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Journal of Environmental and Public Health
Volume 2017, Article ID 3931802, 13 pages
Research Article

Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi

1College of Medicine, University of Malawi, P/Bag 360, Chichiri, Blantyre 3, Malawi
2The Polytechnic, University of Malawi, P/Bag 303, Chichiri, Blantyre 3, Malawi
3Sanitation and Hygiene Applied Research for Equity (SHARE), London School of Hygiene and Tropical Medicine, London, UK
4Lilongwe University of Agriculture and Natural Resources, P.O. Box 219, Lilongwe, Malawi
5Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, UK

Correspondence should be addressed to Save Kumwenda;

Received 8 May 2017; Revised 28 August 2017; Accepted 1 October 2017; Published 8 November 2017

Academic Editor: Linda M. Gerber

Copyright © 2017 Save Kumwenda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Use of Ecological Sanitation (EcoSan) sludge is becoming popular due to increasing price of organic fertilizers in Malawi; however, there is little evidence on the associated risks. Quantitative microbiological risk assessment (QMRA) was done to determine health risks associated with use of EcoSan. Pathogens considered included Escherichia coli (E. coli), Salmonella, and soil transmitted helminths (STHs). Exponential and Beta Poisson models were used to estimate the risk from helminthic and bacterial pathogens, respectively. Main exposure pathways were through poor storage of sludge, contamination of foods during drying, walking barefoot on the ground contaminated with sludge, pit emptying without protection, and application of sludge in the fields. Estimated annual risk for Ascaris lumbricoides, Taenia, and hookworms was approximately over 5.6 × 10−1 for both Fossa Alternas (FAs) and Urine Diverting Dry Toilet (UDDTs). Risk from E. coli and Salmonella was 8.9 × 10−2 and above. The risks were higher than WHO acceptable risk for use of faecal sludge in crops of 10−4 infections per year. Promoters and users of EcoSan latrines need to consider advocating for strict guidelines to reduce the risk.