Transport and transformation of atmospheric metals in ecosystems: A review

Human activities emit large amounts of metals into the atmosphere, and which migrate or settle with atmospheric activities, thus entering the ecosystem. Atmospheric metals can be harmful to humans, soil and plants when they enter the ecosystem. This review provides an overview of the processes by which atmospheric metals enter plants, soils, water bodies, humans, and mountainous areas, and the hazards arising from atmospheric metals. Atmospheric metals are transported by adsorption on the surface of particles as they migrate and enter the ecosystem through sedimentation. Atmospheric metals enter plants in two ways: they are absorbed by the leaves of the plants and by the roots of the plants after deposition on the ground. The absorption of metal particles by the blade depends mainly on the size of the particles and the surface structure of the blade. The uptake of metals by roots is mainly related to the form and type of metals, deposited atmospheric metals have a higher biological activity and are more easily absorbed by plants compared to soil metals. The human body absorbs metals from the atmosphere through skin absorption, respiratory absorption and food intake, of which food intake is the main route, and most of metals are more harmful to children. Atmospheric metals enter water bodies mainly through deposition as well as surface runoff after rain. When atmospheric metals enter water bodies, they are mainly deposited in the sediments. Atmospheric metals are deposited into local ecosystems through atmospheric transport to remote areas, and atmospheric metals input is generally the main source of pollution in remote areas because they are less disturbed by humans. Atmospheric metals are widely migratory, persistent and toxic, so understanding their transport and transformation in the ecosystem plays an important role in the control of metals in the atmosphere.