Managing Microbial Risks from Indirect Wastewater Reuse for Irrigation in Urbanizing Watersheds
Digital Object Identifier (DOI)
Limited supply of clean water in urbanizing watersheds creates challenges for safely sustaining irrigated agriculture and global food security. On-farm interventions, such as riverbank filtration (RBF), are used in developing countries to treat irrigation water from rivers with extensive fecal contamination. Using a Bayesian approach incorporating ethnographic data and pathogen measurements, quantitative microbial risk assessment (QMRA) methods were employed to assess the impact of RBF on consumer health burdens for Giardia, Cryptosporidium, rotavirus, norovirus, and adenovirus infections resulting from indirect wastewater reuse, with lettuce irrigation in Bolivia as a model system. Concentrations of the microbial source tracking markers pepper mild mottle virus and HF183 Bacteroides were respectively 2.9 and 5.5 log10 units lower in RBF-treated water than in the river water. Consumption of lettuce irrigated with river water caused an estimated median health burden that represents 37% of Bolivia’s overall diarrheal disease burden, but RBF resulted in an estimated health burden that is only 1.1% of this overall diarrheal disease burden. Variability and uncertainty associated with environmental and cultural factors affecting exposure correlated more with QMRA-predicted health outcomes than factors related to disease vulnerability. Policies governing simple on-farm interventions like RBF can be intermediary solutions for communities in urbanizing watersheds that currently lack wastewater treatment.
Was this content written or created while at USF?
Citation / Publisher Attribution
Environmental Science and Technology, v. 50, issue 13, p. 6803-6813
Scholar Commons Citation
Verbyla, Matthew; Symonds, Erin; Kafle, Ram; Cairns, Maryann; Iriarte, Mercedes; Guzmán, Alvaro Mercado; Coronado, Olver; Breitbart, Mya; Ledo, Carmen; and Mihelcic, James, "Managing Microbial Risks from Indirect Wastewater Reuse for Irrigation in Urbanizing Watersheds" (2016). Marine Science Faculty Publications. 702.