Bioaccumulation of platinum group metals in dolphins, Stenella sp., caught off Ghana

Abstract

Platinum group metals (PGMs) concentrations were measured in the tissues= of dolphins (Stenella sp.) caught along the Ghanaian coastline. Tissues from specimens caught by fishermen from Dixcove, western Ghana, were analysed in 2006 for palladium (Pd), platinum (Pt) and rhodium (Rh) using the Neutron Activation Analysis (NAA) analytical technique. Elevated PGM levels were found in the liver, with fresh weight ranges of 0.040–0.481 µg g^–1 for Pd, 0.239–0.946 µg g^–1 for Pt, and 0.011–0.037 µg g^–1 for Rh, supporting other reports of PGM accumulation. This is the first study to show the accumulation of PGM in marine mammals, although the sources of this pollution are not clear and therefore need to be investigated further. The presence of the PGM is very significant, since dolphin meat (‘kako') is consumed in Ghana. This presents a health risk, due to a possible accumulation of PGMs in humans.

Keywords: catalytic converters; kako; marine mammals; Neutron Activation Analysis; platinum group metals; Pra Estuary; vehicular emissions

African Journal of Aquatic Science 2008, 33(3): 255–259