Many major cities around the world have horrific air quality. Major capital cities across Europe, Asia,and the United States all have poor air quality on most days and have not accounted for the long term effects on its citizens.
This video focuses on London, one of the worst, but one of the more progressive cities that is more widely realizing the seriousness of the problem and are now starting to address it.
It is going to take years to mitigate the source of the air polluters (most diesel cars and trucks and in the meantime many more every-day citizens will suffer in the later years as a result, but future generations will benefit from the efforts now underway. Given that urban areas are home to a growing majority of the population, it is critical to from both an environmental and public health perspective.