SARAJEVO, Bosnia-Herzegovina — People in all major cities across the western Balkans face alarming levels of air pollution that are reducing their life expectancies because the underdeveloped, politically fragile region is still heavily reliant on burning coal to generate power, the UN said Monday in a new report.

The report released by the UN Environment Program was prepared in cooperation with the World Health Organization and air quality management institutions in Albania, Bosnia, Kosovo, Montenegro, North Macedonia and Serbia. It was based on data collected for a minimum of 274 days per year.

“The population is exposed to some of the highest concentrations of air pollution in Europe, up to five times higher than the national and the EU guideline levels,” the report said, identifying the region’s lack of access to modern renewable energy sources as a major cause of its air pollution.

Fifteen active coal-fired power plants, some of them obsolete, in five western Balkan countries pump substantial amounts of sulphur dioxide, nitrogen oxide and dust or particulate matter into the air. Also, as many as 88 percent of the region’s 7.3 million buildings use decentralized heating systems that use power inefficiently.

In the 18 major cities analyzed, the report said air pollution was causing a substantial number of premature deaths. It said, on average, 20 percent of the estimated 130,000 years of life that have been lost over a 10-year period due to air pollution were taking place before age 65.

“Air pollution in the Western Balkan cities causes between 15 percent and 19 percent of total mortality and reduces life expectancy by between 1.1 and 1.3 years,” the report said.

The report says, in the Balkan cities that were examined, the daily health restrictions for exposure to large-diameter particles of soot and other matter, or PM10, were exceeded between 120 and 180 days per year. That is much higher than allowed by national and EU laws, which restrict the number of such days to only 35 a year.