Dechlorane-related Compounds Research Articles

Spatial distribution of Dechlorane Plus and dechlorane related compounds in European background air

The highly chlorinated chemical Dechlorane Plus (DP) was introduced as a replacement flame retardant for Mirex, which is banned through the Stockholm Convention (SC) for its toxicity (T), environmental persistence (P), potential for bioaccumulation (B) and long-range environmental transport potential (LRETP). Currently, Dechlorane Plus is under consideration for listing under the Stockholm Convention and by the European Chemical Agency as it is suspected to also have potential for P, B, T and LRET. Knowledge of atmospheric concentrations of chemicals in background regions is vital to understand their persistence and long-range atmospheric transport but such knowledge is still limited for Dechlorane Plus. Also, knowledge on environmental occurrence of the less described Dechlorane Related Compounds (DRCs), with similar properties and uses as Dechlorane Plus, is limited. Hence, the main objective of this study was to carry out a spatial mapping of atmospheric concentrations of Dechlorane Plus and Dechlorane Related Compounds at background sites in Europe. Polyurethane foam passive air samplers were deployed at 99 sites across 33 European countries for 3 months in summer 2016 and analyzed for dechloranes. The study showed that syn- and anti-DP are present across the European continent (<MDL-2.6 pg/m3 and <MDL-12.3 pg/m3, respectively), including parts of the Arctic. This supports that these compounds have potential for long-range atmospheric transport to remote regions. The highest concentrations of Dechlorane Plus were observed in central continental Europe, with anti-DP fractions close to the commercial mixture of Dechlorane Plus. The only detected Dechlorane Related Compounds was Dechlorane-602, which was found in 27% of the samples (<MDL-0.33 pg/m3). The measured concentrations and spatial patterns of Dechlorane Plus and Dechlorane-602 in air across Europe indicate the influence of primary sources of these compounds on background concentrations in European air. Future air monitoring efforts targeting dechloranes is needed in both background and source areas, including consistent temporal trends.

Simultaneous determination of hexabromocyclododecanes, polybrominated diphenyl ethers, and dechlorane-related compounds in boxed sushi meals using a developed analytical method

We investigated the concentrations of halogenated flame retardants (HFRs), which include hexabromocyclododecanes (HBCDDs), polybrominated diphenyl ethers (PBDEs), and dechloranes and related compounds (DRCs), in 25 typical ready-made boxed sushi meals (each divided into seafood and non-seafood portions) using a developed simultaneous analytical method involving accelerated solvent extraction and gel permeation chromatographic separation. The developed method yielded good recoveries of surrogates (72–122 %). HBCDDs, PBDEs, and DRCs were detected in all seafood portions. While DRCs were also frequently detected in non-seafood portions, HBCDDs and PBDEs were hardly detected. The estimated dietary intakes of HBCDDs, PBDEs, and DRCs from boxed sushi meals were well below the corresponding health-based guideline values. In conclusion, our study suggests that the intake of HFRs from boxed sushi meals poses low concern for consumer health and that the developed simultaneous analytical method is highly useful for determining HFRs in seafood-based meals.

Simultaneous Determination of Hexabromocyclododecanes, Polybrominated Diphenyl Ethers, and Dechlorane-Related Compounds in Boxed Sushi Meals Using a Newly Developed Analytical Method

Simultaneous Determination of Hexabromocyclododecanes, Polybrominated Diphenyl Ethers, and Dechlorane-Related Compounds in Boxed Sushi Meals Using a Newly Developed Analytical Method

Legacy and alternative brominated, chlorinated, and organophosphorus flame retardants in indoor dust—levels, composition profiles, and human exposure in Latvia

