The UN estimates that 70% of the antibiotics used globally end up in livestock (UN, 2017). And to keep up with the global demand for animal products, this use is predicted to rise by over 65% by 2030 (ibid). The figures have grave implications for the world's waterways. In the global crisis relating to antimicrobial resistance much attention has centred on stewardship. Only recently has the extent of the environmental component of the problem been recognised. Emerging research has demonstrated that many of the world's rivers are highly contaminated with antibiotic residues and antibiotic resistance genes (ARGs) in addition to resistant bacteria. Run-off and effluent from commercial and subsistence farming systems have been implicated as key sources of ARGs and antibiotic residues. We also know that antimicrobial resistance is often accelerated by other pollutants such as heavy metals, which equally are a by-product of some farming systems.

At present, the Nairobi river in Kenya has been ranked among the top ten global waterways in terms of pharmaceutical contamination. Tests undertaken to determine the presence of 6 different antibiotics revealed frequencies between 60 and 97.5%. High levels of the veterinary antibiotics such as ciprofloxacin, tetracycline and enrofloxacin have also been detected. Yet the Nairobi river basin is also home to over 4 million inhabitants, many living in informal settlements, whose lives and livelihoods are at direct risk from these toxicities. To respond to this issue, this project will leverage the findings of the following six, related research projects:

1. 'Supporting Evidence-Based Policy: a longitudinal study of AMR risk behaviours among livestock keeping communities in India and Kenya (SEP-AMR)' (ES/P00492X/2); PI: Prof Claire Heffernan. The project explored social, behavioural and environmental drivers forging the rise in antimicrobial resistance among subsistence farming communities in Kenya and India.
2. 'Towards controlling antimicrobial resistance in global aquatic animal food systems by enhancing collective resilience (AMFORA)' (MR/R015104/1; PI: Prof Javier Guitian, RVC).The AMFORA project used a systems-thinking approach to map aquaculture systems in Vietnam in order to identify hotspots for emergence and selection of resistance.
3.'Drivers of human exposure to antibacterial resistance in the Sri Lankan environment'. (MR/R014876/1; PI: Prof Alistair Boxall). The project developed a spatial framework for modelling the occurrence of antibacterial substances and antibiotic resistance genes in the environment of Sri-Lanka.
4. 'Global Monitoring of Pharmaceuticals Project', which tested 165 rivers in 72 countries for pharmaceuticals. In Kenya, antibiotic residues were found in over 50% of the samples, the highest concentrations were found in tributaries of the Nairobi river.
5. 'Low cost environmentally friendly nanomaterials and solar thermal devices for affordable clean water production' (GCRF Institutional Award to City University), PI: Dr Weiping Wu. This project developed new tools for water quality improvement and pollution monitoring.
6. 'Safe environment and human life in Bangladesh: a low-cost water filter fabrication to purify industrial polluted water' (GCRF Institutional Award to City University), PI: Dr Sumsun Naher and Professor Ken Grattan. The project produced low cost water filters using banana leaves.

Our project will work with a range of stakeholders from local communities to policy makers to identify/map sources of livestock-related effluents. We will test the feasibility, robustness and sustainability of three types of low-cost water filters to screen antibiotic residues, bacteria and heavy metals. We will undertake a range of engagement activities with the public, including school children. In this manner, we will utilise an interdisciplinary research platform to move towards the 'solutions space' to this pressing problem.

Potential Impact:
Our project will directly benefit the following groups:

1. Residents of informal settlements;
2. Subsistence livestock keepers/small-scale fish farmers dependent on the Nairobi river as a water source;
3. Commercial livestock producers;
4. Policy makers and planners (at both the national and global levels);
5. Nairobi City officials;
6. Teachers and students residing in the informal settlements of Nairobi;
7. Local and international academics working across the fields of AMR, environmental pollution, river ecology, animal health, veterinary medicine, aquaculture, urban and global development, engineering, water filters and sensors;
8. UN agencies and other multi-lateral agencies working across the AMR, environmental pollution and safe-water space.

Residents of informal settlements are both polluters of the Nairobi river and ultimately consumers of its water. Livestock farming within these settlements is a common livelihood activity, particularly for women, and ranges from small-scale aquaculture to pig and poultry production. These animals routinely consume untreated water. Equally problematic, waste and waste water from these activities are commonly used for peri-urban crop activities or dumped into waterways. Across our project we will work with in excess of 50 women's groups in these settlements to develop strategies for the safe elimination of livestock waste and to explore the application of filters at both the household and community levels. Our work aims to both develop awareness of environmental AMR, and directly decrease the hazards associated with producing and consuming heavily contaminated animal source foods. The direct benefits of our project for these communities relate to increases in public health via improvements to WASH and food security. Livelihood benefits are also likely to accrue as livestock health is improved. In this manner, we aim to improve the lives and livelihoods of some of the most marginalised communities on the planet.

We will work directly with large-scale commercial poultry producers located upstream to the Nairobi river both to raise awareness and to engage these producers in the use and application of our innovative filters. We will further work with officials at the National Environmental Management Authority (NEMA) in charge of monitoring effluent and waste from abattoirs and policing wastewater treatment standards for Nairobi. Both of these groups will directly benefit from the project outputs. We will engage teachers and schools across the Nairobi river basin in AMR and the environmental parameters of this crisis. We aim to reach over 200 schools in our outreach activities (out with the inception phase). We anticipate that critical benefits of such engagement include supporting awareness raising and increased community activism around this issue. Finally, at the global level, we will engage UNEP and other international multi-lateral agencies with both the progress and challenges of this project. In global development, large-scale clean water schemes have been plagued with technological and sustainability issues. By engaging the wider community in our innovative filters and equally, by clearly detailing issues with adaption, sustainability and community engagement we aim to identify, develop and support clear pathways to impact with partner organisations working at the global level.