Determination of heavy metals (cd and pb) in bivalve mollusks of commercial interest (anudara tuberculosa and a. Grandes) from puerto el morro, Ecuador.

Abstract

The presence of heavy metals in concentrations that exceed the limits allowed by national and international environmental legislation alters the balance of an ecosystem and although there is a release of heavy metals by natural means, most of it is caused by anthropogenic actions. This research determined the concentrations of cadmium and lead in two species of mollusks of commercial importance: black conch (Anadara tuberculosa) and mule's foot (A. grandis) and in water and sediment samples from the surrounding habitat of these organisms. The results revealed that the concentration of cadmium and lead in water at stations 4, 5 and 6 exceed the values ​​described in Ecuadorian environmental legislation and in sediment the presence of cadmium is more notable because they exceed the values ​​of the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life whose value is 0.676 ppm and the average value quantified in this research was 6.92 ppm. In Ecuador there are no health regulations that establish limits for metal content in bivalve mollusks, however in a USAID study (2009) concentrations lower than 0.1 ppm for cadmium and 0.9 ppm for lead were found, while in the present work an average of 4.24 and 4.01 ppm of cadmium and 3.37 and 2.62 ppm of lead were found for A. tuberculosa and A. grandis respectively, which shows a high concentration of these toxic elements in the organisms studied.