Flame retardants (FRs) are additives used in consumer products to reduce flammability, even though they can easily contaminate the indoor environment. Since it is common for people in modern cities to spend up to 85% of time indoors, the quality of the indoor environment is critical for human health. In this study, polybrominated diphenyl ethers (PBDEs), organophosphorus flame retardants (OPFRs), emerging brominated flame retardants (EBFRs), and dechlorane-related compounds (DRCs) were measured in household dust samples (n=34) from Latvia, followed by human exposure assessment. Among all studied compounds, OPFRs showed the highest concentrations (1380-133,000ngg-1). Despite the phase-out of PBDEs, they were the second most significant flame retardants in the studied dust samples (468-25,500ngg-1) and the predominant compound was BDE-209. The concentrations of EBFRs were in the range of 120-7295ngg-1, with the most abundant contaminant being DBDPE, which is widely used as a substitute for the deca-BDE formulation. DRCs were the least common flame retardants in the Latvian indoor environments, with concentrations ranging 22.4-192ngg-1. Although the concentrations of specific FRs are known to vary between different countries, the levels and patterns observed in dust samples from Latvia were similar to those reported from Central Europe. Human exposure was evaluated as the estimated daily intake (EDI). The calculated exposure to most of the FRs was several orders of magnitude lower than the available reference dose (RfD) values.

Dechlorane Plus and Related Compounds in Food-A Review.

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

Polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDD), dechlorane-related compounds (DRCs), and emerging brominated flame retardants (EBFRs) in foods: The levels, profiles, and dietary intake in Latvia

This study was performed to assess the Latvian population exposure to polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDD), dechlorane-related compounds (DRCs), and emerging brominated flame retardants (EBFRs). Food items including fish, fish products, meat, dairy products, cereals and bread, eggs, vegetable oils, and sweets were analyzed for the content of these contaminants, followed by per capita intake calculations and risk assessment. The highest dietary exposure for general population was observed in the case of HBCDD, .reaching an estimated daily intake (EDI) value of 2.92 ng kg−1 b.w. (or 3.35 ng kg−1 b.w. if an outlying data point is included), followed by PBDEs with EDI of 1.24 ng kg−1 b.w., including ~25% contribution of PBDE-209 to the overall EDI from PBDEs. DRCs and EBFRs were secondary contributors to the total intake of selected flame retardants (FRs), with the observed EDIs of 0.46 and 0.47 ng kg−1 b.w, respectively. The obtained occurrence data and risk characterization according to the European Food Safety Authority (EFSA) approach showed the calculated margin of exposure (MOE) values higher than the critical values for PBDE-47, −99 and -153as well as for HBCDD, indicating that the estimated dietary exposures are unlikely to be of significant health concern for the Latvian population. At the same time, it should be pointed out that the risk assessment was performed only for five out of the twenty-five selected halogenated flame retardants (HFRs), while cumulative effects due to the potential presence of other HFRs and their biodegradation products were not considered.

Halogenated organic contaminants of concern in urban-influenced waters of Lake Ontario, Canada: Passive sampling with targeted and non-targeted screening

Passive samplers are useful tools for monitoring hydrophobic, persistent, and potentially bioaccumulative contaminants in the environment. In this study, low density polyethylene passive samplers were deployed in urban-influenced and background nearshore freshwaters of northwestern Lake Ontario and analyzed for a broad range of both legacy halogenated organic contaminants (HOCs) and halogenated flame retardants (HFRs). Non-targeted analysis was conducted for screening additional halogenated substances. For most compounds, concentrations were greatest in the industrialized Hamilton Harbour and more generally at sites that have stronger influences of wastewater effluent discharges and stormwater run-off through rivers and creeks. Polychlorinated biphenyls (PCBs) remain the dominant class of HOCs in water, with dissolved-phase concentrations ranging from 10 to 4100 pg/L (ΣPCBs), followed by polybrominated diphenylethers (ΣPBDEs; 14–960 pg/L) and the organochlorine pesticides (OCPs; 22–290 pg/L). Several non-PBDE brominated flame retardants (nBFRs) and chlorinated Dechlorane-related compounds were detected, with hexabromocyclododecanes (ΣHBCDD; sum of 3 diastereoisomers) the most abundant (1.0–21 pg/L). Non-targeted screening of samples by high resolution mass spectrometry using Kendrick mass defect plots for data analysis indicated that several other halogenated compounds were present in waters at relatively high abundances compared to the flame retardants, based on semi-quantitative estimates. These included methyl-triclosan, four halogenated anisoles (2,4,6-tribromoanisole, dimethyl-trichloroanisole, pentachloroanisole, and pentachlorothioanisole), and pentachloro-aniline. Dissolved-phase methyl-triclosan was estimated to contribute up to approximately 40% of the summed target HOC concentrations. Polyethylene passive samplers provided an excellent medium for both non-targeted screening of HOCs not currently included in monitoring programs and tracking brominated and chlorinated chemicals slated for reductions in uses and emissions through international (Stockholm Convention) and binational (Great Lakes) agreements.

