The Ioannina region is experiencing its fourth consecutive day under a cloud of smog, with particulate matter concentrations exceeding acceptable limits on December 16 and 17. High pollution levels are primarily observed during the evening. Meteorological conditions are not expected to improve until Friday, prompting authorities to advise vulnerable groups, including those with heart or respiratory issues, seniors, and children, to limit outdoor activities. The Region of Epirus is monitoring the situation and will announce any new measures if necessary.