engleski

Persistent Organic Pollutants in the European Eel from the Karstic River (Raša River, Croatia)

Polybrominated diphenyl ethers (PBDEs) and organochlorinated (OC) compounds such as polychlorinated biphenyls (PCBs) and DDT isomers are omnipresent in aquatic environments as a consequence of current anthropogenic activities or their use in the past. Due to their specific life cycle, eels are regularly used for biomonitoring contaminant concentrations reflecting environmental burden. Monitoring levels of pollutants in eels is important because it is suspected that they have contributed to the decline of the eel population over the last few decades, as well as because of the impact on human health, as eels are widely included into typical diets among people living in the area of their habitat. Persistent organic compounds (POPs) – PBDE congeners (BDE–28, −47, −99, −100, −153, −154, −183), indicator PCB congeners (PCB−28, −52, −101, −118, −138, −153, −180), and three DDT-type compounds (DDT, DDD, DDE) were analysed in 33 European eels (Anguilla anguilla) caught in the upper (S1) and middle (S2) course of the Raša River, an eastern Adriatic karstic river. Microwave-assisted extraction was used as the extraction technique followed by GC-µECD. According to the results, a low level of PBDE contamination of eels was observed, with a median total concentration (∑PBDE) of 1.76 ng g-1 lipid weight (lw) and 2.02 ng g-1 lw at locations S1 and S2, respectively. BDE-47 was a dominant congener in the samples in which it was detected, accounting for more than 50% to the ∑PBDE in 75% of all eel samples, followed by BDE-100. A relatively wide range of total PCB concentrations was detected, with a median of 29.3 ng g-1 lw and 46.2 ng g-1 lw at S1 and S2, respectively. PCB-138 and -153 were the predominant congeners in analysed eel samples, followed by PCB-180. Hexachlorobiphenyls mainly contribute the most to PCB levels in eels, but the same is also typical for different marine organisms in the Adriatic Sea. The analysed DDT- type compounds were present in all eel samples from the Raša River. The median of their total concentration was 37.3 ng g-1 lw and 53.8 same is also typical for different marine organisms in the Adriatic Sea. The analysed DDT-type compounds were present in all eel samples from the Raša River. The median of their total concentration was 37.3 ng g-1 lw and 53.8 ng g-1 lw, at locations S1 and S2, respectively. DDE was the predominant compound among all of the targeted analytes. Concentrations of targeted organic contaminants were significantly positively correlated with length, weight and the relative condition factor of eels, and even to a greater extent with the lipid content of eels. Since all of the analysed eels were in the yellow stage, such results were expected, because in this life stage, they strongly accumulate lipophilic contaminants due to their high lipid content and sedentary lifestyle. Although the OC compounds included in this study were banned decades before PBDEs were, they were still detected in higher concentrations in eels from the Raša River, confirming their persistence in biota. Generally, the levels of organic contaminants in eels measured in our study were at the lower end of levels reported for eels across Europe.

eel, persistent organic pollutants, river, PBDEs, PCBs, DDT isomers

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