title: Provision of well-water treatment units to 600 households in Bangladesh: A longitudinal analysis of urinary arsenic indicates fading utility.
abstract: BACKGROUND
  Millions of villagers in Bangladesh remain exposed to high levels of arsenic (As) from drinking untreated well-water even though the scale of the problem was recognized 15years ago. Water treatment at the household-level has been promoted as a viable complement but few longitudinal studies of their efficacy using an objective measure of exposure have been conducted. Participants (N=622) of a nutrition trial in Araihazar, Bangladesh were each provided with READ-F filters at the beginning of the study and encouraged to use them over the 6month duration of the intervention. Well-water As, treated water As, and urinary As were monitored periodically during the trial and measured again one year after the trial ended.
  
  
  RESULTS
  The READ-F filters were initially well received and median urinary As levels for participants declined from 117μg/L to 51μg/L within a single week. However, median urinary As levels gradually rose back to 126μg/L by the end of the trial. Fifty filters were replaced over the course of the trial because of insufficient As removal or reduced flow. With these exceptions, most of the treated water met the WHO guideline for As in drinking water of 10μg/L. One year after the nutritional trial ended, 95% of participants had abandoned their filter citing inconvenience as the primary reason. At that time, median urinary As levels for 10 participants who had switched to a nearby low-As well had declined to 63μg/L.
  
  
  CONCLUSIONS
  Participants were probably no longer using the READ-F filter long before the 6month nutritional intervention ended despite claiming that they were using them. Household-level treatment is likely to continue to play a minor role in the effort to reduce As exposure in Bangladesh. Understanding the limitations of such expensive interventions is important for future policy regarding As mitigation.
authors.affiliation: Department of Environmental Health Sciences, Columbia University, 722 West 168th St. Floor 11, New York, NY 10032, United States. Electronic address: trs2111@cumc.columbia.edu.
authors.forename: Tiffany R
authors.initials: TR
authors.lastname: Sanchez
authors.affiliation: Department of Biostatistics, Columbia University, 722 West 168th St. Floor 8, New York, NY 10032, United States. Electronic address: dl2015@cumc.columbia.edu.
authors.forename: Diane
authors.initials: D
authors.lastname: Levy
authors.affiliation: Columbia University Bangladesh Research Project, Dhaka, Bangladesh. Electronic address: shahriar@urb-bd.org.
authors.forename: Mohammad Hasan
authors.initials: MH
authors.lastname: Shahriar
authors.affiliation: Columbia University Bangladesh Research Project, Dhaka, Bangladesh. Electronic address: nasirbmb@gmail.com.
authors.forename: Mohammad Nasir
authors.initials: MN
authors.lastname: Uddin
authors.affiliation: Columbia University Bangladesh Research Project, Dhaka, Bangladesh. Electronic address: suman_siddiq@yahoo.com.
authors.forename: Abu B
authors.initials: AB
authors.lastname: Siddique
authors.affiliation: Department of Environmental Health Sciences, Columbia University, 722 West 168th St. Floor 11, New York, NY 10032, United States. Electronic address: jg24@cumc.columbia.edu.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Graziano
authors.affiliation: Department of Environmental Health Sciences, Columbia University, 722 West 168th St. Floor 11, New York, NY 10032, United States. Electronic address: aml2221@cumc.columbia.edu.
authors.forename: Angela
authors.initials: A
authors.lastname: Lomax-Luu
authors.affiliation: Department of Geochemistry, Lamont-Doherty Earth Observatory, 131 Comer. 61 Route 9W, PO Box 1000, Palisades, NY 10964, United States. Electronic address: avangeen@ldeo.columbia.edu.
authors.forename: Alexander
authors.initials: A
authors.lastname: van Geen
authors.affiliation: Department of Environmental Health Sciences, Columbia University, 722 West 168th St. Floor 11, New York, NY 10032, United States. Electronic address: mvg7@cumc.columbia.edu.
authors.forename: Mary V
authors.initials: MV
authors.lastname: Gamble
mesh_terms: D000328:Adult; D001151:Arsenic / Q000032:analysis / Q000652:urine*; D001459:Bangladesh; D060766:Drinking Water / Q000032:analysis*; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000652:urine*; D018508:Water Purification / Q000191:economics / Q000379:methods*; D014881:Water Supply; D055815:Young Adult
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Arsenic; Biomarker; Groundwater; Longitudinal study; Treatment; Water filters