A man rides past a hazy Han River Park in Seoul on Sunday.
Toxic haze from China was is being blown over to Korea much earlier than usual. The density of ultrafine or PM2.5 particles reached 70-100 / in the Seoul metropolitan area and South Chungcheong and North Jeolla provinces over the weekend, the worst this fall and three to five times worse than the usual 20-30 / in early September.
According to the Korea Environment Corporation on Sunday, fine dust concentration was especially high in western parts. In Gyeonggi Province density reached up to 73 / per hour last Thursday, 104 / on Friday and 109 / on Saturday. In Incheon levels hovered between 70 and 100 / and in Seoul between 76 and 93 /.
The reason is that northwesterly winds carried fine dust from China while the air stood still above western Korea, according to the National Institute of Environmental Research.
The haze usually starts in October but it came a month earlier this year. Fine dust levels will fall due to the rain on Monday, the institute said, but dust influx may increase as autumn progresses.