Heavy metal contamination and impact on benthic organisms in "Cerrito de los Morreños", Gulf of Guayaquil, Ecuador.

Abstract

In this work, an evaluation of the levels of heavy metal contamination in the environment of the community "Cerrito de los Morreños", Puná canton, Guayas province is carried out. Thirty surface water samples, 32 sediment samples and 50 samples of organisms (Donax sp.) were collected. The physical parameters were taken in situ. The quantification of heavy metals in water, sediment and organisms was determined using an atomic absorption spectrophotometer.The physical parameters: temperature, salinity and pH, were kept constant. Dissolved oxygen varied according to the tides and, at low tide or low tide, low values were recorded, although they are not considered anoxic. Nutrients showed stable averages. As for the quantification of heavy metals in water, cadmium, copper and nickel were found in low concentrations. In sediments, cadmium, copper, lead, nickel and zinc were present in small concentrations, because they are part of the environment due to the different natural cycles. The presence of lead was not detected in organisms (Donax sp.), but cadmium (3,246 ppm), copper (13,242 ppm), nickel (5,506 ppm) and zinc (47,127 ppm) was detected.The presence of lead in the water samples exceeded the permissible limits according to the water quality criteria of the Unified Text of Environmental Legislation (TU LAS); the other metals were below the acceptable range.