engleski

Monitoring organochlorines at shellfish aquaculture areas

Marine coastal areas were impacted by various human activities deemed to pose a serious threat to the biotic environment and human health. Taking into account the importance of shellfish aquaculture in Croatia, there was a strong need for the determination of the areas designated as shellfish waters. To obtain water quality data, shellfish aquaculture areas along the eastern Adriatic coast were covered by monitoring activities in autumn 2007 and spring 2008. For target parameters analysis, cultivated mussels (Mytilus galloprovincialis) were collected at 23 locations and Flexopecten proteus, Pecten jacobaeus and oysters Ostrea edulis separately at the other 3 locations. Assessment of organochlorines contamination revealed values usually found in uncontaminated to low contaminated marine coastal areas. Among the chlorinated pesticides, only DDTs (p, p') were found at total level up to 3.9 ng/g dwt with an average value of 1.9 ng/g dwt. All others, such as HCB, lindane, heptachlor, aldrin, dieldrin and endrin were below the limit of detection. Total PCBs (7 congeners) varied in much wider range from 1.1 to 34 ng /g dwt with an average of 29 ng/g dwt. Examination of the contaminants spatial distribution showed differences between investigated sites. Higher organochlorine levels were found at shellfish farms in the northern and particularly in the middle Adriatic coast. This was the most likely the result of untreated or partially treated wastewater discharges into the sea from nearby small towns and/or marinas. Regarding the public health, all organochlorines values were considerably below the permissible levels recommended by Croatian legislation for food. Evaluation of the risks to human health associated with consumption of analysed mussels indicated no health risk for shellfish consumers.

pesticides; PCBs; chemical risk assessment

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