Tropospheric ozone in the Czech Republic, 1994-2000

Air pollution is changing the ecosystems, especially in Europe. Tropospheric ozone may adversely
affect tree growth, with critical levels for ozone being exceeded in many parts of Europe, especially in
the Czech Republic. This research reports the information on exceedances of ozone threshold values
for the period 1994 to 2000 and gives an evaluation of the observed exceedances of the thresholds during
the vegetation period (April-September) and from May to July at the Bílý Køíž station. The threshold
for warning of the public (240 ìg m-3 as hourly average concentration) was not exceeded at the Bílý
Køíž station for the studied period. The threshold value for information to the population (180 ìg m-3
as hourly average concentration) was exceeded in 1994 (July and August), 1995 (May and July), 1998
(August) and 2000 (June). The threshold value set for the protection of human health population (120
ìg m-3 as eight-hourly average concentration) was exceeded for all period at the Bílý Køíž station.