In 41 European countries, 534,471 premature deaths in 2014 can be linked to air pollution, the European Environment Agency (EEA) reported. Within the 28 countries of the European Union, that figure is 502,351.
Germany saw the highest number of deaths attributable to all air pollution sources, at 80,767. It was followed by the United Kingdom (64,351) and France (63,798). These are also the most populated countries in Europe.
"As a society, we should not accept the cost of air pollution," EEA Executive director Hans Bruyninckx said in a statement.
Transport, agriculture, power plants, industry and households are the biggest emitters in Europe, the agency said.
Investing in cleaner transport, energy and agriculture can help tackle this problem, Bruyninckx continued.
Despite these deaths, air quality in Europe has gradually improved, the EEA also pointed out.
Fine particulates most deadly
The EEA based its numbers on measurements of fine particulate matter (PM 2.5), nitrogen dioxide (NO2) and smog (O3).
According to the report, fine particulate matter alone accounted for around 428,000 of these premature deaths in all of Europe (399,000 in the EU).
Particulate matter is largely generated by vehicular traffic, but also comes from agriculture, energy production, industry and heating.
NO2 is a pollutant that can primarily be traced back to diesel fuel combustion. European cities such as Stuttgart have struggled with nitrogen dioxide emissions repeatedly exceeding permitted limits.
Ground-level smog or ozone (O3) is produced when sunlight reacts with nitrogen oxides and a volatile organic compound in the atmosphere. Nitrogen oxides (NOx) come from car exhaust, coal power plants, and factory emissions.
NOx, which also include nitrogen dioxide, are the pollutants at the center of the Dieselgate scandal, where numerous automakers were shown to have manipulated sensors to indicate fewer emissions in testing than cars actually produced on the road.
Further action required
"The European Commission is committed to tackling this and help member states make sure that the quality of their citizens' air is of the highest standard," Karmenu Vella, EU commissioner for the environment, said in a statement.
Jürgen Resch, head of Environmental Action Germany (Deutsche Umwelthilfe), pointed the finger at the auto industry and politicians - including German Chancellor Angela Merkel.
"The frightfully high proportion of premature deaths through poisonous diesel emissions is a result of the criminal practice of auto manufacturers," Resch said in a statement, referring to Dieselgate.
Environmental Action Germany reiterated its call for a ban on diesel vehicles.
The EEA report also placed special emphasis on greenhouse gases, pointing out that agriculture is a major source of this and other air pollutants.
The figures were released Wednesday in the agency's 2017 report on air quality in Europe.