Determining the microbial and chemical contamination in Ecuador’s main rivers

Abstract

One major health issue is the microbial and chemical contamination of natural freshwater, particularly in Latin American countries, such as Ecuador, where it is still lacking wastewater treatment plants. This study analyzed the water quality in twelve rivers of Ecuador (Coastal, Andean, and Amazonian regions). All rivers showed levels of E. coli and total coliforms above the maximum limit according to International and Ecuadorian legislations. The most polluted rivers were Zamora, Esmeraldas and Machángara. Also, E. coli pathotypes were found in six rivers. Several physicochemical and metal parameters were detected in high levels, such as CODTOTAL (in eight rivers), TSS (in six rivers), TS (in two rivers), Al (in nine rivers), Zn (in eight rivers), Pb (in three rivers), Cu (in three rivers), Fe (in two rivers), and Mn (in Machángara River). Our results agree with other studies in Latin America (such as Colombia, Brazil, and Peru) reporting similar contamination in water resources used for agriculture, livestock, and human consumption. Overall, Guayas, Guayllabamba, and Machángara Rivers showed the highest levels of physicochemical parameters (such as CODTOTAL and TSS) and metal concentrations (such as copper, zinc, aluminum, iron, and manganese). Further studies should evaluate contamination sources and public health impact.

Comments on the reduction in emerging contaminants in water samples from the Esmeraldas coast (Ecuador)

“…The relationship of Enterococcus faecium with faecal contamination can support the thesis that Ecuador rivers may be possible sources of this Gram-positive cocci, as recent research has reported that coliforms are above the maximal threshold established by USA, European and Brazilian guidelines ( Vinueza et al, 2021 ). Moreover, it is possible that other bacterial species, such as Rhodococcus ruber , which easily grows on plastic elastomers (usually polluting seawater and shores), participated in degrading pharmaceuticals available as ECs, for example diclofenac ( Mor and Sivan, 2008 ; Ivshina et al, 2019 ).…”

Assessment of spatiotemporal variability of bacterial pollution in Darbandikhan Lake and its tributaries in the Kurdistan Region of Iraq

“…Coliforms were recorded in the Diyala River during the winter [24], at the Al-Azizziyah site in the Tigris River [26] and Tigris River near the water purification stations within Baghdad Province [23]. Coliforms were recorded in the Southern Gulf of Lake Tana [22], in Mariout lake in Egypt [37], Ecuador's main rivers due to untreated sewage, animal wastes and population activities [38].…”

Native microalgal-bacterial consortia from the Ecuadorian Amazon region: an alternative to domestic wastewater treatment

“…Domestic and industrial WW effluents are released through the public sewer system directly to freshwater bodies without any treatment ( Leon et al, 2020 ). The latter serve as primary sources of fresh water in rural areas for domestic activities such as personal hygiene, laundry, food preparation, and drinking ( SENAGUA, 2016 ; Vinueza et al, 2021 ). Consequently, there is a pressing need to shift the paradigm of wastewater management from one that is disposable to a model that is treatable, reusable, recyclable, and geared toward resource recovery ( Khan et al, 2018 ).…”