title: Limited effectiveness of household sand filters for removal of arsenic from well water in North Vietnam.
abstract: Since well water utilized for domestic purposes in the Red River Delta of North Vietnam has been reported to be polluted by arsenic, barium, iron, and manganese, household sand filters consisting of various components are used. Information regarding the effectiveness of various sand filters for removal of the four toxic elements in well water is limited. In this study, arsenic levels in 13/20 of well water samples and 1/7 of tap water samples exceeded World Health Organization (WHO) health-based guideline value for drinking water. Moreover, 2/20, 6/20, and 4/20 of well water samples had levels exceeding the present and previous guideline levels for barium, iron, and manganese, respectively. Levels of iron and manganese, but not arsenic, in well water treated by sand filters were lower than those in untreated water, although previous studies showed that sand filters removed all of those elements from water. A low ratio of iron/arsenic in well water may not be sufficient for efficient removal of arsenic from household sand filters. The levels of barium in well water treated by sand filters, especially a filter composed of sand and charcoal, were significantly lower than those in untreated water. Thus, we demonstrated characteristics of sand filters in North Vietnam.
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan; Department of Pharmacology, Faculty of Medicine Andalas University, Padang, West Sumatra, Indonesia.
authors.forename: Cimi
authors.initials: C
authors.lastname: Ilmiawati
authors.affiliation: Units of Environmental Health Sciences, Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, Japan; University of Science, Vietnam National University, Hanoi, Vietnam.
authors.forename: Nguyen Dinh
authors.initials: ND
authors.lastname: Thang
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Units of Environmental Health Sciences, Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Iida
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Maeda
authors.affiliation: Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Ohnuma
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Units of Environmental Health Sciences, Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yajima
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Units of Environmental Health Sciences, Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Ohgami
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Reina
authors.initials: R
authors.lastname: Oshino
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: M M Aeorangajeb
authors.initials: MM
authors.lastname: Al Hossain
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ninomiya
authors.affiliation: Departments of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan E-mail: katomasa@med.nagoya-u.ac.jp; Units of Environmental Health Sciences, Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, Japan; Voluntary Body for International Healthcare in Universities, Nagoya, Aichi 466-8550, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kato
mesh_terms: D001151:Arsenic / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis*; D004784:Environmental Monitoring; D005374:Filtration / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry*; D014744:Vietnam; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D001151:Arsenic