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(80-21) Theoretical model for hazard assessment to organochlorine compounds in Mediterranean striped dolphin . Marsili, Letizia*,1, D'Agostino, Antonella2, Neri, Giovanni1, Fossi, M. Cristina3, 1 Department of Environmental Sciences, Siena University, Via Mattioli 4, Siena, Italy2 Siena University, P.zza S. Francesco, Siena, Italy3 Messina University, Messina, Italy ABSTRACT- Many studies document the chemical stress related to organochlorine xenobiotics in stranded and free-ranging Mediterranean cetaceans but there does not exist a statistical evaluation of the real hazard of these compounds to the marine mammals. Fat-soluble contaminants usually build up in blubber, which is metabolised only during illness, pregnancy, lactation, migration or food scarcity; the stored contaminants are mobilised along with fat reserves. The largely teutophagous striped dolphin ( Stenella coeruleoalba) is known to accumulate in its blubber very high levels of liphophilic substances as organochlorine compounds (OCs). The aim of this study was to establish a theoretical model to evaluate the risk of HCB, DDTs and PCB congeners, in specimens of Mediterranean striped dolphins. Using a mathematical formula resulting from the knowledge of the length and age of 62 stranded specimens, it was possible to estimate the age of the striped dolphins, fixing physical maturity at ten years. Afterwards, all individuals are considered as adult. This valuation was very important for the discussion of possible differences in contaminant burden between males and females. The differences in OC levels in the blubber from stranded and free-ranging specimens allows us to assess the hazard of different chlorinated xenobiotics in this species of Mediterranean cetaceans, taking the living population as a control sample, and considering these animals to be in good health. For the highest toxic compounds, with teratogenic, mutagenic, carcinogenic and estrogenic capacity, the level beyond which there can be toxicological risk for the striped dolphin, is indicated. Key words: Mediterranean Sea, Cetaceans, Stenella coeruleoalba , OCs |