Changes in plasma biochemistry in breeding ring-billed gulls: Effects of anthropogenic habitat use and contaminant exposure

Gulls (Larids) have become successful at exploiting anthropogenic areas for foraging. However, little is known on the health implications of using anthropogenic habitats and on the associated exposure to environmental contaminants, particularly with respect to plasma biochemistry that is routinely used to diagnose physiological disorders and diseases. The objective of the present study was to investigate the effects of anthropogenic habitat use and exposure to ubiquitous halogenated flame retardants (HFRs) on plasma biochemistry of urban-breeding ring-billed gulls (Larus delawarensis) from one of the largest colonies in North America. Miniature GPS dataloggers were used to characterize foraging habitat use of individual gulls (n = 39) at the regional scale (urban, waste management facilities, agricultural fields, and St. Lawrence River) in the Montreal area (QC, Canada), and plasma was analyzed for a suite of biochemical measures (waste products, lipids, glucose, ions, proteins, and enzymes) and HFRs. Several confounding biological and environmental variables were also assessed including sex, body condition, time spent fasting while incubating, plasma thyroid hormone levels, time of day, capture date, and ambient temperature. As ring-billed gulls (males and females combined) spent more time foraging in urban areas, their plasma concentrations of cholesterol, albumin and activity of alkaline phosphatase increased significantly. Moreover, as the gulls spent more time foraging in agricultural fields, their plasma concentrations of phosphorous and activity of aspartate aminotransferase increased significantly. Only the activity of aspartate aminotransferase was significantly positively related to plasma HFR concentrations (PBDEs and dechlorane-related compounds). Time spent fasting while incubating, plasma thyroid hormone levels, body condition, time of day, and capture date were significantly related to certain plasma biochemical measures. The present results suggest that both the use of anthropogenic habitats for foraging and exposure to HFRs may affect the plasma biochemistry of ring-billed gulls breeding in the densely-populated Montreal area, suggesting potential adverse health effects for avian wildlife living in highly urbanized environments.

Novel and legacy per- and polyfluoroalkyl substances in bald eagle eggs from the Great Lakes region

Decades of large-scale production of per- and polyfluoroalkyl substances (PFASs) have resulted in their ubiquitous presence in the environment worldwide. Similarly to other persistent and bioaccumulative organic contaminants, some PFASs, particularly the long-chain congeners, can be biomagnified via food webs, making top predators vulnerable to elevated PFAS exposure. In this study, we measured seven classes of PFASs in bald eagle (Haliaeetus leucocephalus) eggs for the first time. The eggs (n = 22) were collected from the North American Great Lakes in 2000–2012. The ranges of total concentrations of perfluoroalkyl sulfonic acids (∑PFSAs) and perfluoroalkyl carboxylic acids (∑PFCAs) were 30.5–1650 and 5.4–216 ng/g wet weight (ww), respectively. In addition to these traditional PFAS compounds, 6:2 fluorotelomer sulfonic acid (6:2 FTS; median: 15.7 ng/g ww), perfluoro-4-ethylcyclohexanesulfonic acid (PFECHS; 0.22 ng/g ww), and 8-chloro-perfluorooctanesulfonic acid (Cl-PFOS, detected in wildlife for the first time; 0.53 ng/g ww) were also frequently detected. Bald eagle eggs from breeding areas located less than 8 km from a Great Lake shoreline or tributary had significantly greater total PFAS concentrations (∑PFASs) than those from breeding areas located further than 8 km (p < 0.05). In these samples, ∑PFASs rivalled the total concentration of brominated flame retardants, and were significantly greater than those of several other organic contaminants, such as dechlorane-related compounds, organophosphate esters, and flame retardant metabolites.

