Seoul issues first ozone warning this year
An ozone warning is seen on an electronic display near Seoul City Hall, May 23. Yonhap
Seoul saw its first ozone warning of the year take effect Monday in most parts of the city.
The Seoul city government said the warning was issued at 2 p.m., as ozone density in the 21 districts of the city was between 0.123 and 0.137 parts per million (ppm).
Four other districts were excluded, it said.
Ozone warnings are issued when concentration levels reach an average of 0.12 ppm per hour. More serious alerts are issued at 0.30 ppm and 0.50 ppm, respectively.
Patients with respiratory diseases, the elderly and children are advised not to go outside when such warnings are issued. (Yonhap)