Commercial clothes dryers: a source of microfiber emissions to air

Abstract Background . Microfibers from textiles are a major source of microplastic pollution, yet emissions from dryers are poorly studied. Objectives . This study quantifies microfiber emissions from commercial dryers and explores deposition around laundromats. Methods . We conducted atmospheric sampling using passive samplers at ten laundromats in San Francisco and quantified microfiber emissions from dryer vent lint at two locations. Results . Microfiber deposition rates were significantly higher downwind of dryer exhausts, and lint samples indicated emissions of 8–47 million microfibers per week per laundromat. City-wide emissions may reach 1.1 quadrillion microfibers annually. Conclusions . Commercial dryers are an overlooked source of airborne microfiber pollution. Mitigation strategies, including filtration, should target this source.