Total arsenic, lead, and cadmium levels in vegetables cultivated at the Andean villages of northern Chile

Various vegetables (broad beans, corn, potato, alfalfa and onion) were sampled in northern Chile, Antofagasta Region. They are the basis of human nutrition in this region and of great relevance to human health. This region is characterized by volcanic events (eruptions, thermal springs, etc.). Most of the vegetables cultivated in this area enter the local markets for a population of approximately 4000 people, whose ancestors were mainly atacamenos and quechuas (local indigenous people). The cadmium and lead in these foods was determined by differential pulse anodic stripping voltammetry (DPASV). Results indicate that the highest concentration of Pb and Cd are in the potato skin, while the edible part of the potatoes contained a lower concentration of these metals. The INAA analyses of As in the vegetables from Socaire and Talabre, two towns located close to active volcanoes (e.g. Lascar), show a very high As content: 1850 mu g/kg in corn (Socaire) and 860 mu g/kg in potatoes (+skin) (Talabre). These values exceed the National Standard fur arsenic (500 mu g/kg) by approximately 400% and 180%, respectively. In general, the data show a concentration of Pb greater than Cd with the potential for some vegetables to accumulate heavy metals. The values, expressed in fresh weight, vary from 0.2 to 40 mu g/g for Cd and from 0.6 to 94 mu g/g for Pb. These concentration intervals, except that of arsenic, are within the recommended standards in the Food Sanitary Regulation (Decree 977), which, expressed as fresh weight, must be equal to or smaller than 500 mu g/kg for Pb. There is no legal standard for Cd. (C) 2000 Elsevier Science B.V. All rights reserved.