ISTANBUL

North Macedonia's capital Skopje and Kosovo's capital Pristina, which recorded hazardous air quality levels Monday, rank among the most polluted major cities globally, according to air quality monitor IQAir.

The two capitals are currently the only European cities in the top 20, ranking seventh and 19th on the most polluted major cities list.

Skopje registered an "unhealthy" air quality index of 178 at 1900GMT, with PM2.5 pollution levels 18.7 times higher than World Health Organization (WHO) guidelines. The city's air quality worsened to 193 overnight.

Pristina showed similarly dangerous levels with an index of 153, reaching 198 overnight. Its PM2.5 concentration measured 11.7 times above WHO recommended limits.

PM2.5 refers to atmospheric particulate matter with a diameter less than 2.5 micrometers, which can penetrate deep into the lungs.

Health experts advise residents in both cities to avoid outdoor exercise, keep windows closed, use air purifiers and wear masks outdoors.

The United States Air Quality Index (AQI) measures air quality on a scale from 0 to 500, with values over 150 posing health risks to the general public and serious risks to sensitive groups.

The WHO highlights that 99% of the global population breathes air exceeding safe pollution levels.