Microplastics

Microplastics are plastic particles and fibrous fragments that measure less than 5 millimeters in size. They include primary microplastics, manufactured at small sizes such as microbeads used in cosmetics, and secondary microplastics that result from the breakdown of larger plastic items through weathering, abrasion, and photodegradation. They persist in the environment and can be transported long distances.

Common sources include cosmetics, personal care products, synthetic textiles releasing fibers during washing, tire wear from road traffic, and litter that breaks down. Wastewater treatment plants and mismanaged waste can release microplastics into waterways; wind and rivers carry them to oceans and inland habitats.

Microplastics have been detected in a wide range of environments: oceans, rivers, soils, snow, and even the air. Marine and terrestrial wildlife ingest them, sometimes mistaking them for food, with potential physical and chemical impacts. Human exposure can occur through seafood, salt, drinking water, and inhalation, though the health implications for humans are not yet fully understood.

Researchers use microscopy, spectroscopy (e.g., FTIR, Raman) and mass spectrometry to identify and quantify microplastics, but methodological differences limit comparability. Policy responses include reducing leakage from consumer products (such as bans on microbeads), improving waste and wastewater treatment, and promoting product design and recycling. Ongoing work aims to standardize methods, assess risks, and identify effective mitigation strategies.