Anthropocene airborne microfibers: Physicochemical characteristics, identification methods and health impacts

The toxicity of fibrous particles in ambient air can be higher than that of particles of other shapes; a phenomenon referred to as the fiber paradigm. Microfibers (MFs) can be classified into organic and inorganic types. Airborne inorganic fibers originate from the suspension of dust from roads, construction sites, industries, and also natural dust storms. While the use of carcinogenic mineral fibers, such as asbestos, is now restricted, their substitutes, such as artificial mineral fibers, are still widely used due to their comparable properties. With the rapid growing consumption of plastic products in recent decades, plastic MFs have emerged as a new source of anthropogenic pollutants, as well as markers of the Anthropocene, focusing scientific attention in terms of environmental concerns. MFs in the ambient atmosphere can lead to adverse human health effects following ingestion via the gastrointestinal tract or inhalation through the respiratory system. Accurate collection and identification of MFs, standardization of analysis procedures, and the understanding of the underlying health hazards are critical for scientists and governments to develop public health mitigation strategies. This review classifies ambient atmo-spheric MFs according to their morphology and compositions. Current understandings on the physical and chemical characteristics of mineral and plastic MFs are summarized. A comparison of the various identification methods used for atmospheric MFs is presented, and a standardized protocol is proposed. The toxicity and health impact mechanisms of atmospheric MFs are also discussed. We recommend the development of sensitive, ac-curate and rapid detection methods, with a strong emphasis on source apportionment.

Automated summary

The toxicity of fibrous particles in ambient air can be higher than other types of particles. Microfibers can be organic or inorganic and their presence in the atmosphere as a result of human activity raises concerns for environmental and public health. Accurate collection, identification, and understanding of the health hazards associated with these fibers are crucial for mitigation strategies and protection of public health.