On Thursday, Sarajevo was shrouded in a dense fog that led to flight cancellations, halted outdoor construction, and kept children indoors as a safety measure. The Bosnian capital is no stranger to such conditions, especially during winter months when pollution from heating and traffic becomes rampant.

Sarajevo’s geographical position, nestled within a valley surrounded by mountains, often traps polluted air when there is a lack of wind to disperse it. This scenario is a familiar challenge for the city as it grapples with poor air quality during the colder seasons.

Amidst the morning rush hour, visibility was significantly reduced, causing cars to move at a cautious pace. Meanwhile, several flights scheduled to depart from Sarajevo Airport were canceled. Many residents took to wearing face masks as a protective measure against the smog-laden air.

According to IQAir, a Swiss company specializing in air quality technology, Sarajevo’s air was categorized as “unhealthy” on Thursday. The city frequently ranks among the worst globally for air pollution.

In response to the hazardous conditions, city officials have imposed restrictions, including a ban on vehicles over 3.5 tonnes and those not compliant with European Union environmental standards within the city center. Outdoor construction activities and public gatherings have also been suspended.

Health experts have raised alarms over the exposure to PM2.5 particles—tiny inhalable pollutants less than 2.5 micrometers in diameter. Such exposure is linked to an increase in respiratory infections, cancer, cardiovascular diseases, and premature deaths in Sarajevo and other major cities throughout Bosnia and the Western Balkans.

Many Balkan countries have a poor record in environment protection despite promises to improve the situation as they seek to move closer to EU membership. Balkan rivers are often clogged with garbage and recycling is almost non-existent, while many cities have seen rampant construction diminishing green areas.

The air in Belgrade, the capital of neighbouring Serbia, also was deemed “unhealthy for sensitive groups” on Thursday.