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Espira LM, Contreras JD, Felix-Arellano EE, Siebe C, Mazari-Hiriart M, Riojas-Rodríguez H, Eisenberg JNS. A comparative analysis of regional infection risk due to wastewater recontamination in the Mezquital Valley, Mexico. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170615. [PMID: 38316303 DOI: 10.1016/j.scitotenv.2024.170615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/30/2024] [Accepted: 01/30/2024] [Indexed: 02/07/2024]
Abstract
Urban wastewater reuse for agriculture provides reliable nutrient-rich water, reduces water stress, and strengthens food systems. However, wastewater reuse also presents health risks and characterizing the spatial dynamics of wastewater can help optimize risk mitigation. We conducted comparative risk analysis of exposure to wastewater in irrigation canals, where we compared those exposed to a) treated vs. untreated wastewater, and b) wastewater upstream vs. downstream from communities in the Mezquital Valley. The canal system with treated wastewater was sampled prior to being treated, directly after treatment, as well as before and after it flowed through a community. Along the canal system that carried untreated wastewater, we sampled before and after a community. We quantified the concentrations of bacterial, protozoal, and viral pathogens in the wastewater. Pathogen concentration data were used to calculate measures of relative risk between sampling points. Wastewater treatment reduced predicted bacterial pathogen infection risk in post-treatment locations (RR = 0.73, 95 % CI 0.61, 0.87), with no evidence of similar reductions in Giardia or viral pathogens (RR = 1.02, 95 % CI 0.56, 1.86 and RR = 1.18, 95 % CI 0.70, 2.02 respectively). Although infection risk decreased further down the canals, infection risk increased for bacterial pathogens after our sentinel community (RR = 1.94, 95 % 1.34, 2.86). For Giardia and viral pathogens infection risk was elevated but not significantly. We found similar evidence for increases in risk when comparing the treated section of the canal system with a canal section whose wastewater was not treated, i.e., the risk benefits of wastewater treatment were lost after our sentinel community for bacteria (RR = 5.27 vs. 2.08 for sampling points before and after our sentinel community respectively) and for Giardia (RR = 6.98 vs. 3.35 respectively). The increase in risk after transit through communities could have resulted from local community recontamination of the treated wastewater stream.
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Affiliation(s)
- Leon M Espira
- Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Jesse D Contreras
- Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Eunice E Felix-Arellano
- Dirección de Salud Ambiental, Instituto Nacional de Salud Pública, Universidad No. 655 Colonia Santa María Ahuacatitlán, Cerrada Los Pinos y Caminera, 62100 Cuernavaca, Morelos, Mexico
| | - Christina Siebe
- Instituto de Geología, Universidad Nacional Autonóma de México, Circuito de la Investigación Científica s/n, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Marisa Mazari-Hiriart
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de Mexico, Circuito Exterior s/n. Anexo Jardín Botanico Exterior, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Horacio Riojas-Rodríguez
- Dirección de Salud Ambiental, Instituto Nacional de Salud Pública, Universidad No. 655 Colonia Santa María Ahuacatitlán, Cerrada Los Pinos y Caminera, 62100 Cuernavaca, Morelos, Mexico
| | - Joseph N S Eisenberg
- Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, United States of America.
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Ginn O, Rocha-Melogno L, Bivins A, Lowry S, Cardelino M, Nichols D, Tripathi SN, Soria F, Andrade M, Bergin M, Deshusses MA, Brown J. Detection and Quantification of Enteric Pathogens in Aerosols Near Open Wastewater Canals in Cities with Poor Sanitation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14758-14771. [PMID: 34669386 DOI: 10.1021/acs.est.1c05060] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Urban sanitation infrastructure is inadequate in many low-income countries, leading to the presence of highly concentrated, uncontained fecal waste streams in densely populated areas. Combined with mechanisms of aerosolization, airborne transport of enteric microbes and their genetic material is possible in such settings but remains poorly characterized. We detected and quantified enteric pathogen-associated gene targets in aerosol samples near open wastewater canals (OWCs) or impacted (receiving sewage or wastewater) surface waters and control sites in La Paz, Bolivia; Kanpur, India; and Atlanta, USA, via multiplex reverse-transcription qPCR (37 targets) and ddPCR (13 targets). We detected a wide range of enteric targets, some not previously reported in extramural urban aerosols, with more frequent detections of all enteric targets at higher densities in La Paz and Kanpur near OWCs. We report density estimates ranging up to 4.7 × 102 gc per mair3 across all targets including heat-stable enterotoxigenic Escherichia coli, Campylobacter jejuni, enteroinvasive E. coli/Shigella spp., Salmonella spp., norovirus, and Cryptosporidium spp. Estimated 25, 76, and 0% of samples containing positive pathogen detects were accompanied by culturable E. coli in La Paz, Kanpur, and Atlanta, respectively, suggesting potential for viability of enteric microbes at the point of sampling. Airborne transmission of enteric pathogens merits further investigation in cities with poor sanitation.
