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

全球问题：在陆地、淡水和海洋生态系统中，大量塑料的存在似乎几乎无处不在，经常有关于塑料对生态系统健康产生负面影响的报道。这导致联合国环境规划署将塑料污染列为全球十大环境问题之一。塑料污染问题在低收入和中等收入国家尤为严重，它正在损害世界上数十亿最贫穷和最脆弱人群的健康和福祉。此外，它还损害了我们实现联合国许多可持续发展目标(SDG)的能力。虽然已经花费了大量的研究努力来了解微塑料在海洋系统中的行为，但塑料在陆地环境中的影响，特别是对农业系统的影响，仍然知之甚少。考虑到到达海洋的80%的塑料是在陆地上生产、使用并经常被丢弃的，这令人惊讶。这也引发了人们的猜测，即在陆地系统中，微塑料实际上可能是最令人担忧的。LMIC中的塑料悖论：在过去的50年里，许多政府和海外援助机构积极鼓励在农业中使用塑料，以促进更高的资源利用效率和粮食安全。特别是塑料地膜的采用，改变了世界各地数百万小农的生计，然而，这是以巨大的环境成本为代价的。从田里移走塑料的困难，对其对农业生态系统健康的影响缺乏认识，以及有效处置塑料的社会经济/实际障碍，留下了将持续许多代人的塑料污染遗产。因此，迫切需要对这些遗留塑料构成的环境和人类健康风险进行批判性评估，并设计有效的方法和社会结构来防止进一步积累，并尝试修复塑料污染领域。解决问题：为了解决问题并帮助提供切实的解决方案，我们召集了来自5个不同国家(中国、埃及、印度、斯里兰卡和越南)的自然和社会科学家组成的多学科团队。我们选择这5个国家是因为这是农业塑料污染问题最严重的地方，因为它们正处于解决该问题的不同阶段。这些国家每年总共使用300万吨农业塑料薄膜，覆盖2500万公顷农田。它们还跨越广泛的气候，并拥有一系列治理结构，这将使我们的成果能够很容易地转化为其他类似的小岛屿发展中国家。因此，我们研究的总体目标是量化传统宏观、微型和纳米塑料对农业生态系统长期健康构成的风险。这些信息将被用来批判性地评估传统农业塑料使用对粮食安全和农村生计可能产生的影响。此外，我们的目标是找到切实可行、经济上、社会上可以接受和政治上可行的解决方案，以帮助修复受塑料污染的土地，并通过持久的行为和政策变化防止进一步的污染发生。项目遗产：我们的基本方法将是共同设计针对具体情况的、当地拥有的干预措施，以减少塑料遗产，同时仍保持可持续的耕作做法和生计。至关重要的是，我们要创造遗产，以确保我们开发的工具、技术、知识和伙伴关系在项目结束日期之后仍然存在，并确保成果继续传播到其他小岛屿发展中国家。我们已经将遗产嵌入到我们的项目结构中。例如，我们将提高LMIC研究人员的技能，建立研究资本，创建信息门户，并设计新的决策支持工具。

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.