Wastewater-Irrigated Urban Agriculture in the Context of WASH in Ahmedabad, India

Urbanization is characterized by the densification and spatial expansion of urban agglomerations, leading to its encroachment into agricultural land. In light of population growth, the growing food requirements of an increasingly larger population depend on decreasing agricultural land resources. Urban agriculture has emerged as a strategy to convert these challenges into opportunities. Instead of displacing agricultural production, agricultural activities are integrated into the urban system, producing food in close proximity to its place of consumption. In addition, urban agriculture is a low-input system, where the inputs of production are drawn from the urban waste-stream. The use of wastewater not only provides perennial irrigation water but also reduces the need for artificial fertilizers. Yet the unplanned reuse of wastewater poses health risks to both the farmers and consumers, as wastewater hosts a multitude of pathogens, chemicals and pharmaceutical residues. This study assessed the diarrheal disease risk of wastewater irrigation in the urban agriculture context of Ahmedabad, India, and compared the disease risk with the established diarrhea determinants: WASH (Water, Sanitation and Hygiene). The exposed population experience 13.3 diarrhea episodes per 1,000 person-weeks, while the incidence rate among the control group reached 7.9 episodes per 1,000 person-weeks. Mitigating the health risks of wastewater irrigation needs to be part of diarrhea prevention strategies, as pathogens are introduced into the farm environment and transferred to the community, potentially undermining the efforts of WASH interventions.