Gyeonggi Province issued ozone warnings for 17 cities and counties within the province Saturday noon.
 
The maximum ozone concentration in the air in central Gyeonggi Province including Seongnam and Ansan cities is measured at zero-point-123 parts per million. 
 
The ozone rate is reported at zero-point-12 ppm in the eastern region including the cities of Uijeongbu and Namyangju.
 
An ozone warning is issued when the atmospheric concentration is over zero-point-12 ppm per hour.
 
A provincial official has urged children, the elderly and patients with respiratory or heart ailments to refrain from going outdoors.