Fate and Impacts of Microplastics and Nanoplastics in Terrestrial and Freshwater Environments

环境中到处都是塑料垃圾，全球越来越关注塑料垃圾对生物和生态系统的影响。尽管陆地上的微塑料和纳米塑料（MNP）污染很少受到关注，但据估计其污染程度远高于海洋。在加拿大土壤和淡水中纳米塑性转化、运输和毒性的控制过程方面，存在特别大的知识空白。因此，为了支持决策者制定适当的、知情的风险评估和管理战略，我们必须了解这些新出现的污染物在陆地和淡水环境中的命运和任何不利影响。***本研究方案的目标是评估导致向加拿大土壤和水域释放的MNP的命运和负担的过程，以及控制其影响的性质，以便为保护环境和公众健康的做法、政策和法规提供信息。在这个新兴领域提出的研究是原创和创新的，因为(i)它将提供关于纳米塑料的形成、环境命运和影响的新知识，这些知识由于方法上的挑战而大多被忽视；（ii）工程将在与北方气候和环境有关的条件下进行；（三）侧重于陆地和淡水环境中的塑料污染，与海洋系统相比，这些污染尤其被忽视。***本研究将由1名博士后（班廷研究员）、4名博士、3名硕士和5名本科生完成。本研究具有挑战性、创新性、涉及最先进的技术，并提供多学科合作的机会，具有很高的培训价值。用于解决我们的研究问题的方法将包括对MNP形成、聚集、运输和毒性的严格实验室研究。我们将首先通过模拟典型的加拿大冬季温度和冻融循环的影响来研究不同类型塑料的MNP形成率。对照试验的结果将与室外MNP暴露进行比较。我们还将量化加拿大淡水中具有代表性的一系列水化学物质的MNP运输。最后，将确定MNPs增强其他污染物运输的能力以及MNPs对昆虫的毒性。***这项研究将首次全面评估加拿大陆地和淡水生态系统中MNPs的命运和影响。所产生的原始科学知识肯定会改进风险评估并支持政府机构制定监管准则；即加拿大卫生部、加拿大环境与气候变化部和加拿大食品检验局。这项研究将通过出版物、会议、外联活动以及与政府和工业伙伴的持续伙伴关系进行传播。

Plastic litter is found everywhere in the environment and there is growing global concern about the impact it may have on organisms and ecosystems. Although microplastic and nanoplastic (MNP) contamination on land has received little attention, it is estimated to be much greater than in the ocean. There are particularly large knowledge gaps on the processes governing nanoplastic transformations, transport and toxicity in Canadian soils and freshwaters. Thus, to support policy makers in developing appropriate, informed strategies for risk assessment and management, it is important that we develop an understanding of the fate and any adverse impacts of these emerging pollutants in terrestrial and freshwater environments.***The objectives of this research program are to assess the processes driving the fate and burden of MNP released to Canadian soils and waters and the properties governing their impacts, towards informing practices, policies and regulations that will protect the environment and public health. The proposed research in this emerging field is original and innovative because (i) it will provide new knowledge on the formation, environmental fate and impacts of nanoplastics that have been mostly ignored due to methodological challenges; (ii) the work will be done under conditions relevant to a Northern climate and environment; and (iii) it focuses on plastic pollution in terrestrial and freshwater environments that have been particularly overlooked in comparison to marine systems.***The research will be accomplished by 1 postdoc (Banting fellow), 4 PhD, 3 Masters, and 5 undergraduate students. This research has very high training value as it is challenging, innovative, involves state-of-the-art techniques, and offers opportunities for multidisciplinary collaboration. The approach used to address our research questions will include rigorous laboratory studies of MNP formation, aggregation, transport and toxicity. We will first study MNP formation rates from different types of plastics by simulating the effects of typical Canadian winter temperatures and freeze-thaw cycles. Results from controlled tests will be compared to outdoor MNP exposures. We will also quantify MNP transport over a range of water chemistries representative of Canadian freshwaters. Finally, the ability of MNPs to enhance the transport of other contaminants and the toxicity of MNPs to insects will be determined.***This research will be the first to comprehensively evaluate the fate and impacts of MNPs in terrestrial and freshwater ecosystems in a Canadian context. The original scientific knowledge generated is sure to improve risk assessments and support the development of regulatory guidelines by government agencies; namely, Health Canada, Environment and Climate Change Canada and the Canadian Food Inspection Agency. The research will be disseminated through publications, conferences, outreach activities and ongoing partnerships with government and industrial partners.