Environmental organization "For the Earth" has called for a permanent ban on the most polluting cars in the center of Sofia, arguing that restrictions should not be limited to the winter months but enforced year-round. The group advocates for the "Low Emission Zone" along the capital’s small ring road to become a permanent measure in an effort to combat the growing levels of air pollution, specifically nitrogen dioxide.

Currently, vehicles in the first and second eco groups are prohibited from entering the city center between December 1 and February 28. This restriction applies to the area within Sofia's "small ring," which includes major roads such as Vasil Levski, Patriarh Evtimiy, Skobelev, Opalchenska, and Slivnitsa. Last year, the ban only applied to the first eco group, but the latest measures are expected to impact around 140,000 of the most polluting vehicles.

The environmental group points to new data showing concerning levels of nitrogen dioxide pollution across the city. Between November 2023 and February 2024, air quality measurements revealed that in 34 out of 36 monitored locations, NO₂ concentrations exceeded the annual average threshold of 40 µg/m³. The pollution levels were notably higher than those recorded in 2021 and 2022, suggesting the situation is worsening.

The report also highlighted that nitrogen dioxide concentrations are alarmingly high in various urban areas where many people live and work, such as residential neighborhoods, commercial districts, and near schools and public transport hubs. Higher concentrations of NO₂ were observed along busy streets and major boulevards, reaffirming that vehicles, especially diesel-powered ones, are the primary source of these harmful emissions.

These findings are troubling, as they indicate that Sofia lacks sufficient, effective measures to address the rising nitrogen dioxide pollution from traffic. "For the Earth" argues that the city needs stronger actions to reduce emissions and improve air quality for its residents.