Assessment of Dechlorane Plus and related compounds in foodstuffs and estimates of daily intake from Lebanese population

Dechlorane Related Compounds (DRCs), including Dechlorane Plus (syn/anti-DP or syn/anti-DDC-CO) and related compounds (Dec-601 or DDC-ID, Dec-602 or DDC-DBF, Dec-603 or DDC-Ant and Chlordene Plus or DDC-PDD), are a group of polychlorinated flame retardants of concern since they were first reported in various environmental and biota matrices about one decade ago. In this work, we investigated the dietary intake of the Lebanese population to these lipophilic environmental contaminants upon the evaluation of selected foodstuff contamination. Collected food samples (n = 58) were selected to be representative of the lipid fraction of the whole diet of the Beiruti population. The samples were analysed using pressurized liquid extraction, silica multilayer column followed by gel permeation chromatography for purification and GC-EI-HRMS for separation and detection. Detection frequency of at least one compound among Dechlorane Plus (syn-DP and anti-DP), Dechlorane 602, 603 and Chlordene Plus) was 91%. The mean concentrations of ∑6DRCs, by food group, ranged from 4.7 to 29.5 pg g−1 wet weight in lowerbound (LB) and from 6.7 to 76.9 pg g−1 wet weight in upperbound (UB). Based on food habits, the dietary intake of Beiruti adults was estimated to be between 3.71 (LB) and 5.61 (UB) ng day−1. Dechlorane Plus and Dechlorane 602 were the dominant compounds, contributing to 70 and 24% of the total intake (LB value), respectively. This study reports for the first time the occurrence of Dechloranes in Lebanese foods and proposes corresponding deterministic dietary exposure scenario.

Occurrence of legacy and emerging organic pollutants in whitemouth croakers from Southeastern Brazil

The whitemouth croaker (Micropogonias furnieri) is one of the most commercially important species along the Atlantic coast of South America. Moreover, some of its biological traits (long life span, inshore feeding, high trophic position) make this species a suitable sentinel of coastal pollution. Here, we investigated contamination by multiple legacy and emerging organic pollutants, such as brominated and chlorinated flame retardants, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in whitemouth croakers from two estuaries (Guanabara and Sepetiba Bays) located in industrialized and urbanized areas in Rio de Janeiro State, Southeastern Brazil. Furthermore, we assessed how biological and ecological features could explain the observed contamination patterns. Regarding brominated flame retardants, concentrations of polybrominated diphenyl ethers (PBDEs) varied from 7.6 to 879.7 pg g−1 wet weight (w.w.), with high contribution of tetra-, penta-, hexa- and deca-BDEs. The sum of chlorinated flame retardants (dechlorane-related compounds, ΣDRC) ranged from <LOD to 41.1 pg g−1 w.w., mostly represented by Dechlorane 603 and Dechlorane Plus (DP). Concentrations of PCDDs and PCDFs varied from <LOD to 1.7 pg g−1 w.w., while the Toxic Equivalent (TEQ-PCDD/Fs) levels ranged from 0.1 to 0.2 pg g−1 w.w. Positive correlations between δ15N and concentrations of tri-, tetra- and penta-BDEs, as well as ΣDRC, DP and anti-DP isomers suggested that ecological factors (namely biomagnification along the food web) influence contamination of whitemouth croakers in the estuaries studied. Moreover, the sum of PBDEs (ΣPBDE), tri- and tetra-BDEs concentrations were negatively correlated with fish size, suggesting that depuration by fishes and/or habitat shift throughout the whitemouth croaker's life cycle might also influence concentrations. Overall, our study emphasized the need for further investigations to help understand the complex patterns of bioaccumulation and biomagnification that seem to exist in Southeastern Brazil.

