDPE: 1000 pg sample) and 1200-6000 pg sample for PBDEs. The majority of analytes were investigated with expanded measurement uncertainties of less than 50%. [ABSTRACT FROM AUTHOR]

An analytical method has been developed for the trace determination of 10 dechlorane-related compounds (DRCs) in food products by gas chromatography – high resolution mass spectrometry (GC-HRMS). The highest sensitivity of this instrumental analysis method was achieved by selection of the GC column type, optimization of the heated zones within the instrument, and adjusting the electron impact energy. The efficiency of solid phase extraction as clean-up procedure was also optimized. Two different types of cartridges - neutral silica gel and Florisil ® , as well as seven organic solvents or their mixtures - n -hexane, cyclohexane, acetone, toluene, n -hexane/ethyl acetate, n -hexane/acetone, and n -hexane/dichloromethane - were evaluated. The analytical method was characterized as selective, precise, accurate, and linear over the concentration ranges from 1.00 to 100 pg μL −1 for DRCs. Ultra-trace level sensitivity was achieved with the instrumental limits of quantification (i-LOQs) varying from ∼0.01 pg to ∼ 1 pg and method limits of quantification ( m -LOQs) by the analysis of 10 g of sample varying from ∼0.04 to ∼ 5 pg g −1 . The developed method was successfully applied for the analysis of food samples and the analyses revealed the presence of majority of selected DRCs, with the Dechlorane Plus (DP) isomers occurring to a greater extent, pointing to the highest levels in cod liver and other fish products. [ABSTRACT FROM AUTHOR]

Brominated flame retardants (BFRs) and Dechlorane Plus (DP) were measured in both human hair and paired serum samples from a cohort of university students in South China. Segmental analysis was conducted to explore gender difference and the relationships between the hair and serum. The concentrations of total PBDEs in the hair and serum samples were in a range of 0.28–34.1 ng/g dry weight (dw) and 0.16–156 ng/g lipid weight (lw), respectively. Concentrations of ∑DPs (sum of the syn -DP and anti -DP isomers) in all hair samples ranged from nd-5.45 ng/g dry weight. Concentrations of most PBDEs and decabromodiphenylethane (DBDPE) in distal segments (5–10 cm from the scalp) were higher than those in the proximal segments (0–5 cm from the scalp) ( t -test, p < 0.05), which could be due to the longer exposure time of distal segments. The proximal segments exhibited a unique congener profile, more close to that in the serum rather than the distal segments of hair. An obvious gender difference was found in the levels of ∑PBDEs using integrated hair samples, while the difference disappeared when considering alone the proximal segments of hair (0–5 cm from scalp) for both genders. This paper provides supplement to the current knowledge on sources of BFRs and DPs in hair and declares the importance of segmental analysis. [ABSTRACT FROM AUTHOR]

As an emerging halogenated organic contaminant, Dechlorane Plus (DP) was scarcely reported in marine environments, especially in China. In this work, 35 surface sediments and a sediment core were collected across the Southern Yellow Sea (SYS) to comprehensively explore the spatio-temporal distribution and possible migration pathway of DP. DP concentrations ranged from 14.3 to 245.5 pg/g dry weight in the surface sediments, displaying a seaward increasing trend with the high levels in the central mud zone. This spatial distribution pattern was ascribed to that fine particles with the elevated DP levels were preferentially transported to the central mud zone under hydrodynamic forcing and/or via long-range atmospheric transportation and deposition. DP concentrations in sediment core gradually increased from the mid-1950s to present, which corresponded well with the historical production and usage of DP, as well as the economic development in China. Significantly positive correlation between DP and total organic carbon (TOC) in both surface sediments and sediment core indicated TOC-dependent natural deposition of DP in the SYS. We used multiple biomarkers, for the first time, to explore the potential effects of terrestrial and marine organic matters (TOM and MOM) on DP deposition. The results showed that competition may occur between TOM and MOM for DP adsorption, and MOM was the predominant contributor in controlling DP deposition in the marine sediments from the SYS. [ABSTRACT FROM AUTHOR]

Concentrations and spatial distribution pattern of organohalogen flame retardants were investigated in the riverine surface sediments from Taizhou, an intensive e-waste recycling region in China. The analytes were syn - and anti - Dechlorane Plus (DP), Dechloranes 602, 603, and 604, a DP monoadduct, two dechlorinated DPs and 8 congeners of polybrominated diphenyl ethers (PBDEs). The concentrations of Σ 8 PBDEs, ΣDP, ΣDec600s, and ΣDP-degradates ranged from <100 to 172,000, 100 to 55,000, not detectable (nd) to 1600, and nd to 2800 pg/g dry weight, respectively. BDE-209 and DP, both have been manufactured in China, had similar spatial distribution patterns in the study area, featured by distinctly recognizable hotspots some of which are in proximity to known e-waste dumping or metal recycling facilities. Such patterns were largely shared by Dec602 and dechlorinated DP, although their concentration levels were much lower. These major flame retardants significantly correlate with each other, and cluster together in the loading plot of principle component analysis. In contrast, most non-deca PBDE congeners do not correlate with DPs. Dec604 stood out having distinctly different spatial distribution pattern, which could be linked to historical use of mirex. Organic matter content of the sediment was not the dominant factor in determining the spatial pattern of pollution by halogenated flame retardants in the rivers of this study. [ABSTRACT FROM AUTHOR]

Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2′,4,4′,5,5’-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo- p -dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13–1014 ng g −1 . The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048–3.3 ng g −1 , while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8–153 ng g −1 and 0.43–15 ng g −1 , respectively. DP was another primary FR, with concentrations of 0.57–146 ng g −1 . Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5–17 pg TEQ g −1 . 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants. [ABSTRACT FROM AUTHOR]

During an investigation of the potential associated with coupling packed column supercritical fluid chromatography (pSFC) to mass spectrometry for the analysis of Dechlorane Plus and related compounds, it was found that negative ion atmospheric pressure chemical ionization (APCI) was a promising ionization technique. In the course of maximizing the responses associated with the target analytes, it proved useful to examine some aspects of the complex nature and reactivity of the corona discharge plasma generated to explain the observed ionization products. Various dopants/reagents were screened for both APCI and atmospheric pressure photoionization (APPI) in negative ion mode and mechanisms of ionization involving superoxide were elucidated based on the results obtained. Superoxide formation was found to be temperature dependent and directly related to the intensity of the ion cluster [M-Cl+O] - obtained for the target DP analytes. Furthermore, triethylamine was identified as a reagent capable of suppressing unwanted side reactions during the ionization process and maximizing response associated with the analytes of interest. The applicability of pSFC-APCI/MS for the separation and detection of Dechlorane Plus and related compounds was demonstrated by analyzing Lake Ontario sediment and comparing the results with values reported in the scientific literature. [ABSTRACT FROM AUTHOR]