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 fr om the Southern Atlantic coasts was determined by atomic absorption spectro metry. Algal population samples of Ulva lactuca, Enteromorpha prolifera and Porphyra columbina from Gulf San Jorge, Argentina, were collected, composi ted and pooled. Two stations with different exposure degree to human activi ties, Punta Borja and Punta Maqueda, were selected as sampling points. Free ze-dried algal powders of entire plants were digested in a microwave oven b efore spectroscopic analysis. This sample preparation program allowed the d etection of lower levels of metals than the conventional wet digestion proc edure. The content of total cadmium, lead, chromium, copper and zinc in fil tered seawater from the collection sites was also determined in order to st udy metal concentration and distribution in the different algal species. Ta king into account their toxicities, operational speciation of cadmium and l ead was also carried out in order to compare metal accumulation in seaweeds under different environmental conditions. (C) 1999 Elsevier Science Ltd. A ll rights reserved.