Human health risk assessment by exposure to contaminants from an urban reservoir: a pilot study in the Madin Dam (México)

Abstract

Water contamination greatly impacts human health. The Metropolitan Area of the Valley of Mexico (MAVM) is one of the most densely inhabited and polluted places globally, with a significant problem being the rising water demand. The research aims to assess the impact of metals such as iron, aluminum, lead, cadmium, and total chromium, among others, in the water of the Madin Dam, a key reservoir in the area's water supply. The assessment concentrated on individuals who were in good health and had been exposed to these pollutants. It analyzed factors such as levels of oxidized proteins; changes in the function of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase); and their genetic expression, the occurrence of micronuclei, and the amount of DNA methylation. The findings were linked to the metals present in the MAVM drinking water, and the risk was evaluated. The research included four groups: two associated with the Madin Dam, consisting of persons living nearby or using water from the reservoir, and two acting as a control. The study highlighted a significant link between long-term exposure to pollutants in drinking water and elevated levels of oxidized proteins, increased micronuclei frequency, changes in antioxidant enzyme activity and gene expression, and a higher percentage of 5-methylcytosine. The risk assessment showed that people who use drinking water and/or consume fish from Madin Dam have a potential higher risk associated with metal contamination.

Keywords: DNA methylation; Drinking water pollution; Genotoxic effect; Human health effects; Oxidative stress; Risk assessment.