Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Switzerland.
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Laboratoire Chimie Environnement (LCE), Marseille, France.
Nature. 2020 Nov;587(7834):414-419. doi: 10.1038/s41586-020-2902-8. Epub 2020 Nov 18.
Particulate matter is a component of ambient air pollution that has been linked to millions of annual premature deaths globally. Assessments of the chronic and acute effects of particulate matter on human health tend to be based on mass concentration, with particle size and composition also thought to play a part. Oxidative potential has been suggested to be one of the many possible drivers of the acute health effects of particulate matter, but the link remains uncertain. Studies investigating the particulate-matter components that manifest an oxidative activity have yielded conflicting results. In consequence, there is still much to be learned about the sources of particulate matter that may control the oxidative potential concentration. Here we use field observations and air-quality modelling to quantify the major primary and secondary sources of particulate matter and of oxidative potential in Europe. We find that secondary inorganic components, crustal material and secondary biogenic organic aerosols control the mass concentration of particulate matter. By contrast, oxidative potential concentration is associated mostly with anthropogenic sources, in particular with fine-mode secondary organic aerosols largely from residential biomass burning and coarse-mode metals from vehicular non-exhaust emissions. Our results suggest that mitigation strategies aimed at reducing the mass concentrations of particulate matter alone may not reduce the oxidative potential concentration. If the oxidative potential can be linked to major health impacts, it may be more effective to control specific sources of particulate matter rather than overall particulate mass.
颗粒物是环境空气污染的一个组成部分，它与每年全球数百万人的过早死亡有关。对颗粒物对人类健康的慢性和急性影响的评估往往基于质量浓度，同时也认为粒径和成分也起着一定的作用。氧化势被认为是颗粒物急性健康影响的许多可能驱动因素之一，但这种联系仍然不确定。研究颗粒物成分的研究表明，这些成分具有氧化活性，但结果相互矛盾。因此，我们仍然需要了解可能控制氧化势浓度的颗粒物来源。在这里，我们使用现场观测和空气质量模型来量化欧洲颗粒物和氧化势的主要一次和二次来源。我们发现，二次无机成分、地壳物质和二次生物源有机气溶胶控制着颗粒物的质量浓度。相比之下，氧化势浓度主要与人为源有关，特别是与住宅生物质燃烧产生的细颗粒二次有机气溶胶和车辆非排放产生的粗颗粒金属有关。我们的研究结果表明，旨在降低颗粒物质量浓度的缓解策略可能不会降低氧化势浓度。如果氧化势可以与主要健康影响联系起来，那么控制特定的颗粒物来源而不是总体颗粒物质量可能会更有效。
