NO2

January 6, 2017, 5am PST
The capital of Catalunya is suffering from persistent high pollution due to car density and the largest number of motorcycles in Europe. City administrators, aware of the situation, have been unwilling to take any action that would upset drivers.
Cities of the Future
March 22, 2013, 5am PDT
Air pollution is second only to smoking as a cause of premature death in Britain. So why haven't the country's leaders taken action to address the problem?
The Guardian