A woman covering her mouth with a surgical mask
A woman covering her mouth with a surgical mask and scarf crosses the street in central Seoul, Friday, when the city government issued a warning against a high concentration of ultrafine dust. / Yonhap
A woman covering her mouth with a surgical mask and scarf crosses the street in central Seoul, Friday, when the city government issued a warning against a high concentration of ultrafine dust. / Yonhap