Air pollution

Thick fog, smoke, and coughing residents marked the start of 2025 in Bulgaria's major cities, including Sofia. The polluted air was unmistakable, and official data confirmed the problem. On December 31, 2024, the Executive Agency for the Environment reported PM10 levels nearly twice the recommended limit, highlighting the persistent air quality issues.
Although pollution levels have dropped slightly into the "moderately polluted" range according to most sensors, the thick fog blanketing the capital during the holidays revealed that traffic isn't the sole culprit. Fireworks and stagnant air due to a lack of wind exacerbated the situation, but underlying issues remain unaddressed.
Despite being a European capital, Sofia has consistently ranked among the most polluted cities in the EU. The previous municipal administration introduced incomplete measures, leading to a 2021 court ruling holding the municipality accountable for failing to act decisively. The court mandated improvements in public transport, restrictions on older vehicles, and a transition from solid fuel heating by the end of 2022. However, many of these directives were only partially implemented under former mayor Yordanka Fandakova.
Newly elected Mayor Vasil Terziev has made combating air pollution a central goal. Last year, he announced plans for Sofia to achieve net-zero emissions by 2030, with promises of substantial investments in sustainable infrastructure, green transportation, and enhanced air quality monitoring. However, criticism persists regarding the reliability of the city’s air monitoring system.
Concerns about inadequate monitoring date back to at least 2022 when the Ministry of Environment and Water acknowledged deficiencies in Sofia’s air measurement network. Reports revealed that the system significantly underestimated nitrogen dioxide levels. Mayor Terziev recently disclosed that the data collected by this network could deviate by as much as twelvefold. To address this, he pledged to establish a new, more accurate monitoring network, though progress on this front has been slow. Opposition voices, particularly from GERB, have criticized Terziev for not resolving these longstanding issues within his first year in office.
In 2024, the Sofia Municipal Council approved several measures aimed at reducing pollution. These included lower thresholds for implementing PM10 restrictions and introducing green and white public transport tickets to encourage residents to opt for public transit over personal vehicles on highly polluted days. Low-emission zones were also designated in central Sofia, restricting access for older, high-emission vehicles.
Among the primary sources of pollution are domestic solid fuel heating and industrial zones near the city. Efforts are underway to provide alternative heating options to households, though the pace has been slow. Enhanced inspections of industrial areas are also planned as part of the broader strategy to improve air quality.
Despite these initiatives, significant work remains to achieve the ambitious goal of cleaner air for Sofia’s residents. For now, the start of 2025 serves as a reminder of the challenges ahead.