One liter of wastewater pollutes about eight liters of freshwater.

A holistic approach Untreated wastewater irrigation is not the only reason for the spread of pathogens. IWMI, therefore, also invests in more holistic multiple-hazard projects that analyze and compare risks from various sources and assess the cost-effectiveness of taking different actions. Ultimately, the aim is to advise authorities on how they can best prevent most people from dying or becoming sick at the lowest cost. One liter of wastewater pollutes about eight liters of freshwater. 1 Researchers at IWMI have been working on a variety of projects over more than a decade, which are aimed at assessing and reducing the risks associated with wastewater irrigation. They also explore social marketing tools to identify appropriate incentives that will trigger the behavioral changes needed to reduce the contamination of food produced with wastewater irrigation.
In collaboration with the World Health Organization (WHO), IWMI has been testing a ‘multi-barrier approach’to reducing the overall risk of pathogens in wastewater irrigation.2 Source: RR 141. Amoah et al., 2011. 3 The multi-barrier approach should be implemented with other health measures such as health education, hygiene promotion and the provision of access to safe drinking water and adequate sanitation.4
	“Our research does not end with IWMI recommending an effective risk-reducing practice; we also aim to identify the drivers and constraints that determine whether or not people will use them and, most importantly, change their habits.”
	Pay Drechsel - Theme Leader for Water Quality, Health and Environment (IWMI)
A recent hand washing campaign in Ghana exemplifies how lateral thinking is required when trying to bring about lasting behavioral changes. The campaign did not mention germs or bacteria, but simply drew on the ‘yuck factor’ that makes people feel uncomfortable when their hands, or other people’s hands, are dirty. Incentives for farmers can include more tangible benefits, such as credit access or improved land tenure.
1 http://assets.panda.org/downloads/worldwaterforumwaterfacts.pdf 2, 4 Bos, R.; Carr, R.; Keraita, Bernard. 2010. Assessing and mitigating wastewater-related health risks in low-income countries: An introduction. In Wastewater irrigation and health: Assessing and mitigating risk in low-income countries, ed. Drechsel, P.; Scott, C.A.; Raschid-Sally, L.; Redwood, M.; Bahri, A.. London, UK: Earthscan; Ottawa, Canada. International Development Research Centre (IDRC); Colombo, Sri Lanka: International Water Management Institute (IWMI), pp.29-47. 3 Amoah, Philip; Keraita, Bernard; Akple, Maxwell; Drechsel, Pay; Abaidoo, R. C.; Konradsen, F. 2011. Low-cost options for reducing consumer health risks from farm to fork where crops are irrigated with polluted water in West Africa. Colombo, Sri Lanka: International Water Management Institute (IWMI). 37p. (IWMI Research Report 141) source:www.who.int/foodsafety/publications/consumer/5keys/