Determinación de metales pesados en la cobertura vegetal de suelos agrícolas en las parroquias: La Matriz y San Felipe de Rumipamba Quero-2023

Abstract

The objective of this study was to determine the level of contamination by heavy metals (Pb, Cd, As, Ni, Hg) in the vegetative cover of agricultural soils caused by the application of agrochemicals in the parishes of La Matriz and San Felipe de Rumipamba in the Quero canton, in the province of Tungurahua. A simple random sampling was carried out, and the sampling points were identified through the collection of bibliographic information and field trips in which the study area was explored, thus allowing the establishment of 10 strategic points where the presence of anthropogenic and agricultural activities was verified, thus finding Potato, corn, broad bean, carrot and onion crops, as well as found plant species typical of the area. A representative sample of 2 kg was taken from each of these samples and through laboratory analysis parameters such as pH, electrical conductivity, micronutrients (Fe, Mn, Zn, Cu) and the concentration of heavy metals (Pb, Cd, As, Ni, Hg). The vegetation cover samples presented an acidic pH and an electrical conductivity that fluctuates between 4.61 and 5.92 mS/cm, which indicates a high salinity content; these conditions favoured the solubility and mobility of the contaminants. Therefore, there was a better assimilation by the plants. Heavy metals (apart from Pb) and micronutrients, according to the NTE INEN-CODEX, CODEX ALIMENTARIUS and international regulations, exceed the maximum permissible limits established in said regulations. Based on these results, contamination and mobility of heavy metals from the soil to its plant cover are evidenced, which implies possible contamination of the soil, an alteration of soil fertility, and an affectation to the growth and development of plants, which entails a risk to the health of consumers of the studied products.