Tab. II.4.1.2 The length of the episodes with high ambient air pollution caused by PM10 in the Ostrava-Karviná area for 10 cold periods (October–March), from 1999/2000 to 2008/2009 (except March 2009)
| Length of the episodes in days | 1 | 2* | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | Total |
| Criterion: the average 24-hour concentration > 100 μg.m-3 minimally at 2 stations | |||||||||||||
| Number of episodes of the respective length for the whole assessed period | 86 | 35 | 19 | 6 | 8 | 6 | 1 | 2 | 0 | 1 | 1 | 1 | 166 |
| Average number of episodes of the respective length in one season | 8.6 | 3.5 | 1.9 | 0.6 | 0.8 | 0.6 | 0.1 | 0.2 | 0.0 | 0.1 | 0.1 | 0.1 | |
| Criterion: the average 24-hour concentration > 150 μg.m-3 minimally at 2 stations | |||||||||||||
| Number of episodes of the respective length for the whole assessed period | 44 | 17 | 5 | 1 | 2 | 1 | 2 | 1 | 0 | 0 | 0 | 0 | 73 |
| Average number of episodes of the respective length in one season | 4.4 | 1.7 | 0.5 | 0.1 | 0.2 | 0.1 | 0.2 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Maximum number of episodes of the respective length in one season | 12 | 6 | 2 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | |
* incl. the 2-day episode 19–20 April 2003