Integrating impacts from marine plastics in Life Cycle Assessment

海洋垃圾，即塑料，是一个日益严重的环境问题，环境决策者正开始采取行动/实施旨在减少塑料使用和废物管理不善的法规。加拿大政府已经宣布，将在欧盟委员会的带头下，最早在2021年禁止有害的一次性塑料。加拿大的声明还明确指出，采取的措施将“基于科学证据”，这意味着需要证据表明，从环境角度来看，这种禁令和新的解决方案是一种改善，以支持这些决定。 生命周期评估(LCA)是一种支持环境决策的工具，专门设计用于确定产品替代品之间的潜在权衡，例如一次性使用的塑料杯和纸杯。然而，虽然生命周期评估被广泛用于支持决策，但目前还没有在生命周期评估中评估海洋垃圾，包括塑料的影响的方法。这可能会限制LCA作为一种工具的应用，在评估塑料禁令或创新解决方案等决定时，用于突出影响类别之间的潜在权衡。 这项研究的目的是开发不同的影响途径机制，以便提出表征模型和因素，以便将塑料在海洋环境中产生的影响纳入生命周期评估框架和方法。该计划包括的不同研究轴线集中在释放到水和海洋环境中的微塑料及其完整的影响路径模拟：1)从塑料进入不同环境舱和子舱的命运，2)物种对颗粒的暴露，以及3)这种塑料暴露对生命周期评价中生态系统质量损害类别的影响。此外，还量化了促成这一影响途径的大型塑料垃圾到微型塑料的降解。 因此，该计划将允许在生命周期评估中考虑塑料产品在管理良好的废物系统之外报废时的潜在影响。这些信息将为考虑不同替代方案(例如，产品或包装)的决策者提供信息，以比较每种替代方案的潜在影响和好处，而不会被所察觉的问题或不包括此类影响的结果所误导。通过将这些潜在的损害纳入LCA模型，撞击位移--例如选择一种可能增加全球变暖潜力的替代方案，因为它避免了一次性使用塑料--可以从LCA的结果中获得信息，而决策确实是“基于科学证据”的。

Marine litter, namely plastic, is a growing environmental problem and environmental decision makers are beginning to take actions/implement regulations that aim to reduce plastic use and waste mismanagement. The government of Canada has already announced that it will ban harmful single-use plastics as early as 2021, following the lead from The European Commission. The Canadian statement also specified that the measures taken would be “grounded in scientific evidence”, meaning that evidence that such bans and new solutions are an improvement from an environmental perspective are needed to support these decisions. Life Cycle Assessment (LCA) is a tool for supporting environmental decision making that is specifically designed to allow for the identification of potential trade-offs between product alternatives e.g. a single use plastic versus paper cup. However, whilst LCA is widely used in support of decision making, there is currently no methodology for impact assessment of marine litter, including plastic, in LCA. This potentially limits the application of LCA as a tool for highlighting potential trade-offs between impact categories when assessing decisions such as plastic bans or innovative solutions. This research aims at developing the different impact pathway mechanisms in order to propose characterization models and factors, allowing the integration of impacts generated by plastic in the marine environment within the Life Cycle Assessment framework and methods. The different research axis included in this program focus on microplastics released into the aquatic and marine environment, and their complete impact pathway modelling: 1) from the fate of the plastic into the different environmental compartment and sub-compartments, 2) the exposure of the species to the particles, and 3) the effect this plastic exposure can have on the ecosystem quality damage category in LCA. In addition, the degradation of macroplastic litter into microplastic contributing to this impact pathway is also quantified. This program will therefore allow the consideration in an LCA of the potential impacts of the end-of-life of plastic-based products when occurring outside of the well-managed waste systems. This information will inform the decision makers looking at different alternatives (e.g. for a product or a packaging) to compare the potential impacts and benefits of each alternatives, without being misled, either by a perceived problem, nor by a result which does not include such impacts. By including these potential damages into LCA models, impact displacements - such as choosing an alternative that would increase global warming potential because it avoids single use plastic - can be informed by the LCA results and decisions indeed be “grounded in scientific evidence”.