Do agricultural microplastics undermine food security and sustainable development in developing countries?

THE GLOBAL PROBLEM: The presence of large amounts of plastic in terrestrial, freshwater and marine ecosystems appears almost ubiquitous, with frequent reports of negative impacts of plastics on ecosystem health. This has led to the United Nations Environment Programme declaring plastic pollution as one of the top 10 global environmental problems. The problem of plastic pollution is particularly acute in low and middle-income countries (LMICs) where it is impairing the health and wellbeing of billions of the world's poorest and most vulnerable people. In addition, it is compromising our ability to deliver many of the UN's Sustainable Development Goals (SDG). While much research effort has been spent understanding the behaviour of microplastics in marine systems, the impact of plastics in terrestrial environments, and especially agricultural systems, remains poorly understood. This is surprising considering that 80% of plastics arriving in the oceans were produced, used, and often disposed of on land. It has also led to speculation that it is within terrestrial systems that microplastics might actually be of greatest concern. THE PLASTIC PARADOX IN LMICs: Over the last 50 years, many governments and overseas aid agencies have actively encouraged the use of plastics within agriculture to promote greater resource use efficiency and food security. The adoption of plastic mulch films in particular, has transformed the livelihoods of millions of smallholder farmers across the world, however, this has been achieved at a large environmental cost. Difficulties in removing plastic from fields, a lack of appreciation for its impact on agroecosystem health, and socioeconomic/practical barriers to its effective disposal have left a plastic pollution legacy that will last for many generations to come. There is therefore an urgent need to critically evaluate the environmental and human health risks posed by these legacy plastics and to devise effective ways and social structures to prevent further accumulation and to try and remediate plastic contaminated fields. TACKLING THE ISSUE: To address the problem and help deliver tangible solutions, we have brought together a multidisciplinary team of natural and social scientists from 5 contrasting LMICs (China, Egypt, India, Sri Lanka and Vietnam). We chose these 5 countries as this is where the problem of agricultural plastic pollution is most acute and because they are at different stages of tackling the problem. Together, these countries use 3 million tonnes of agricultural plastic film each year covering 25 million hectares of agricultural land. They also span a wide range of climates and possess a range of governance structures which will enable our outcomes to be readily translated to other similar LMICs. Consequently, the overall aim of our research is to quantify the risk that conventional macro-, micro- and nano-plastics pose to the long-term health of agricultural ecosystems. This information will be used to critically evaluate the likely impact of conventional agricultural plastic use on food security and rural livelihoods. In addition, we aim to identify practical, economic, socially acceptable and politically viable solutions to help remediate land contaminated with plastic and prevent further pollution from occurring through lasting behaviour and policy change. PROJECT LEGACY: Our fundamental approach will be to co-design context-specific, locally-owned interventions to reduce the plastic legacy, while still maintaining sustainable farming practices and livelihoods. It is vital that we generate legacy to ensure that the tools, technology, knowledge and partnerships we develop persist well beyond the project end-date and that the outcomes continue to spread to other LMICs. We have embedded legacy into the fabric of our project. For example we will upskill LMIC researchers, build research capital, create an information portal and design novel decision support tools.