title: Diarrhea risks by exposure to livestock waste in Vietnam using quantitative microbial risk assessment.
abstract: OBJECTIVE
  The aim of this paper was to assess the diarrhea risks caused by various pathogens among those exposed to biogas wastewater through different activities.
  
  
  METHODS
  Application of quantitative microbial risk assessment (QMRA) of biogas wastewater was conducted in Hanam Province, Vietnam. A total of 451 representatives from households that use biogas were interviewed about their practices of handling biogas plant and reuse of biogas effluent for irrigation. In addition, 150 samples of biogas wastewater were analyzed for Escherichia coli, Cryptosporidium parvum, and Giardia lamblia. Risk characterization was calculated using Monte Carlo simulation.
  
  
  RESULTS
  The annual diarrhea risk caused by exposure to biogas effluent through irrigation activities ranged from 17.4 to 21.1% (E. coli O157:H7), 1.0 to 2.3% (G. lamblia), and 0.2 to 0.5% (C. parvum), while those caused through unblocking drains connected to biogas effluent tanks were 22.0% (E. coli), 0.7% (G. lamblia), and 0.5% (C. parvum).
  
  
  CONCLUSIONS
  Further measures are needed to reduce the risk by either improving the microbial quality of biogas effluent or by ensuring the use of personal protective measures when exposed to biogas wastewater.
authors.affiliation: Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam.
authors.forename: Thu
authors.initials: T
authors.lastname: Le-Thi
authors.affiliation: Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam.
authors.forename: Phuc
authors.initials: P
authors.lastname: Pham-Duc
authors.affiliation: Department of Water and Sanitation in Developing Countries, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Zurbrügg
authors.affiliation: Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam.
authors.forename: Toan
authors.initials: T
authors.lastname: Luu-Quoc
authors.affiliation: Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam.
authors.forename: Huong
authors.initials: H
authors.lastname: Nguyen-Mai
authors.affiliation: Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam.
authors.forename: Tu
authors.initials: T
authors.lastname: Vu-Van
authors.affiliation: Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam. h.nguyen@cgiar.org.|International Livestock Research Institute, Van Phuc Diplomatic Compound, 298 Kim Ma Street, Ba Dinh District, Hanoi, Vietnam. h.nguyen@cgiar.org.
authors.forename: Hung
authors.initials: H
authors.lastname: Nguyen-Viet
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D000818:Animals; D056804:Biofuels; D016785:Cryptosporidium parvum / Q000302:isolation & purification; D003967:Diarrhea / Q000453:epidemiology*; D004781:Environmental Exposure / Q000032:analysis; D004926:Escherichia coli / Q000302:isolation & purification; D000067565:Farmers; D016829:Giardia lamblia / Q000302:isolation & purification; D006801:Humans; D058751:Livestock; D018570:Risk Assessment; D062065:Wastewater / Q000382:microbiology* / Q000469:parasitology*; D014871:Water Microbiology
chemical_list: D056804:Biofuels; D062065:Wastewater
keywords: Biogas effluent; Diarrhea; Exposure; Livestock waste; QMRA; Vietnam; Wastewater