Dirty air in 10 cities reports to the Executive Environment Agency. The most serious pollution yesterday was in the Trakia district in Plovdiv. Pollution also occurs in Vidin, Lovech, Gorna Oryahovitsa, Sliven and Shumen. Above the norm are the indicators for the metropolitan districts Nadezhda, Hipodruma, Pavlovo and Mladost.

In 2017, the cars in Sofia increased dramatically. Only the new Sofia registrations were nearly 64,000 - or an average of 190 cars per day. The municipality will try to limit their access to the center. If there is a 4-fold pollution forecast the "blue zone" will be banned.