Burden of Diarrheal Diseases from Biogas Wastewater Exposure
Among Smallholder Farmers in Ha Nam Province, Vietnam
Phuc Pham-Duc; Toan Luu-Quoc; Huong Nguyen-Mai; Tuyet-Hanh Tran Thi; Tung Dinh-Xuan; Hang Tran-Minh;
Hung Nguyen-Viet
Center for Public Health & Ecosystem Research, Hanoi University of Public Health; National Institute of Animal Scienc-
es; Institute of Anthropology; Vietnam Academy of Social Sciences; International Livestock Research Institute
INTRODUCTION
Livestock production has developed rapidly in Vietnam in recent years, particu-
larly at the small-scale which account for 65% of the total livestock production.
Biogas systems are commonly used to treat livestock waste, however, the
health risks from biogas wastewater exposure at smallholder farms are not yet
well understood. Objective was applied transdisciplinary and community par-
ticipatory approach (called Ecohealth approach) to assess the health risks as-
sociated with biogas wastewater; and improve knowledge and practice of
farmer for better operation of biogas systems and treatment of waste.
Contact: Phuc Pham-Duc
Email: pdp@vohun.org ; pdp@huph.edu.vn
Mobile: (+84) 904049969. Web: www.vohun.org
METHODS
Research Process
A quantitative microbial risk assessment approach was applied to estimate the
burden of diarrheal diseases from biogas wastewater exposure among 451
smallholder farmers using biogas systems in Ha Nam province. A total of 150
biogas wastewater samples were collected and analysed for E. coli, Giardia,
and Cryptosporidium.
CONCLUSION
The results suggest the importance in reducing concentrations of pathogens
in biogas wastewater before use in the fields as a means for mitigating pub-
lic health impacts.
The study showed that farmers faced diarrheal disease risks due to expo-
sure to biogas wastewater at different exposure scenarios. The calculated
annual risk of diarrheal disease by E. coli ranked from 0.15 to 0.21; by Giar-
dia ranked from 0.022 to 0.095; and by Cryptosporidium ranked from 0.006
to 0.015. The estimated diarrheal diseases burden from pathogens in all ex-
posure scenarios largely exceeded the reference level of health outcome
target of 10-6
DALYs loss per person per year recommended by WHO.
RESULTS
ACKNOWLEDGEMENTS
This study was supported by the Canadian International Development Research
Center (IDRC) through the project of Ecohealth Field Building Leadership Initiative
(FBLI) in Southeast Asia.
This poster presentation and travel award are made possible by the generous sup-
port of the American people through the United States Agency for International
Development (USAID). The contents are the responsibility of the presenters and
do not necessarily reflect the views of USAID or the United States Government.
Current status of agriculture & environment in Ha Nam
Pathogens in biogas wastewater at the small-holder farms
Figure 1: The burden of diarrhoeal from pathogens in all the expo-
sure scenarios
Pathogens Positive Mean ± SD QCVN 62-
MT:2016/
BTNMTn %
E. coli (*)
(CFU/ml) 75 100 14,665 ± 34,854 5,000
Giardia(**)
(cysts/ml) 33 44.0 9.4 ± 23.0 -
Cryptosporidium(**)
(cysts/ml)
26 34.7 9.2 ± 25.7 -