Toxic textile dyes accumulate in wild European eel Anguilla anguilla.

Dyes are used to stain inks, paints, textile, paper, leather and household products. They are omnipresent, some are toxic and may threaten our environment, especially aquatic ecosystems. The presence of residues of sixteen dyes (triarylmethanes, xanthenes, phenothiazines and phenoxazines) and their metabolites was analyzed in muscle tissue samples of individual yellow-phased European eels (Anguilla anguilla) from 91 locations in Belgian rivers, canals and lakes sampled between 2000 and 2009 using ultra performance liquid chromatography-tandem mass spectrometry. Eel was contaminated by dyes in 77% of the sites. Malachite Green, Crystal Violet and Brilliant Green were present in 25-58% of the samples. Dye occurrence was related to the distribution of textile and dye production industries. This field study is the first large-scale survey to document the occurrence of artificial dyes in wildlife. Considering the annual amounts of dyes produced worldwide and the unintentional spillage during their use, our observations warrant additional research in other parts of the world. The presence of these highly toxic dyes in the European eel may form an additional threat to this critically endangered species. The contaminated eels should be considered as not suitable for consumption.

Organophosphorus flame retardants in the European eel in Flanders, Belgium: Occurrence, fate and human health risk.

The present study investigated the levels, profiles and human health risk of organophosphorus flame retardants and plasticizers (PFRs) in wild European eels (Anguilla anguilla) from freshwater bodies in the highly populated and industrial Flanders region (Belgium). Yellow eels (n=170) were collected at 26 locations between 2000 and 2009 and for each site, muscle samples of 3-10 eels were pooled and analyzed (n=26). Muscle lipid percentages varied widely between 2.4% and 21%, with a median value of 10%. PFRs were detected in all pooled samples in the order of tris-2-chloroisopropyl phosphate (TCIPP)>triphenyl phosphate (TPHP)>2-ethylhexyl diphenyl phosphate (EHDPHP)>tris-2-butoxyethyl phosphate (TBOEP)>tris-2-chloroethyl phosphate (TCEP)>tris-1,3-dichloro-2-propyl phosphate (TDCIPP). The median sum PFR concentration for all 26 sites was 44 ng/g lw (8.4 ng/g ww), and levels ranged between 7.0 and 330 ng/g lw (3.5 and 45 ng/g ww). Levels and profiles of PFRs in eels showed that sampling locations and river basin catchments are possible drivers of spatial variation in the aquatic environment. Median PFR concentrations were lower than those of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). No correlation was observed between the PFR concentrations and lipid contents, suggesting that the accumulation of PFRs is not primarily associated with lipids. Human exposure to PFRs, due to consumption of wild eels, seems to be of minor importance compared to other potential sources, such as inhalation and ingestion of indoor dust. Nevertheless, considering the very limited data available on PFRs in human dietary items and their expected increasing use after the phase out of PBDEs and HBCDs, further investigations on PFRs in biota and human food items are warranted.

Assessment of persistent brominated and chlorinated organic contaminants in the European eel (Anguilla anguilla) in Flanders, Belgium: Levels, profiles and health risk.

Pooled yellow European eel (Anguilla anguilla (L.)) samples, consisting of 3-10 eels, collected between 2000 and 2009 from 60 locations in Flanders (Belgium) were investigated for persistent contaminants, such as polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane and its metabolites (DDTs). The current study expands the knowledge regarding these contaminant concentrations, their patterns and distribution profiles in aquatic ecosystems. PBDEs, HBCDs, PCBs, and DDTs were detected in all eel samples and some samples had high concentrations (up to 1400, 9500, 41,600 and 7000ng/g lw, respectively). PCB levels accounted for the majority of the contamination in most samples. The high variability in PBDE, HBCD, PCB and DDT concentrations reported here is likely due to the variety in sampling locations demonstrating variable local pollution pressures, from highly industrialised areas to small rural creeks. Among PBDEs, BDE-47 (57% contribution to the sum PBDEs), -100 (19%) and -99 (15%) were the predominant congeners, similar to the composition reported in the literature in eel samples. For HBCDs, α-HBCD (74%) was predominant followed by γ-(22%) and ß-HBCD (4%) isomers in almost all eel samples. CB-153 (19%) was the most dominant PCB congener, closely followed by CB-138 (11%), CB-180 (9%), CB-187 (8%) and CB-149 (7%). The contribution to the total human exposure through local wild eel consumption was also highly variable. Intake of PBDEs and HBCDs, through consumption of wild eel, was below the RfD values for the average population (consuming on average 2.9g eel/day). At 16 out 60 sites, eels exceeded largely the new EU consumption threshold for PCBs (300ng/g ww for the sum of 6 indicator PCBs). The current data shows an on-going exposure of Flemish eels to PBDEs, HBCDs, PCBs and DDTs through indirect release from contaminated sediments or direct releases from various industries.