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Affiliation(s)
- Olivia Ginn
- Department of Civil and Environmental Engineering and Earth Science, University of Notre Dame, Notre Dame, Indiana 46656, United States
| | - Lucas Rocha-Melogno
- Department of Civil and Environmental Engineering, and Duke Global Health Institute, Duke University, Durham, North Carolina 27708, United States
- ICF, 2635 Meridian Parkway Suite 200, Durham, North Carolina 27713, United States
| | - Aaron Bivins
- Department of Civil and Environmental Engineering and Earth Science, University of Notre Dame, Notre Dame, Indiana 46656, United States
| | - Sarah Lowry
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Maria Cardelino
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Dennis Nichols
- Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Sachchida Nand Tripathi
- Department of Civil Engineering & Centre for Environmental Science and Engineering, Indian Institute of Technology - Kalyanpur, Kanpur 208016, Uttar Pradesh, India
| | - Freddy Soria
- Centro de Investigación en Agua, Energía y Sostenibilidad, Universidad Católica Boliviana "San Pablo", La Paz 4807, Bolivia
| | - Marcos Andrade
- Laboratory for Atmospheric Physics, Institute for Physics Research, Universidad Mayor de San Andres, La Paz 1995, Bolivia
- Department of Atmospheric and Oceanic Sciences, University of Maryland, College Park, Maryland 20742, United States
| | - Mike Bergin
- Department of Civil and Environmental Engineering, and Duke Global Health Institute, Duke University, Durham, North Carolina 27708, United States
| | - Marc A Deshusses
- Department of Civil and Environmental Engineering, and Duke Global Health Institute, Duke University, Durham, North Carolina 27708, United States
| | - Joe Brown
- Deparment of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, United States
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Fonseca-Salazar MA, Díaz-Avalos C, Rochin-García H, Espinosa-García AC, Mazari-Hiriart M. Risk transfer from a megacity to a peri-urban agricultural community: wastewater reuse and effects on groundwater quality. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:741. [PMID: 34674049 DOI: 10.1007/s10661-021-09520-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
Urban wastewater is a resource that can be reused, but its management must be carefully executed, considering its potential impact on public and environmental health. Unfortunately, marked differences in the quality of treatment, management, collection, and the monitoring of wastewater exist among low-, middle-, and high-income countries. This is the case of the Mezquital Valley, a semi-rural area that is composed of agricultural and industrial communities on the outskirts of Mexico City. For over 100 years, wastewater from Mexico City and its areas of conurbation has been sent to the Mezquital Valley, with few studies having been conducted to assess the existence and severity of bacterial and pathogen infiltration into the local aquifer. In this research, we present an assessment of wastewater infiltration transported from Mexico City, used for irrigation, with potential infiltration into the Mezquital Valley aquifer. We utilized stable isotope analysis of deuterium and oxygen-18 to determine whether a mixture of untreated wastewater from the Mexico City Metropolitan Area (MCMA) flows into the Mezquital aquifer. Also, tests for adenovirus, rotavirus, fecal coliform, fecal enterococci, Giardia lamblia, and Cryptosporidium parvum were employed to determine the presence of fecal indicators and pathogens in different water sources in the study area. The results show the presence of indicators and pathogens in local wells used as water supply in Mezquital Valley. The presence of such indicators suggests that pathogens can reach the water consumed by the inhabitants, posing a hazard to persons exposed to these waters during their normal daily-life activities.
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Affiliation(s)
| | - Carlos Díaz-Avalos
- Departamento de Probabilidad Y Estadística, Instituto de Invsetigaciones en Matemáticas Aplicadas y en Sistemas, UNAM, Mexico City, Mexico.
| | - Hermes Rochin-García
- Posgrado en Ciencias de La Tierra, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ana Cecilia Espinosa-García
- Laboratorio Nacional de Ciencias de La Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marisa Mazari-Hiriart
- Laboratorio Nacional de Ciencias de La Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Lüneberg K, Amábile-Cuevas CF, Mucito-Varela E, Martínez L, Salinas E, López-Vidal Y, Siebe C, Rosas I. Metallo-beta-lactamase-producing Escherichia coli in the sewage of Mexico City: where do they come from? Can J Microbiol 2021; 68:139-145. [PMID: 34662521 DOI: 10.1139/cjm-2021-0284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
While monitoring the presence of antibiotic resistance in municipal wastewater bacteria from Mexico City, five Escherichia coli isolates were found to be resistant to carbapenems, antibiotics of "last resort" used mostly in hospitals. Further analysis revealed that these carbapenem-resistant isolates carried the gene encoding a metallo-beta-lactamase, NDM-5. The gene was found to be beared by a large, ∼145 kb conjugative plasmid, which also carries putative genes encoding resistance to sulfonamides, trimethoprim, tetracycline, ciprofloxacin, and chloramphenicol (although no phenotypic chloramphenicol resistance was detected) and quaternary-ammonium compounds. The plasmid also carried gene mobility determinants, such as integron integrase and two transposases. In addition to the direct public health threat posed by the presence of such multi-resistant organisms in wastewater released into the environment and used for crop irrigation; it is particularly concerning that carbapenem-resistant E. coli is rather rare in Mexican hospitals (<1%), but was found in small, 100 mL samples of municipal wastewater. This suggests that these organisms are under-reported by clinical microbiology laboratories, underlining the usefulness of wastewater monitoring, or that there is an unknown source of such carbapenem-resistant organisms that are being dumped into the wastewater. The source of these bacteria must be assessed and controlled to prevent further spread of this multi-resistance plasmid among other environmental and clinical microorganisms.
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Affiliation(s)
- Kathia Lüneberg
- Laboratorio de Aerobiología, Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | - Eduardo Mucito-Varela
- Programa de Inmunología Molecular Microbiana, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Leticia Martínez
- Laboratorio de Aerobiología, Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Eva Salinas
- Laboratorio de Aerobiología, Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Yolanda López-Vidal
- Programa de Inmunología Molecular Microbiana, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Christina Siebe
- Departamento de Ciencias Ambientales y del Suelo, Instituto de Geología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Irma Rosas
- Laboratorio de Aerobiología, Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico
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