Ultrafine Dust Level Reaches ‘Bad’ Only on 17 Days Last Year
SEOUL, Jan. 16 (Korea Bizwire) — The level of ultrafine dust was bad or worse only on 17 days last year, the lowest on record, thanks to lower dust levels in China, the environment ministry said Monday. South Korea categorizes concentrations of ultrafine dust — particles smaller than 2.5 micrometers in diameter, also known as [...]