Multi-dye residue analysis of triarylmethane, xanthene, phenothiazine and phenoxazine dyes in fish tissues by ultra-performance liquid chromatography-tandem mass spectrometry.

Beside the possible illegal use of malachite green in aquaculture, other familiar dyes could also been applied by fraudulent producers due to their antiseptic and antibacterial activity. In this contribution, a new sensitive multi-residue method was developed to determine triarylmethane, xanthene, phenothiazine and phenoxazine dyes in fish by ultra-performance liquid chromatography-tandem mass spectrometry. Samples were extracted with acetonitrile, followed by an oxidation step using 2,3-dichloro-5,6-dicyanobenzoquinone. Further clean-up was performed by tandem solid phase extraction using weak and strong cation exchange cartridges. Extracts were analysed by UPLC-MS(n) operating in the positive electrospray ionisation mode (ESI+). The fourteen dyes were separated within only 12min on a C18 BEH column using 1mM ammonium acetate in water at pH 4.5 and acetonitrile as mobile phases at a flowrate of 0.4mLmin(-1). The presented method was validated as defined by the European Union and scientific literature. Good linearity (R ≥0.99 and goodness-of-fit (g) ≤10%) was achieved over the tested concentration range (0.25-2ngg(-1)). Limit of quantification was 0.25ngg(-1) for all dyes, with a signal-to-noise ratio of at least 10/1. This is at least 5 to 10 times lower than previous published methods. Limits of detection were all <0.1ngg(-1). Precision and trueness fell within the criteria requested by the EC requirements for this concentration range. Decision limit (CCα) and detection capability (CCß) were all <1 and <0.25ngg(-1), respectively. Due to background levels of the xanthene dyes, the two rhodamine dyes could only be determined above 0.75ngg(-1). For these dyes, the method can only be used for screening purposes. To show the applicability of the method, a monitoring study was performed to investigate the occurrence of artificial dyes in wildlife European eel in Flemish rivers.

Are persistent organic pollutants and metals in eel muscle predictive for the ecological water quality?

Relationships between the presence of PCBs, OCPs and metals in aquatic ecosystems and the ecological water quality were investigated by combining datasets of long-term monitoring of chemicals in European eel (Anguilla anguilla, N = 1156) in Flanders (Belgium) and the Ecological Quality Ratio (EQR), based on the assessment of fish assemblages at 185 locations. For most pollutants, EQR scores were lower when pollutant levels were higher. Threshold concentrations for a good quality could be formulated for PCB's, most metals and OCPs. Mixed models suggested that the ecological water quality was significantly correlated with the presence of PCBs. However, the low R(2) indicates that other environmental pressures may significantly influence the biotic integrity of fish communities. Empirical data and their analyses are essential to enable defining threshold values of bioaccumulated levels to allow better protection of the aquatic environment and its biota through associated food webs as demanded by the Water Framework Directive.

The European eel quality database: towards a pan-European monitoring of eel quality.

The stocks of the European eel Anguilla anguilla are in decline and there is an increasing awareness that poor health status due to contaminants and/or diseases might be a key element in this decline and might be a hindrance to recovery. Many countries have started compiling data on the health status of eels in their water bodies. Objectives for these monitoring actions are diverse and there is a large amount of information collected by EU member countries. However, this information is widely scattered over Europe in agencies, institutes or universities. As there is a growing need to collect and report on data on the health status of the eel on international level, the Joint EIFAC/ICES Working Group on Eels initiated in September 2007 the set up of an European Eel Quality Database to collect recent data of contaminants and diseases over the distribution area of the eel. This paper describes the aim, the set up and future development of the database in order to give it greater publicity and to call on scientists or managers to submit data on eel health status. The database represents now the first comprehensive pan-European compilation of eel health data, including data from over 10,000 eels from approximately 1,200 sites over 14 countries. Preliminary work has indicated a number of shortcomings and future developments will be needed. Guaranteeing further development of the database, harmonisation of methods, quality assurance, and setting up harmonised eel monitoring strategies over Europe will be a great challenge and will need pan-European cooperative work.

What can we learn from monitoring PCBs in the European eel? A Belgian experience.

