Evaluation of micro- and nanoplastics in Canadian drinking water, their role as vectors of pathogen and chemical transport and associated health risks

饮用水在饮用前进行处理以去除物理、化学和生物污染物。为了减少健康风险，确保向消费者提供清洁、安全的饮用水，加拿大各地都实施了相关法规。最近在对世界各地经过处理的饮用水进行的有限研究中发现了微塑料和纳米塑料，对消费者构成未知的风险。微塑料被定义为尺寸在1到5000微米之间的合成聚合物；纳米塑料是指尺寸小于1微米的颗粒。尽管人们普遍认为许多水源受到了不可逆转的微塑料和纳米塑料污染，但加拿大各地采用的传统和先进水处理工艺对它们的去除了解甚少。因此，目前尚不清楚与摄入这些颗粒有关的潜在健康影响。拟议的研究将检查加拿大各地设施中原始（未经处理）和处理过的水中微塑料和纳米塑料的浓度和特征。在这一初步数据收集之后，这项研究的重点将是填补与饮用水中微塑料和纳米塑料消费对健康的潜在影响相关的知识空白。据推测，塑料颗粒可能运输化学和生物（如病原体）污染物。这项研究将有助于量化化学吸附和表征生物膜的发展和组成的原始和环境风化的塑料颗粒的不同大小。从微塑料和纳米塑料中提取的污染物也将通过一系列基于细胞的生物测定来评估潜在的毒性途径。这项研究代表了对加拿大饮用水中微塑料和纳米塑料的最全面的已知检查，并将提供对塑料的化学和生物污染的深入评估。

Drinking water treatment is conducted to remove physical, chemical and biological contaminants prior to consumption. Regulations have been implemented across Canada to reduce health risks and ensure clean, safe drinking water is provided to consumers. Micro- and nanoplastics have recently been identified in limited studied of treated drinking waters from around the world, posing an unknown risk to consumers. Microplastics are defined as synthetic polymers between 1 and 5,000 µm in size; nanoplastics represent particles which measure <1 µm. Although it has been widely accepted that many source waters are irreversibly contaminated with micro- and nanoplastics, their removal by conventional and advanced water treatment processes employed across Canada is poorly understood. As such, the potential health impacts associated with the consumption of these particles is currently unknown. The proposed research will examine the concentration and characteristics of micro- and nanoplastics in raw (untreated) and treated water at facilities across Canada. Following this initial data collection, the emphasis of this research will be to fill the knowledge gap associated with the potential health impacts related to consumption of micro- and nanoplastics in drinking water. It has been hypothesized that plastic particles may transport chemical and biological (e.g. pathogen) contaminants. This research will serve to quantify chemical sorption to and characterize biofilm development and composition on virgin and environmentally weathered plastic particles of various sizes. Contaminants extracted from the micro- and nanoplastics will also be examined through a series of cell-based bioassays to evaluate potential toxicity pathways. This research represents the most comprehensive known examination of micro- and nanoplastics in Canadian drinking water and will provide an in-depth evaluation of chemical and biological contamination on plastics.