Addressing Livestock-derived Antimicrobial pollution in the Nairobi River in Kenya

联合国估计，全球使用的抗生素中有70%最终用于牲畜（UN, 2017）。为了跟上全球对动物产品的需求，预计到2030年，这一使用量将增长65%以上（同上）。这些数字对世界水道有着严重的影响。在与抗菌素耐药性有关的全球危机中，许多注意力集中在管理工作上。直到最近，人们才认识到这一问题中环境因素的影响程度。新兴研究表明，世界上许多河流除了耐药细菌外，还受到抗生素残留和抗生素耐药基因（ARGs）的严重污染。商业和自给农业系统的径流和污水被认为是ARGs和抗生素残留物的主要来源。我们还知道，重金属等其他污染物往往会加速抗菌素耐药性的产生，而重金属同样是某些农业系统的副产品。目前，肯尼亚的内罗毕河已跻身全球十大药物污染水道之列。为确定6种不同抗生素的存在而进行的测试显示，频率在60%至97.5%之间。此外，还检测到环丙沙星、四环素和恩诺沙星等兽用抗生素含量偏高。然而，内罗毕河流域也是400多万居民的家园，其中许多人生活在非正式住区，他们的生命和生计受到这些有毒物质的直接威胁。为了应对这一问题，本项目将利用以下六个相关研究项目的研究结果：1。“支持循证政策：印度和肯尼亚畜牧业社区抗菌素耐药性风险行为的纵向研究（SEP-AMR）”（ES/P00492X/2）；PI：克莱尔·赫弗南教授。该项目探讨了肯尼亚和印度自给农业社区抗菌素耐药性上升的社会、行为和环境驱动因素。“通过增强集体抵御力（AMFORA）来控制全球水生动物食品系统中的抗菌素耐药性”（MR/R015104/1； PI: Javier Guitian教授，RVC）。AMFORA项目采用系统思维方法绘制越南水产养殖系统地图，以确定出现和选择抗性的热点。3.“斯里兰卡环境中人类暴露于抗菌药物耐药性的驱动因素”。（MR/R014876/1； PI: Alistair Boxall教授）。该项目制定了一个空间框架，用于模拟斯里兰卡环境中抗菌物质和抗生素耐药基因的发生情况。4. “全球药品监测项目”，该项目对72个国家的165条河流进行了药物检测。在肯尼亚，超过50%的样本中发现抗生素残留，在内罗毕河的支流中发现的浓度最高。“低成本环保纳米材料和太阳能热装置用于经济实惠的清洁水生产”（城市大学GCRF机构奖），主持：吴卫平博士。该项目开发了改善水质和监测污染的新工具。6. “孟加拉的安全环境与人类生活：制造低成本滤水器净化工业污水”（GCRF机构奖给城市大学），项目负责人：Sumsun Naher博士和Ken Grattan教授。该项目使用香蕉叶生产低成本的滤水器。我们的项目将与从当地社区到政策制定者的一系列利益攸关方合作，确定/绘制与牲畜有关的污水来源。我们将测试三种低成本水过滤器筛选抗生素残留、细菌和重金属的可行性、稳健性和可持续性。我们会举办一系列与公众，包括学童参与的活动。通过这种方式，我们将利用一个跨学科的研究平台，向这个紧迫问题的“解决方案空间”迈进。

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.