Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400, Oostende, Belgium.
Flanders Marine Institute (VLIZ), Research Department Ocean and Human Health, InnovOcean Campus, Jacobsenstraat 1, 8400, Oostende, Belgium.
Environ Pollut. 2024 Jun 15;351:124105. doi: 10.1016/j.envpol.2024.124105. Epub 2024 May 4.
Micro- and nanoplastics (MNPs) can enter the atmosphere via sea spray aerosols (SSAs), but the effects of plastic characteristics on the aerosolization process are unclear. Furthermore, the importance of the transport of MNPs via these SSAs as a possible new exposure route for human health remains unknown. The aim of this study was two-fold: (1) to examine if a selection of factors affects aerosolization processes of MNPs, and (2) to estimate human exposure to MNPs via aerosols inhalation. A laboratory-based bubble bursting mechanism, simulating the aerosolization process at sea, was used to investigate the influence of MNP as well as seawater characteristics. To determine the potential human exposure to microplastics via inhalation of SSAs, the results of the laboratory experiments were extrapolated to the field based on sea surface microplastic concentrations and the volume of inhaled aerosols. Enrichment seemed to be influenced by MNP size, concentration and polymer type. With higher enrichment for smaller particles and denser polymers. Experiments with different concentrations showed a larger range of variability but nonetheless lower concentrations seemed to result in higher enrichment, presumably due to lower aggregation. In addition to the MNP characteristics, the type of seawater used seemed to influence the aerosolization process. Our human exposure estimate to microplastic via inhalation of sea spray aerosols shows that in comparison with reported inhaled concentrations in urban and indoor environments, this exposure route seems negligible for microplastics. Following the business-as-usual scenario on plastic production, the daily plastic inhalation in coastal areas in 2100 is estimated to increase but remain far below 1 particle per day. This study shows that aerosolization of MNPs is a new plastic transport pathway to be considered, but in terms of human exposure it seems negligible compared to other more important sources of MNPs, based on current reported environmental concentrations.
微塑料和纳米塑料（MNPs）可以通过海雾气溶胶（SSAs）进入大气，但塑料特性对气溶胶化过程的影响尚不清楚。此外，通过这些 SSAs 运输 MNPs 作为人类健康新的暴露途径的重要性尚不清楚。本研究的目的有两个：（1）检查是否有一系列因素会影响 MNPs 的气溶胶化过程；（2）估计人类通过气溶胶吸入暴露于 MNPs 的情况。采用实验室基于气泡破裂的机制模拟海上海雾气溶胶化过程，研究了 MNPs 以及海水特性的影响。为了确定通过吸入 SSAs 摄入微塑料对人类的潜在暴露，根据海面微塑料浓度和吸入气溶胶的体积，将实验室实验结果外推到现场。浓缩似乎受 MNP 尺寸、浓度和聚合物类型的影响。较小的颗粒和密度较高的聚合物浓缩程度更高。不同浓度的实验显示出更大的变异性，但浓度较低的实验似乎会导致更高的浓缩，可能是由于聚集程度较低。除了 MNP 特性外，所使用的海水类型似乎也会影响气溶胶化过程。通过吸入海雾气溶胶摄入微塑料对人类的暴露估计表明，与城市和室内环境中报道的吸入浓度相比，这种暴露途径对微塑料来说可以忽略不计。按照目前塑料产量的照常情景，预计 2100 年沿海地区每天通过塑料吸入的量会增加，但仍远低于每天 1 个颗粒。本研究表明，MNPs 的气溶胶化是一种新的塑料传输途径，需要加以考虑，但就人类暴露而言，与其他更重要的 MNPs 来源相比，根据目前报告的环境浓度，这种途径似乎可以忽略不计。