Between 2000 and 2007 pooled muscle tissue samples of the European eel (Anguilla anguilla) from 48 sites in Flanders (Belgium) were analysed for 30 polychlorinated biphenyl (PCB) congeners. There was a large variation between individual sites (range 11-7752 ng/g wet weight (ww) for the sum of the ICES 7 PCBs), eels from the River Meuse basin (mean 1545 ng/g ww) being considerably more polluted than those from the River Scheldt (615) and IJzer (61) basins. Overall, PCB 153, PCB 138 and PCB 180 were the most prominent congeners, however PCB patterns varied between the monitored locations. Analysis of the weight percentage of congeners demonstrates obvious differences in PCB composition between sites, indicating differential sources of pollution. Due to the variation in patterns, atmospheric fallout does not seem to be the main source of the PCB spread, but instead both local and upstream sources linked to industrial activities seem to be the main cause for PCB presence in Flanders. Considering the levels of the Sum 7 PCBs, eels are not compliant with the Belgian legal limits for consumption (75 ng/g ww) in 71% of the sites. Regular consumption of eels from polluted sites leads to a considerable excess of the WHO Acceptable Daily Intake value. Consumption of wild eels should by all means be prevented, as it presents risks for human health, especially for local anglers consuming their catch.

Spatial variations in the levels and isomeric patterns of PBDEs and HBCDs in the European eel in Flanders.

Pooled yellow eel (Anguilla anguilla L.) samples, consisting of 3-10 eels, from 50 locations collected in the period 2000-2006 were used to assess the pollution with PBDEs and HBCDs in Flemish waters (Belgium). Results from this monitoring network are presented and the spatial aspect throughout Flanders is included, linking POP levels to the industrial characteristics of the different sampling locations. The following PBDE congeners were measured using GC/MS: 28, 47, 49, 66, 85, 99, 100, 153, 154, 183 and 209. Concentrations of summation sigmaPBDE ranged between 10 and 5811 ng/g lipid weight (lw) with a median value of 81 ng/glw. BDE 47 dominated the PBDE profile in the majority of the eel samples, except for six samples, in which BDE 209 was the dominating congener. These latter samples are probably associated with recent exposure to the Deca-BDE mixture. Three HBCD diastereoisomers (alpha-, beta- and gamma-HBCD) were measured using LC/MS-MS. summation sigmaHBCDs ranged between 16 and 4397 ng/glw, with a median value of 73 ng/glw. alpha-HBCD was the dominant isomer in all eel samples. Sediment concentrations of PBDEs were available from four locations and were used to compare the PBDE profile with those in eel. An important shift in the profile was observed, especially for BDE 209. While BDE 209 was only found in 12 eel samples, it was the dominant congener in all sediment samples. This could be due to its metabolisation or degradation in biota combined with the poor uptake of BDE 209 from sediments and its very low water solubility. No HBCDs were detected in any of the sediment samples. No significant correlation could be found between concentrations of PBDEs in eel and sediment from the same location. Comparison with previous studies shows that PBDE and HBCD levels in Flemish eels have decreased rapidly between 2000 and 2006 at particular sites, but alarming concentrations can still be found at industrialized hot spots. This finding is reflected in the human exposure to PBDEs and HBCDs through eel consumption. For average consumers (2.9 geel/day), intakes ranged between 3 and 2295 ng/day for summation sigmaPBDEs (with a median value of 16 ng/day) and between 3 and 1110 ng/day for summation sigmaHBCDs (with a median value of 18 ng/day), respectively. Additionally, human intakes were calculated for recreational fishermen, eating up to 12 g or 86 geel/day. Intakes of those risk groups were higher in comparison with average consumers and were above reference doses described in literature which may induce adverse effects.

The effects of contaminants in European eel: a review.

European eel (Anguilla anguilla (L.)) stocks are in decline in most of their geographical distribution and their status is considered below safe biological limits. Recently, there is an increasing awareness that spawner quality might be an essential element in the decline of the species since pollution by bioaccumulating chemical substances may have a large impact on the reproduction success of the eel. This review gives an overview of the literature on the effects of contaminants on the European eel and on the consequences on the biology and fitness of the eel in order to document the role of pollution in its decline. A variety of contaminants have been found to affect the eel. These contaminants may cause disturbance of the immune system, the reproduction system, the nervous system and the endocrine system and effects were reported on several levels of biological organization, from subcellular, organ, individual up to even population level. More extensive research is needed in order to evaluate how pollutants are detrimental to eel populations. Getting a comprehensive overview of the quality (including contamination levels, biomarker responses, lipid content and condition) of the silver eel population all over Europe seems to be an essential and urgent objective for the European eel management.