Sarajevo among world's worst cities for air quality

The city ranked fifth globally, with an air pollution index of 163, placing it in the red zone, which indicates unhealthy air, data from Swiss monitoring platform AirQuality showed. The website collects and analyses readings from monitoring stations in urban centres around the world.

Pakistan's Lahore topped the ranking, with an index exceeding 600, placing it in the brown zone, which indicates hazardous air quality.

Zagreb, by comparison, ranked 49th, with an index of 49, placing it in the yellow zone, classified as moderate.

The Federation of Bosnia and Herzegovina entity's Hydrometeorological Institute has been warning of a gradual deterioration in air quality since the middle of last week, as pollution once again builds up in urban areas across the country with the onset of colder weather.

Fine particulate matter known as PM2.5 is a major contributor to the pollution. These microscopic particles can penetrate deep into the lungs and respiratory system, posing serious health risks.

On Sunday, PM2.5 concentrations in Sarajevo reached 112 micrograms per cubic metre, a level classified as very high pollution.

The city's geography is a key factor. Located in a basin, Sarajevo experiences poor air circulation during the winter months, allowing pollutants to become trapped over the city.

The problem is compounded by heavy traffic, particularly the large number of older vehicles, and more than 43,000 registered household heating units that burn solid fuels. Often of poor quality, these fuels release substantial quantities of harmful pollutants into the air.

The combination of geographical conditions, vehicle emissions and household heating makes winter air pollution a recurring problem for Sarajevo, with residents facing deteriorating air quality year after year.