Multi-analyte method for the analysis of legacy and alternative brominated and chlorinated flame retardants in food products of animal origin using gas chromatography - magnetic sector high resolution mass spectrometry

An analytical method was developed and validated for the analysis of 32 halogenated flame retardants (HFRs), including 13 polybrominated diphenyl ethers (PBDEs), 9 dechlorane-related compounds (DRCs) and 10 of the so-called alternative BFRs in food samples of animal origin. Gas chromatography (GC) coupled with magnetic sector high resolution mass spectrometry (HRMS) was used for the instrumental analysis. Intralaboratory validation of the developed method was performed in terms of recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ). Where possible, trueness was verified by the analysis of reference materials (RMs). For analytes with available isotopically labeled surrogates, recoveries in the range of 70–120% and repeatability rates below 20% were observed, while for compounds quantitated using absolute calibration the values of recovery ranged from 59 to 153% and the repeatability in terms of RSDs was in the range of 1–26%. The values measured for the four analyzed RMs agreed with the provided consensus values, revealing that the recovery of reference concentrations for compounds with assigned consensus values was in 72–119% range. The elaborated method met the sensitivity criteria according to the Commission Recommendation, 2014/118/EU on the monitoring of BFRs in food products. The developed method was successfully applied for the analysis of numerous food samples. The analyses revealed ubiquitous presence of PBDEs and the majority of DRCs in the analyzed samples, while alternative BFRs were detected only occasionally.

Is the urban-adapted ring-billed gull a biovector for flame retardants?

Birds may act as biovectors of nutrients and contaminants at the regional scale and potentially increase the exposure to such substances in ecosystems frequented by these birds. However, no study has estimated biotransport of contaminants by individual birds through their feces (guano). Elevated concentrations of halogenated flame retardants (HFRs) have been reported in ring-billed gulls (Larus delawarensis) breeding near Montreal (QC, Canada)- a known hotspot for HFRs. The objective of the present study was to investigate the concentrations of polybrominated diphenyl ethers (PBDEs) and selected emerging HFRs (e.g., Dechlorane-related compounds) in guano of individual ring-billed gulls, and to assess the relative accumulation of these HFRs by comparing concentrations in plasma (absorbed) versus guano (excreted). A second objective was to determine the importance of one of the largest ring-billed gull colony (Deslauriers Island) in North America located near Montreal as a vector of HFR biotransport at the regional scale. Elevated concentrations of PBDEs and Dechlorane plus were determined in guano and plasma of ring-billed gulls, although in general no difference was found between males and females. However, plasma to guano concentration ratios were significantly greater in females for the highly hydrophobic BDE-209 and Dechlorane plus compared to males. Overall, for both sexes combined, the total amount of HFRs (sum of the 16 major PBDEs and five emerging HFRs) deposited by this entire colony (64,980 gulls) in the Montreal area through guano during the 28-days incubation period was estimated to 1 g. This study showed that urban-adapted ring-billed gulls from this large colony represent an underestimated biovector of HFRs, which may contribute to augment exposure to these toxic compounds in nearby ecosystems.

Occurrence of Dechlorane Plus and related compounds in catfish (Silurus spp.) from rivers in France

Dechlorane related compounds (DRCs), including Dechlorane Plus (syn-DP and anti-DP), Dechlorane-601, -602, -603 and Chlordene Plus (CP), constitute a group of polychlorinated flame retardants (FRs) that are still of industrial use. In particular, DRCs have been detected in various environmental matrices and in different aquatic and terrestrial biota, thus exhibiting bioaccumulation and biomagnification potentials. The present study aimed at producing first occurrence data of a range of DRCs in Silurus spp. samples from different rivers located in France. Determination was carried out by gas chromatography high-resolution mass spectrometry after a sample clean-up based on a multilayer silica column and gel permeation chromatography. The concentration of monitored ΣDRCs ranged from 1.58 to 408 pg g−1 wet weight (54–11100 pg g−1 lipid weight). The fractional abundance of syn- and anti-DP stereoisomers was similar to that reported by other studies with an average equal to 0.60. Dec-601 was not detected in any sample. Detection frequencies ranged between 34 and 100% for other DRCs. Investigated correlations between DRCs and polychlorobiphenyls (PCBs) suggest a link with lipid content but independent contamination sources.

