Smoke rises form chimneys of a steel plant in Ostrava, Czech Republic on November 11, 2022. [AP Photo]

Air pollution is currently the most important environmental health risk factor in Europe, the European Union (EU) environment agency warned in a report published on Friday.

"Air pollutant concentrations in 2021 remained well above the levels recommended by the World Health Organization (WHO) in its air quality guidelines," said the European Environment Agency (EEA) in the report.

"Reducing air pollution to these guideline levels would prevent a significant number of attributable deaths in EU member states," it added.

The report found that over 320,000 deaths within the European Union in 2021 were related to three main air pollutants -- fine particulate matter, ozone and nitrogen dioxide.

Some "253,000 deaths could have been avoided in the EU" if the fine particulate matter (PM2.5) concentrations had met WHO recommendations, it said.

Meanwhile, pollution from nitrogen dioxide (NO2) resulted in 52,000 deaths and short-term ozone (O3) exposure led to 22,000 deaths.

The number of pollutant-related deaths across Europe reached 389,000 when a larger set of European countries outside the EU were included, according to the report.

Exposure to air pollution causes or aggravates certain diseases like lung cancer, heart disease, asthma, and diabetes according to new estimates of health impacts, according to the EEA.