[Black microplastics in the environment: Origin, transport and risk of tire wear particles]

With the continuous growth of vehicle per capita in recent years, tire wear particles (TWP) produced by tire wear on roads have been widely found in various environmental media, whose environmental behavior and effects have attracted extensive attention. After being produced, these microsized and nanosized TWP will drift into the atmosphere or enter the surrounding soil, rivers, and even into the ocean with rain and runoff. The existence of TWP significantly affects the composition of organic materials in the environment. Meanwhile, the release of heavy metals and organic additives from TWP will be harmful to organisms and human health. We summarized the sources and characteristics of TWP, their migration and diffusion in water, atmosphere, and soil environment. By analyzing the environmental impacts and ecological risks of TWP pollution, we proposed the key questions urgently to be solved and prevention measures.