The air is too toxic to breathe in a third of tested areas, a new report from the European Environment Agency shows.
Dangerous levels of nitrogen dioxide and particulate matters were found - and according to the EEA: "These pollutants can affect the cardiovascular system, lungs, liver, spleen and blood."
The report, which you can read in full here, says that it's down to the way the majority of people choose to get around. Private car use has stayed more or less steady despite the economic downturn, despite anecdotal evidence of more people taking to two wheels to save money.
Part of this is the soaring cost of rail travel - while buying a car has actually become far more affordable in real terms since the mid-1990s.
And while electric cars, and more fuel-efficient models have been proven to be genuine alternatives for drivers, they just haven't become widely used yet.
"The application of technology has been the primary means of reducing the environmental impacts of transport in the last two decades," Alfredo Sánchez Vicente, a transport expert at EEA, told the Public Service Europe website.
"But it is clear that measures for reducing the impact of transport emissions and noise can be either technical or non-technical.
"Action to reduce emissions - greenhouse gases, air pollutants and noise - from vehicles through shifting to alternative modes, the 'shift' principle, and to cleaner fuels and improved vehicle technology, the 'improve' principle, should be complemented by better managing transport demand - the 'avoid' principle.
"Growing transport demand negates many of the benefits of technology development."
The real key to getting Europeans healthier - both in terms of fitness and air quality - is to get them out of motor vehicles, he said.
"Non-motorised transport can and should play a major role in improving the quality of life of Europeans.
"The challenge is to remove barriers to commuting by bicycle, including cultural and infrastructural barriers, but also in terms of safety.
"We know that its use is exponential: the more bikes on the road, the more pleasant and less dangerous it is to commute by bike, and more infrastructure becomes available.
"All administration levels need to help trigger this positive cycle." Indeed, more bicycles in the transport mix could be a godsend.
"But it is going to take time and investment. People will not cycle if they do not feel safe and to feel safe they need adequate infrastructure. The real reason the Dutch cycle is because the the government spends on average €25 per head on cycling policies."
After an unpromising start, having to be bribed by her parents to learn to ride without stabilisers, Sarah became rather keener on cycling in her university years, and was eventually persuaded to upgrade to proper road cycling by the prospect of a shiny red Italian bike, which she promptly destroyed by trapping a pair of knickers in the rear derailleur. Sarah writes about about cycling every weekend on road.cc.