3 ms·Also in many Asian cities masks are worn due to air pollution.by skocznymroczny 7y agoAlso in many Asian cities masks are worn due to air pollution.JCharante 7y agoand even in clean areas some people still wear them because they help keep your face warm when it's cold.Markoff 7y agoor it's just common courtesy trying to not infect others with your illness like in Japanrootsudo 7y agoOr, maybe because people go from clean to dirty areas.