This is not only about "clean air," there's also an economic component to it, it's about how the increasing burden of EU regulations suffocates those in the lower part of the society. Actually, a very interesting discussion I wish would have found more echo in this article.

At best, this onesided article presents a correlation between the adoption of these rules and the quality of air in the city, but this is not a definitive proof that the rules are actually working in the way it's suggested here...