Instituto de Microbiología, Colegio de Ciencias Biológicas y Ambientales (COCIBA), Universidad San Francisco de Quito (USFQ), Diego de Robles y Vía Interoceánica, Campus Cumbayá, Casilla Postal 17-1200-841, Quito 170901, Ecuador.
Colegio de Ciencias e Ingeniería, El Politécnico, Instituto Biósfera, Universidad San Francisco de Quito, Quito 170901, Ecuador.
Int J Environ Res Public Health. 2020 Jul 14;17(14):5048. doi: 10.3390/ijerph17145048.
Contamination of natural water sources is one of the main health problems worldwide, which could be caused by chemicals, metals, or microbial agents. This study aimed to analyze the quality of 18 rivers located in Quito, the capital province of Pichincha, Ecuador, through physico-chemical and microbial parameters. The and total coliforms assessments were performed by a counting procedure in growth media. Polymerase chain reaction (PCR) was realized to detect several microbial genera, as well as , two parasites ( and spp.) and pathotypes: enterohemorrhagic (EHEC), enteroaggregative (EAEC), enteroinvasive (EIEC) and enteropathogenic (EPEC). Additionally, physico-chemical parameters and major and trace metals were analyzed in each surface water sample. Our results demonstrated that most of the rivers analyzed do not comply with the microbial, physico-chemical, and metal requirements established by the Ecuadorian legislation. In terms of microbial pollution, the most polluted rivers were Monjas, Machángara, Pisque, and Pita Rivers. Furthermore, three out of four analyzed pathotypes (EIEC, EHEC, and EAEC) were detected in certain rivers, specifically: Monjas River showed the presence of EIEC and EHEC; in the Machángara River, EAEC and EIEC were detected; and finally, EIEC was present in the Guayllabamba River. Several physico-chemical parameters, such as pH, COD, and TSS values, were higher than the Ecuadorian guidelines in 11, 28, and 28% of the rivers, respectively. Regarding heavy metals, Zn, Cu, Ni, Pb, Cd, and Mn surpassed the established values in 94, 89, 61, 22, 22, and 17% of the rivers, respectively. Machangara River was the only one that registered higher Cr concentrations than the national guidelines. The values of Al and Fe were above the recommended values in 83 and 72% of the rivers. Overall, based on the physical-chemical and microbiological parameters the most contaminated rivers were Machángara and Monjas. This study revealed severe contaminations in Ecuadorean Rivers; further studies should evaluate the sources of contamination and their impact on public health.
天然水源的污染是全球主要的健康问题之一，其可能由化学物质、金属或微生物制剂引起。本研究旨在通过理化和微生物参数分析位于厄瓜多尔皮钦查省省会基多的 18 条河流的水质。通过在生长培养基中的计数程序进行 和总大肠菌群的评估。聚合酶链反应 (PCR) 用于检测几种微生物属，以及 和两种寄生虫（ 和 spp.）和 型：肠出血性 （EHEC）、肠聚集性 （EAEC）、肠侵袭性 （EIEC）和肠致病性 （EPEC）。此外，还分析了每个地表水样本的理化参数以及主要和微量元素。我们的研究结果表明，大多数分析的河流都不符合厄瓜多尔法规规定的微生物、理化和金属要求。在微生物污染方面，污染最严重的河流是 Monjas、Machángara、Pisque 和 Pita 河。此外，在所分析的四个 型中的三个（EIEC、EHEC 和 EAEC）在某些河流中被检出，具体而言：Monjas 河显示存在 EIEC 和 EHEC；Machángara 河中检出 EAEC 和 EIEC；最后，Guayllabamba 河中存在 EIEC。11%、28%和 28%的河流的 pH、COD 和 TSS 值等理化参数高于厄瓜多尔的指导值。关于重金属，锌、铜、镍、铅、镉和锰在 94%、89%、61%、22%、22%和 17%的河流中超过了规定值。Machangara 河是唯一铬浓度超过国家指导值的河流。83%和 72%的河流中铝和铁的含量高于推荐值。总体而言，根据理化和微生物参数，污染最严重的河流是 Machángara 和 Monjas。本研究揭示了厄瓜多尔河流的严重污染；应进一步研究评估污染来源及其对公共健康的影响。
