Acumulação de compostos organoclorados (PCBs, DDTs e HCB) em tecido hepático de delfinídeos (Cetacea, Mammalia) do Estado do Rio de Janeiro / Organochlorine compounds accumulation (PCBs, DDTs and HCB) in hepatic tissue of delphinids (Cetacea, Mammalia) from Rio de Janeiro State

AUTOR(ES)
DATA DE PUBLICAÇÃO

2011

RESUMO

Over the past decades the research on marine organisms contamination by organochlorine compounds (OCs) has been intensified, allied to the utilization of some species as sentinels of the environmental quality related to organic pollutants. Among these species, cetaceans stand out as animals that, between other characteristics, have great longevity, high lipid percentage on their tissues and are top predators in food chains, therefore having the tendency to accumulate high OCs levels in their tissues. The present study aimed to determine OCs concentrations from industrial and agricultural sources (PCBs, HCB and DDTs) in hepatic tissue of eight different species of delphinid cetaceans belonging to three different oceanic areas of Rio de Janeiro State, namely, coastal region, continental shelf and oceanic region. The determination was performed in an Agilent 6890 gas chromatograph (GC) connected to an Agilent 5973 mass spectrometer (MS). DDTs (1263617272 ng.g -1 lip.) and PCBs (7648877288 ng.g -1 lip.) values reported here are amongst the highest values ever reported for the taxon. In all areas ΣPCB predominance was observed, followed by ΣDDT and HCB in levels that reflect the highly industrial character of the analyzed region. Amongst PCBs, the largest contribution comes from hexa biphenyls, followed by hepta and penta biphenyls, being the 153, 138 and 180 the main congeners in all areas. The p,pDDE/ΣDp,pDDT ratio was high in all regions (0,9), reflecting an ancient input of the pollutant in the area. Correlations between OCs concentrations and biologic parameters such as age, sex and total body lenght were performed. OCs placental transfer was analyzed in two Sotalia guianensis mother-fetus pairs, showing a higher transfer of compounds with lower log Kow. As expected, a significant difference was found on the contamination profile between species from the different regions, related to source proximity, species-specific characteristics and the species trophic arrangement.

ASSUNTO(S)

cetacea rio de janeiro pcb ddt hcb bioacumulação biomagnificação toxicologia ceetacea rio de janeiro pcb ddt hcb bioaccumulation biomagnification

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