Accumulation of flame retardants in paired eggs and plasma of bald eagles

In this study, we measured the concentrations of 58 flame retardants (and related compounds) in bald eagle (Haliaeetus leucocephalus) egg and plasma samples from the Michigan. These analytes include polybrominated diphenyl ethers (PBDEs), novel flame retardants (nFRs), Dechlorane-related compounds (Decs), and organophosphate esters (OPEs). A total of 24 paired eaglet plasma and egg samples were collected from inland (IN, N = 13) and the Great Lakes (GL, N = 11) breeding areas from 2000 to 2012. PBDEs were the most abundant chemical group with a geometric mean of 181 ng/g wet weight (ww) in egg and 5.31 ng/g ww in plasma. Decs were barely found in plasma samples, but they were frequently found in eggs (geometric mean 23.5 ng/g ww). OPE levels were comparable to those of PBDEs in the plasma but lower than those of PBDEs in eggs. Dec and PBDE concentrations were significantly higher in GL than in IN (p < 0.05). The ratio of egg to plasma concentrations (lipid normalized) varied with chemicals and correlated with the chemical's octanol-water partition coefficient. The lipid normalized bald eagle egg and plasma concentrations from Lake Superior and Huron were one to three orders of magnitude higher than concentrations measured in composite lake trout (Salvelinus namaycush) from the same lake, implying that they biomagnify in the environment.

Emerging brominated flame retardants and dechlorane-related compounds in European eels (Anguilla anguilla) from Latvian lakes

Fifteen halogenated flame retardants (HFRs) including seven emerging brominated flame retardants (EBFRs) and eight dechlorane-related compounds (DRCs) were analyzed in eels (Anguilla anguilla) sampled from five Latvian lakes. Out of the seven EBFRs, hexabromocyclododecane (HBCD) and decabromodiphenyl ethane (DBDPE) were found in eels in quantifiable concentrations, up to 6.58 and 33.0 ng g−1 lipid weight (l.w.), respectively. The mean total concentration of DRCs (∑DRC) in the samples was 0.62 ng g−1 l.w. and the geographical distribution of DRC contamination was nearly uniform among the selected lakes. Dechlorane 602 (Dec 602) was the predominant component, whereas the composition of mixture containing syn- and anti-Dechlorane Plus (DP) stereoisomers showed a pronounced enrichment of the anti-DP isomer and was close to the composition of OxyChem® DP commercial product. The determined concentrations of HFRs were lower than in other studies of aquatic biota from Europe and Asia, and the obtained results reflect the acceptable environmental status of Latvian lakes with regard to the total content of HBCD (∑HBCD), considering the environmental quality standards (EQS) stated in the Directive 2013/39/EU. The highest ∑HBCD levels were observed in eels from lakes corresponding to the industrialization of those areas, while the results of principal component analysis (PCA) showed that the concentration of HBCD depended on the particular sampling lake, reflecting non-uniform contamination of the Latvian environment with this EBFR.

Development and optimization of gas chromatography coupled to high resolution mass spectrometry based method for the sensitive determination of Dechlorane plus and related norbornene-based flame retardants in food of animal origin

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.

Current-Use Flame Retardants in the Water of Lake Michigan Tributaries.

