The health risks of Emilio Portes Gil’s population, for the exposition to the Atoyac River pollution in the State of Puebla, was evaluated. The objective was to determine the concentration of nine heavy metals by ingesting water from wells and spri ngs. The chronic daily water intake (CDI), hazard quotient (HQ), hazard index (HI), and carcinogenic risk index (CRI) in adults, teenagers, and children were estimated. The results showed that the concentration of Fe, Al, Ni, and Pb in some of the samples exceeded the recommended standards for human consumption and was significantly higher in the dry season. The hazard index (HI), due to the collective intake of metals, was higher in children (> 50% compared to adults), due to the consumption of spring water in the dry season. Risk of noncancerous diseases was not detected in the long term, since the indices did not exceed the unit (reference value). The carcinogenic risk from oral exposure to Cr (CRIchildren = 3.2 × 10−4), was greater than the acceptable limit (1 × 10−6) in the water spring, and Cr and Pb were the main metals that contributed to the potential health risk of the inhabitants. The study showed the risks by the intake of polluted water from the sources of supply in the region, and that the risk is higher in the dry season (> 100% compared with rainy season).

Abstract:The Atoyac River crosses the metropolitan area of Puebla-Tlaxcala in Mexico and presents a state of pollution that has been scarcely studied. In 2016, the water quality of the river was evaluated based on physicochemical and bacteriological parameters, under the guidelines established for the Maximum Permissible Limit (MPL) for Aquatic Life Protection (ALP) and Agricultural Irrigation (AI). The sampling sites were the Covadonga Dam, the Echeverría Dam, and an irrigation canal. Water from wells and a spring in the Emilio Portes Gil (EPG) population that uses Atoyac water for agricultural irrigation was also analyzed. The data obtained from the river were compared with the 2011 data published in the declaration of classification of Atoyac and Xochiac or Hueyapan and its tributaries. There was a notable increase in hemical oxygen demand (COD) (49%) and in heavy metals with varying percentages. The anoxic condition of the river (mean 1.47 mg of O 2 /L) with large populations of coliform bacteria was demonstrated, 11 pathogenic members of the Enterobacteriaceae were found, and high organic pollution concentrations were shown, particularly during droughts. Irrigation and well water was contaminated with fecal bacteria (104-549 NMP/100 mL), which included pathogens.