Wastewater use in crop production in peri-urban areas of Addis Ababa: impacts on health in farm households

Using stream water polluted with untreated wastewater in agriculture is controversial due to its combination of benefits and negative health impacts. Using data from a household survey, ‘wastewater’ and ‘freshwater’ farmers were analysed comparatively to examine the perceived impacts of irrigation water quality on farmers' health and to evaluate the extent of health damage. Probability of illness was estimated using the theory of utility-maximising behaviour of households subject to the conventional farm household production model, augmented by adding a health production function. Reduced model and instrumental variable probit specifications both show that perceived illness prevalence is significantly higher for household members working on wastewater irrigation farms than for those working with freshwater. Our data entails econometric complications (e.g., endogeneity of farmers' behaviour, unobserved location-specific characteristics). Ignoring these will result in underestimation of the value of policy interventions designed to reduce potential health damage of wastewater use in irrigation.