Code yellow has been declared in ten regions in Bulgaria today because of fog. In many cities in the country high levels of air pollution have been reported again. According to the European Commission's "Air Quality Index", this morning,  particulate matter concentration is well above the norms in large cities.

Most polluted is the air in three residential districts in Sofia-Mladost, Nadezhda and Hipodruma, where air pollution is 5 times above the norms of fine particulate matter. The residents of Plovdiv, Gorna Oryahovitsa, Shumen and Veliko Tarnovo also breathe highly-polluted air. Air pollution in these Bulgarian cities is 4 times above the norms of fine particulate matter. Less pollution is reported in Varna, Burgas, Haskovo, Kardzhali and Smolyan. At the advice of pulmonologists, people with chronic respiratory and cardiovascular diseases should avoid a prolonged stay outdoors.

In Sofia the municipality has introduced a Green Ticket at a price of BGN 1 for the entire city transport network today in order to reduce traffic and pollution.