The Scottish capital also ranked second in terms of traffic congestion, a Clean Cities campaign study found.
Glasgow was not included in the “broad list” of cities of “international importance” chosen for the investigation, but Friends of the Land of Scotland (FoES) expressed their hope that Scotland’s largest city would be included in future versions.
Edinburgh was ranked 31st overall across a range of criteria that also included pedestrian and cyclist safety and public transport, measured in 2017-2019 before the Covid pandemic.
Oslo took first place, followed by Amsterdam, Helsinki, Copenhagen and Paris.
All the cities that did worse than Edinburgh were in Italy and Poland: Rome, Gdansk, Sopot and Gdynia, Warsaw, Krakow and Naples.
Worse in improving air quality was only Tri-City.
The report, compiled by consultants Ricardo Energy & Environment, comes out three months before a low-emission zone is due to be introduced in central Edinburgh in May.
Only cars with the cleanest engines available will be allowed, though implementation is not due to begin until June 2024 after a two-year grace period.
FoES transport campaigner Gavin Thomson said: “This awkward ranking shows just how badly Edinburgh needs a low emission zone.
“Transport air pollution puts the health of residents at risk and was at unacceptable levels until some cars disappeared from the roads due to the pandemic.
“The low emission zone will restrict the movement of the most polluting vehicles from the city center.
“This could come along with lower speed limits, bike lanes and larger pedestrian areas to catch up with the rest of Europe.
“Cities across Europe that compete with Edinburgh for investment, for tourism, for status, have long since switched to sustainable transport.
“Edinburgh and all cities in Scotland must quickly catch up and make their cities livable, green and healthy places.”
Edinburgh’s low emission zone: what the coming changes will mean for you
Oliver Lord, UK head of Clean Cities, said: “High levels of congestion and slow traffic means Edinburgh is lagging behind most European cities in the race for zero emission mobility.
“If we want cities to be greener, healthier and more prosperous, the toolbox hasn’t changed – we just need to act: less polluting cars and more space for people.”
However, Lesley Macinnes, spokesperson for Edinburgh City Council for Transport and the Environment, said: “Our own air quality monitoring shows an improvement across the city, reflected in the city’s 11th position in the current air quality rankings in this report.
“Of course, this does not mean that there is no need to do a lot of work to reduce air pollution, solve the problem of congestion and significantly improve and maintain access to sustainable transport in the city.
“However, we are up to the challenge and we currently have a long list of ambitious transport overhaul projects in and around Edinburgh.
“In the coming months, we hope to receive approval for a low emission zone that will reduce harmful emissions in the densely populated city center and also update our air quality action plan for consultation.”
McInnes said the council’s goal of reducing traffic by 30 percent by 2030 is “key to addressing congestion,” but “big steps” have been taken to improve other modes of transport so that it can be met.