Risk Assessment of the Drinking Water Samples in the Rural Area from MG, Brazil

Abstract

Water bodies are subject to contamination, whether diffuse or punctual, of natural or anthropogenic origin. Degradation of water resources can adversely affect human health, the development of industrial and agricultural activities, and thus generate significant impacts in the social, economic and environmental spheres. Despite the recognized importance of water resources, it has been significantly contaminated by toxic metals from industrial, agricultural, mining or even lithogenic processes. This study aimed to evaluate water quality through physical–chemical, microbiological and metal analysis parameters. The physical–chemical parameters analyzed were: pH, turbidity and temperature. Microbiological analysis was performed by determining the presence of total and thermotolerant coliforms through multiple tube methods and the most probable number. The metals were identified and quantified by inductively coupled plasma mass spectrometry. Among the 36 analyzed points, the following results were observed: 11 points presented the pH value below the acceptable limit; 21 points presented alteration in relation to turbidity; 16 points presented positive values for thermotolerant coliforms. Among the 24 metals analyzed, only 4 presented alterations when compared to the limits required by the legislation; they are mercury, aluminum, manganese and iron. Arsenic, although it has values within the parameters, has high toxicity and, for this reason, the value of the risk quotient was also analyzed. It was verified that in 15 points, of the 36 analyzed, there is a potential risk to non-carcinogenic human health; however, the population of this region is at risk of exposure to the toxic metals effects.