site.btaSofia Leads Region on Low-Emission Zones, Mayor Terziev Says

Sofia Mayor Vassil Terziev said Sofia is Southeastern Europe’s first city with low-emission zones for transport and heating, Sofia Municipality said here Wednesday. Terziev spoke at the Clean Air Hub forum during London Climate Action Week

During the forum, philanthropist and UN Special Envoy Michael Bloomberg announced a USD 45 million investment to expand the global Breathe Cities network, in which Sofia is a key partner alongside cities including London, Paris, Milan and Warsaw, the municipality said.

In opening remarks to leaders from government, business and civil society, Terziev said clean air was not a luxury but a basic human right. He highlighted Sofia’s experience as the first city in Southeastern Europe to introduce low-emission zones for transport and heating. Sofia is no longer merely following global examples but has become a leader in turning international support into tangible gains for residents’ health, Terziev said.

Terziev’s programme in the British capital also included the opening of a specialist forum on technology’s role in the urban environment. He was invited as a keynote speaker for his experience in combining local government leadership with software-sector expertise. Sofia is already on this path, turning raw data into tools for better governance and public health, he said.

Data from the latest heating season show that Sofia Municipality’s comprehensive approach is working, Terziev told the forum. Sofia recorded a 22% drop in average fine particulate matter (PM10) concentrations, 52% fewer days exceeding air-quality standards than the previous winter, a 42% fall in violations in the Small Ring of the low-emission zone, showing that the most polluting vehicles are staying out of the centre, and the replacement of more than 20,000 old household stoves, cutting harmful emissions by 219 tonnes a year.

In March 2026, Sofia Municipality said the city had met the annual PM10 limit for the third consecutive year after the 2025/2026 low-emission zone produced measurable results. The municipality’s clean-air policy combines transport restrictions, limits on solid-fuel heating, stricter inspections and expanded green spaces. In December 2025, the city also used Green Tickets for public transport and tightened enforcement of the low-emission zone during a pollution episode, after which fine particulate matter and nitrogen dioxide levels fell by nearly 40% over three days.