The Ministry of the Environment issued an ozone warning for Suwon, Gyeonggi Province, Wednesday, where the 2002 World Cup Group D soccer match between Portugal and the United States will be held. The ministry said the density of ozone reached 0.122ppm at 3:00pm, which was why it issued the warning.

Prior to this, the first warning of the year was issued at Euijeongbu, Gyeonggi Province where the density was measured at 0.124ppm at 1:00pm, followed by Pyeongtek and Gimpo at 2:00pm.

The ozone warning system was introduced first in Seoul 1995 and is issued in 28 cities nationwide when the concentration is above 0.12ppm. Concentrations of 0.3ppm rate an alarm and above 0.5ppm, a serious alarm. Last year there were a total of 29 warnings on 15 days. (Park Don-kyu, coeur@chosun.com )