Atoyac River Pollution in the Metropolitan Area of Puebla, México

Abstract

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.

Evaluation of Health Risks due to Heavy Metals in a Rural Population Exposed to Atoyac River Pollution in Puebla, Mexico

“…Many people in the village are exposed to these pollutants, since all homes (522 inhabitants) receive water from this source through the pipeline and use it for drinking, cooking, washing, etc. On the other hand, wells are present in 70% of homes, and only in 41% are they used for drinking [8].…”

“…In the metropolitan area of Puebla-Tlaxcala (MAPT), there are hundreds of industries using different processes, with an important proportion of those using chromium compounds for production or manufacturing processes, such as textiles, metalworking, paints, automotive [8,18,21], etc. These, like the rest of the factories, do not treat their wastewater in the proper way to remove heavy metals and other chemical pollutants [7,8].…”

“…In the metropolitan area of Puebla-Tlaxcala (MAPT), there are hundreds of industries using different processes, with an important proportion of those using chromium compounds for production or manufacturing processes, such as textiles, metalworking, paints, automotive [8,18,21], etc. These, like the rest of the factories, do not treat their wastewater in the proper way to remove heavy metals and other chemical pollutants [7,8]. Thus, in this river, the waste of the fourth largest metropolitan area of Mexico (ZMPT) is discharged, and at the same time, agricultural populations like EPG, located in the lower areas of the basin, use the polluted water of the river for the irrigation of their crops [8].…”

“…They receive the service approximately 3 days per week, which is why 70% of the houses have shallow wells (< 20 m). As for the sanitation infrastructure, wastewater is discharged directly into the ravines through small tubes [8].…”

“…[44,45] and the population is exposed to these elements by different routes. The exposure of heavy metals by the consumption of groundwater represents only one of the possible routes of exposure, it is important to consider that these rural populations obtain the water to drink mainly from the wells and springs and not from other sources [8].…”