title: H2S as an indicator of water supply vulnerability and health risk in low-resource settings: a prospective cohort study.
abstract: In this large-scale longitudinal study conducted in rural Southern India, we compared a presence/absence hydrogen sulfide (H2S) test with quantitative assays for total coliforms and Escherichia coli as measures of water quality, health risk, and water supply vulnerability to microbial contamination. None of the three indicators showed a significant association with child diarrhea. The presence of H2S in a water sample was associated with higher levels of total coliform species that may have included E. coli but that were not restricted to E. coli. In addition, we observed a strong relationship between the percent positive H2S test results and total coliform levels among water source samples (R(2) = 0.87). The consistent relationships between H2S and total coliform levels indicate that presence/absence of H2S tests provide a cost-effective option for assessing both the vulnerability of water supplies to microbial contamination and the results of water quality management and risk mitigation efforts.
authors.affiliation: The Aquaya Institute, San Francisco, California 94129, USA. ranjiv@aquaya.org
authors.forename: Ranjiv S
authors.initials: RS
authors.lastname: Khush
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Arnold
authors.forename: Padma
authors.initials: P
authors.lastname: Srikanth
authors.forename: Suchithra
authors.initials: S
authors.lastname: Sudharsanam
authors.forename: Padmavathi
authors.initials: P
authors.lastname: Ramaswamy
authors.forename: Natesan
authors.initials: N
authors.lastname: Durairaj
authors.forename: Alicia G
authors.initials: AG
authors.lastname: London
authors.forename: Prabhakar
authors.initials: P
authors.lastname: Ramaprabha
authors.forename: Paramasivan
authors.initials: P
authors.lastname: Rajkumar
authors.forename: Kalpana
authors.initials: K
authors.lastname: Balakrishnan
authors.forename: John M
authors.initials: JM
authors.lastname: Colford
mesh_terms: D002675:Child, Preschool; D015331:Cohort Studies; D003967:Diarrhea / Q000453:epidemiology* / Q000209:etiology; D004755:Enterobacteriaceae / Q000502:physiology*; D005260:Female; D006801:Humans; D006862:Hydrogen Sulfide / Q000737:chemistry*; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population; D012959:Socioeconomic Factors; D014867:Water / Q000737:chemistry*; D014871:Water Microbiology / Q000592:standards*; D014881:Water Supply / Q000592:standards*
chemical_list: D014867:Water; D006862:Hydrogen Sulfide