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Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) belong to a group of persistent organic pollutants (POPs), and despite restricted and/or banned production and use, they are still found in all environmental compartments. Because of their high lipophility, they accumulate in the adipose tissue of animals and humans. The Mediterranean blue mussel (lat. Mytilus galloprovincialis) is a well known bioindicator of environmental pollution due to its great capacity to accumulate different contaminants, weak mobility, and wide geographical distribution. In this study we investigated the levels of 17 PCB congeners and 7 OCPs in the edible tissue of mussels collected at two locations (L1-Martinska and L2-Ina-Vinil) on Croatian coast in 2003 and 2008. At L1 PCBs ranged between 0.09 and 12.77 ng/g in 2003 and between 0.05 and 7.45 ng/g dry wt in 2008. The respective ranges for L2 were 0.27-50.67 and 0.16-13.81 ng/g dry wt. OCPs at L1 ranged between 0.11 and 4.34 ng/g in 2003 and between 0.09 and 2.41 ng/g dry wt in 2008. The respective ranges for L2 were 0.31-6.83 ng/g in 2003 and 0.23-4.59 ng/g dry wt in 2008. Analysed compounds showed similar profiles in all four analysed samples. From the OCP group, levels of alpha-HCH were the lowest in all analysed samples, followed by the DDD and HCB (similar levels found). Then followed beta-HCH and gamma-HCH with similar values, and finally DDT and DDE with the highest levels. PCBs also showed similar profiles on both locations in both years. The lowest levels were found for PCBs 114, 74, 157, and 189, while the highest levels were found for PCBs 52, 153, 101, 123, and 118. At both locations, the levels of all analysed compounds had decreased over the five years at same or very similar rate (between 30 and 60 %). The exceptions were beta-HCH and PCB-52 (with 75 % and 78 % decrease at both locations, respectively). The decrease was slower for PCB-28 (11 % at both locations) and α-HCH (18 % at L1 and 26 % at L2). Alpha-HCH/gamma-HCH and DDE/DDT ratios are often used to see if there is a fresh input of gamma-HCH or DDT in the environment. Ratios below 1 indicate fresh contamination. DDE/DDT ratio at L1 was 2.05 in 2003 and 1.62 in 2008 and at L2 1.05 and 0.83. The respective alpha-HCH/gamma-HCH ratios were 0.05 and 0.09 at L1 and 0.08 and 0.15 at L2. All the values obtained for mussels from the two locations on the Croatian coast are orders of magnitude below the Croatian maximum permissible levels (MLP) for PCBs and OCPs in mussels for human use (1, 2) and they do not pose any threat for human health. REFERENCES 1. Anonymous (2005) Legislation on toxins, metals, metalloids and other harmful substances that can occur in food (original in Croatian). Narodne novine 16 2. Anonymous (2007) Legislation on maximum permitted levels of pesticides in food and food for animals (original in Croatian). Narodne novine 119 |
