Cuantificación de indicadores de contaminación fecal en ríos y canales de agua de riego de cinco provincias del Ecuador

Abstract

In Latin American countries, the coverage of Wastewater Treatment Plants (WWTPs) is deficient, causing an increment of chemical and biological pollutants in aquatic natural ecosystems. Thus, the sanitary risks related to unsafe water for the inhabitants is considerable. In Ecuador, it is estimated that 70 percent of superficial water below 2.800 meters-above-sea-level cannot be used for human purposes. Nowadays, few studies about water quality in this country have been made. This investigation was focused on the detection of microbial indicators of fecal pollution (Escherichia coli, coliforms, somatic coliphages, ceftriaxone-resistant-mesophilic bacteria) in selected rivers and irrigation channels of five provinces of Ecuador. The anthropogenically impacted points Machángara river (Pichincha) and Ambato-Huachi-Pelileo irrigation channel (Tungurahua) presents the highest levels of biological pollution. In addition, the irrigation channels Ambato-Huachi-Pelileo (Tungurahua) and Latacunga-Salcedo-Ambato (Cotopaxi) shown increased ratios of microorganisms with resistance phenotype to a clinically relevant antibiotic. These findings are worrying because demonstrates the high influence of human activities in the biological quality of the rivers and irrigation channels in Ecuador. Complementary studies are needed to take opportune measures aimed to improve the sanitary conditions of water in Ecuador.