Acumulación de mercurio y plomo, en el bivalvo Anadara tuberculosa, entre los años 2016 y 2018 en la desembocadura del río Dagua, Pacífico Colombiano

Abstract

Pollution due to mercury and lead has caused great concern in international entities due to the loss of biodiversity in coastal ecosystems and damage to health. In order to evaluate the presence of mercury and lead in the mouth of the Colombian Dagua-Pacific river, as it is an ecosystem of great ecological and economic importance for the region, seven samplings were carried out between July 2016 and January 2018, sediment samples were obtained and physicochemical parameters of the water in the area were measured. Specimens of the bivalve, Anadara tuberculosa, were used to determine the concentration of mercury and lead in tissues and for bioassays with mercury, due to its ability to bioaccumulate metals. A mean mercury concentration of 0.57± 0.74 mg/kg and lead 0.87 mg/kg ± 0.68 in sediment were found, with maximum values of 1.96 mg/kg Hg and 2.05 mg/kg Pb. The presence of mercury in sediments and water is positively related to the concentrations of this metal in organisms. Bioassays with the bivalve A. tuberculosa, allowed to conclude that at low mercury exposure concentrations (0.25 ppm), lesions are generated in animal tissue, mainly in sexual cells. The high concentrations of mercury and lead found in the organisms exceed the maximum permitted concentration established in Colombia for mercury (0.5 mg/kg) and lead (0.20 mg/kg). In addition, the contamination factor for mercury (FC =228000 μg/g) and lead (FC =1242.85 μg/g) are considered very high, as is the potential contamination index for mercury (CP=3.44 μg/g). This allows us to infer that the presence of metals in the tissue of these bivalves present in the mouth of the Dagua river can generate alterations in the ecosystem with possible consequences on human health due to the consumption of these foods.