In this study, we measured the concentrations of 65 flame retardants in water samples from five Lake Michigan tributaries. These flame retardants included organophosphate esters (OPEs), brominated flame retardants (BFRs), and Dechlorane-related compounds. A total of 59 samples, including both the particulate and the dissolved phases, were collected from the Grand, Kalamazoo, Saint Joseph, and Lower Fox rivers and from the Indiana Harbor and Ship Canal (IHSC) in 2015. OPEs were the most abundant among the targeted compounds with geometric mean concentrations ranging from 20 to 54 ng/L; OPE concentrations were comparable among the five tributaries. BFR concentrations were about 1 ng/L, and the most-abundant compounds were bis(2-ethylhexyl) tetrabromophthalate, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate, and decabromodiphenyl ether. The highest BFR concentrations were measured in either the IHSC or the Saint Joseph River. The dechlorane-related compounds were detected at low concentrations (<1 pg/L). The fraction of target compounds in the particulate phase relative to the dissolved phase varied by chemical and tended to increase with their octanol-water partition coefficient. The chemical loading from all the five tributaries into Lake Michigan were <10 kg/year for the BFRs and about 500 kg/year for the OPEs.

Environmental exposure to a major urban wastewater effluent: Effects on the energy metabolism of northern pike

Municipal wastewater effluents (MWWEs) consist of dynamic and complex mixtures of chemical and biological compounds that can alter the health of exposed aquatic organisms. Disturbance of energy metabolism has been reported in fish exposed to MWWEs. However, there is a scarcity of knowledge on the physiological events leading to perturbation of energy balance and thyroid regulation, and associated lipid metabolism. The objective of the present study was to use a set of biomarkers, from gene transcription to body condition, to investigate the effects of a chronic environmental exposure to a major primary MWWE on fatty acid metabolism and thyroid hormone levels in northern pike (Esox lucius) collected from the St. Lawrence River near Montreal (QC, Canada). The exposure of pike to MWWE was examined through determination of a suite of persistent and bioaccumulative halogenated flame retardants in liver as this effluent is a known regional source for these chemicals. Greater hepatic concentrations of polybrominated diphenyl ethers (PBDEs, range: 29.6–465ng/g w.w. and 88.8–823ng/g w.w. in females and males, respectively) and other halogenated flame retardants (e.g., dechlorane-related compounds) were determined in fish collected downstream of the MWWE’s point of discharge relative to the upstream site. This exposure in male pike was associated with decreased acyl-coA oxidase (acox1) and fatty acid synthase (fasn) mRNA levels as well as a decreased acyl-coA oxidase (ACOX) activity in liver. In female pike, MWWE exposure was associated with lower circulating free and total triiodothyronine (T3) levels and a tendency for greater total lipid percentages in liver. Present findings provide evidence that chronic exposure of a top predator fish to MWWE can be related to gender-specific effects on fatty acid metabolism and thyroid hormone homeostasis, and highlight the need for further investigation.

Bioaccumulation of Dechloranes, organophosphate esters, and other flame retardants in Great Lakes fish.

We measured the concentrations of 60 flame retardants (and related compounds) in fish samples collected in the Great Lakes basin. These analytes include dechlorane-related compounds (Decs), organophosphate esters (OPEs), and brominated flame retardants (BFRs). Composite lake trout (Salvelinus namaycush) or walleye (Sander vitreus, from Lake Erie) samples were collected (N=3 for each lake) in 2010 from each of the five Great Lakes (a total of 15 samples). Among the dechlorane-related compounds, Dechlorane, Dechlorane Plus, Dechlorane-602, Dechlorane-603, and Dechlorane-604 (with zero to three bromines and with four chlorines) were detected in >73% of the fish samples. The concentrations of some of these dechlorane-related compounds were 3-10 times higher in Lake Ontario trout than in fish from the other four lakes. Tris(1-chloroisopropyl) phosphate, tri-n-butylphosphate, tris(2-chloroethyl)phosphate, and triphenyl phosphate were found in >50% of the fish samples. Polybrominated diphenyl ethers (PBDEs) were the most abundant of the flame retardants in fish, with a mean concentration of 250ng/g lipid. Our findings suggest that the Decs and BFRs with 3-6 bromines are more bioaccumulative in the fish than the OPEs and high molecular weight BFRs.