Review of micro- and nanoplastic contamination in the food chain

Whereas the dramatic environmental impact of plastic waste rightfully receives considerable attention by scientists, policy makers and public in general, the human health impact of micro- and nanoplastics contamination of our food and beverages remains largely unknown. Indeed, most studies aim at understanding the environmental impact rather than the human health impact of a possible exposure to micro- and nanoplastics. In addition, these papers generally lack a methodological, standardised approach. Furthermore, some studies focus on the damage to and contamination level of animal species collected from the wild environment, and others investigate the rate and biology of microplastic uptake of animals fed with microplastics in laboratory. This review aims at understanding human exposure. Since there is, with few exceptions, no evidence available on the presence of micro- and nanoplastics in a normal diet, this study takes an indirect approach and analyses peer-reviewed publications since 2010 that document the presence of micro- and nanoplastics in those animals (more than 200 species) and food products that are part of the human food chain and that may thus contribute directly or indirectly to the uptake of micro- and nanoplastics via the human diet. It also addresses the question of the definitions, the methodologies and the quality criteria applied to obtain the reported results. This review suggests that, beyond a few estimations and comparisons, precise data to assess the exact exposure of humans to micro- and nanoplastics through their diet cannot be produced until standardised methods and definitions are available.

塑料垃圾所引发的显著环境影响，早已理所应当地获得了科学家、政策制定者乃至社会公众的广泛关注。然而，我们的食品与饮品中的微塑料与纳米塑料污染对人类健康造成的影响，在很大程度上仍未明确。事实上，当前绝大多数研究均聚焦于其环境效应，而非人类可能摄入微塑料与纳米塑料后的健康影响。此外，此类研究普遍缺乏标准化的方法论体系。部分研究针对野生环境中采集的动物物种所受的微塑料污染程度与损伤情况展开，另有研究则在实验室条件下，探究投喂微塑料后动物体内微塑料的摄取速率与生物学特性。本综述旨在阐明人类的微塑料与纳米塑料暴露情况。由于除极少数例外案例外，尚无证据证实正常膳食中存在微塑料与纳米塑料，因此本研究采用间接研究路径，分析2010年以来的同行评议文献——这些文献记录了200余个物种的动物以及属于人类食物链的食品中微塑料与纳米塑料的存在情况，而此类物质可能通过人类膳食直接或间接进入人体。本综述同时探讨了相关研究中所采用的定义、方法论与质量评价标准，以验证所得结果的可靠性。本综述指出，除少量估算与对比研究外，在建立统一的标准化方法与定义体系之前，无法获取精准数据以评估人类通过膳食摄入微塑料与纳米塑料的实际暴露水平。