Fine particle air pollution led to 238,000 premature deaths in the European Union in 2020, the environmental watchdog European Environment Agency (EEA) has said.
This was a slight rise from the previous year, despite a fall in emissions due to Covid-19 curbs.
The report says that the Covid-19 pandemic led to the deaths of some people already living with diseases related to air pollution.
Across the 27 countries "exposure to concentrations of fine particulate matter above the 2021 World Health Organization guideline level resulted in 238,000 premature deaths," the EEA said.
Fine particulate matter, or PM2.5, is a term for particulates which are typically the by-product of car exhausts or coal-fired power plants.
Their tiny size enables them to travel deep into the respiratory tract, worsening the risk of bronchitis, asthma and lung disease.
Also in 2020, exposure to nitrogen dioxide (NO2) above the WHO's recommended threshold led to 49,000 premature deaths in the EU, the EEA said.
Acute exposure to ozone (O3) caused 24,000 people to die early.
"When comparing 2020 to 2019, the number of premature deaths attributable to air pollution increased for PM2.5 but decreased for NO2 and O3," the agency said.
"For PM 2.5, falls in concentrations were counteracted by an increase in deaths due to the pandemic."
The EU wants to reduce premature deaths related to fine particulate matter pollution by 55% in 2030 compared to 2005 levels.
Overall, the rate for EU countries in 2020 was 45% lower than in 2005, the agency said.
"If this rate of decline is maintained, the EU will reach the aforementioned zero pollution action plan target before 2030."
According to the WHO, air pollution causes seven million premature deaths per year worldwide, putting it on par with smoking or poor diets.