Paint fragments as polluting microplastics: A brief review

Highlights: • Paint fragments are an understudied portion of the microplastics (MPs) in the oceans. • Most paint MPs are from ships and boats; road markings and buildings are other sources. • Paint MPs may be up to 30 times more abundant than other MPs in some regions. • Antifouling paint particles are important sources of toxic materials in the seas. • Cu and Zn are the main toxic pollutants from modern antifouling paints. Paint particles are part of the increasingly important microplastics (MPs) pollution of our oceans. They contain polyurethanes, polyesters, polyacrylates, polystyrenes, alkyls and epoxies. In spite of their prevalence, paint fragments are often excluded from MP audits. This review, citing 127 references, discusses detection, characteristics, sources and ecological effects of paint fragments in our oceans, as well as the abundance of paint fragments in MP samples around the world and their colonization by marine microorganisms, which differs from that of non-paint MPs. Paint MPs arise from shipping and boating activities, road markings and external surfaces of buildings. Many paint fragments come from antifouling paints used on commercial vessels and leisure boats; these may be regarded as particular pollutants, not only containing but also leaching heavy metals and biocides. Some effects of antifouling paint particles on aquatic biota are caused by these toxins. Paint particles are an understudied portion of marine MP pollution.