Seaweeds in the assessment of heavy metal pollution in the Gulf San Jorge, Argentina

The content of cadmium, lead, chromium, copper and zinc in algal samples from the Southern Atlantic coasts was determined by atomic absorption spectrometry. Algal population samples of Ulva lactuca, Enteromorpha prolifera and Porphyra columbina from Gulf San Jorge, Argentina, were collected, composited and pooled. Two stations with different exposure degree to human activities, Punta Borja and Punta Maqueda, were selected as sampling points. Freeze-dried algal powders of entire plants were digested in a microwave oven before spectroscopic analysis. This sample preparation program allowed the detection of lower levels of metals than the conventional wet digestion procedure. The content of total cadmium, lead, chromium, copper and zinc in filtered seawater from the collection sites was also determined in order to study metal concentration and distribution in the different algal species. Taking into account their toxicities, operational speciation of cadmium and lead was also carried out in order to compare metal accumulation in seaweeds under different environmental conditions.