Integrating the safe and sustainable management of wastewater into small-scale vegetable production systems in Malawi

We are seeking a highly motivated individual to carry out PhD research in the fields of environmental health and sustainable development. This prestigious IAPETUS studentship, funded by the Natural Environment Research Council (NERC), will provide a platform to build an interdisciplinary research career in the integrated fields of public health and the environmental sciences.

The successful candidate will be based at the University of Stirling, supervised by Professor Richard Quilliam and Professor Kate Hampshire (Durham University), Dr Heather Price & Dr David Oliver, with additional supervision from Dr Tracy Morse (WASHTED, Malawi Polytechnic). The student will also become fully embedded within the “Environmental Sustainability & Human Health Research Group” https://eshh-stirling.com/ at the University of Stirling.

Background
Worldwide, more than 800 million farmers are engaged in urban agriculture. Of these, about 200 million practice market-oriented farming, and often have no other choice but to use wastewater for irrigation [in this proposal we refer to ‘wastewater’ as the use of raw, partly treated, or diluted wastewater, from predominantly domestic sources]. Urban and peri-urban farmers in the developing world can enhance household income by producing perishable crops such as leafy vegetables for sale in local markets. These farmers are crucial for providing a continual supply of vitamin-rich vegetables to the community, and it is estimated that urban farmers who irrigate their crops with wastewater supply about 60% of vegetables sold in African cities. Such production of fresh vegetables is fundamental for alleviating hidden hunger (the deficiency in micronutrients, vitamins and minerals in the diet); furthermore, urban farming can provide significant employment and economic opportunities. Farmers often prefer to use wastewater for irrigation as it provides a free source of nitrogen and phosphorus (and thus, less money spent on fertilisers), and can be more reliable or cheaper than other water sources. Effluent is often in large supply, and compared to groundwater in Malawi, is low in salinity and high in nitrogen. Consequently, it has now become common practice in Malawi for urban farmers to deliberately vandalise wastewater flow channels or drain covers to divert effluent into their vegetable gardens. However, sanitary wastewater contains a variety of human pathogens, such as viruses, bacteria, parasites and helminths (many of which are capable of survival in the environment long enough to be transmitted to humans), together with a risk from anti-microbial resistance (AMR) genes. Thus, farmers are exposed to relatively high concentrations of pathogens, and have an increased risk of enteric disease and infections with worms. Women, who provide much of the labour required to produce vegetables are particularly at risk; women also dominate in the marketing and retail process and are mainly responsible for preparing family meals, which creates the opportunity for transferring pathogens to family members and the wider community. The sale of contaminated vegetables and leafy greens in markets is therefore of significant public health concern and despite international guidelines for using wastewater in agriculture, this knowledge is poorly implemented at the local governmental level, and guidelines are rarely translated to local farmers.

Methodology:
Integrating the safe and sustainable management of wastewater with increased agricultural productivity has recently gained interest in many countries. Therefore, the overarching objective of this studentship is to involve local water management stakeholders, urban water users and agricultural wastewater user groups to provide an interdisciplinary framework for the student to integrate policy, health, environmental and engineering dimensions that cuts across traditional academic disciplines. Specifically, the research objectives of this project are to:
1. Create a ‘Stakeholder’s Alliance’ to provide an intersectoral forum to identify and integrate farmer’s and public health leader’s needs and concerns, while addressing food security and public health risks to people and the wider community
2. Map areas of wastewater irrigation within the Blantyre municipal area, and monitor the dynamics of water quality and subsequent contamination of vegetables at four case-study sites
3. Develop and test context-specific interventions (including assessment of the associated trade-offs) for reducing pathogen transfer from wastewater irrigation to vegetables and leafy greens
4. Trial innovative public awareness programmes to inform farmers and consumers of the potential health impacts of wastewater irrigation, and key targets for improved practice
5. Develop a ‘National Policy Framework’ to facilitate the safe use of wastewater in food production