The answer is no surprise. Very recently the World Health Organisation has reviewed scientific studies carried out on air pollution and has now classified it as carcinogenic. For the first time the air pollution around us has been acknowledged to cause cancer. Specifically lung and bladder cancers were top of the list in the studies conducted.
The WHO creates reports and categorisations like this to help governments decide how to create policies and run their countries. It's going to be interesting to see if our government changes anything in the near future. Sure, our air pollution is not nearly as bad as some other countries, but at the same time it's much worse than some that take more care in preventing pollution.
I think the main issues are going to be for those that live in or near heavily industrialised areas or in the middle of cities with a lot of traffic as that's where the largest build up of air pollutants is going to be. But what can you do about it? My advice would be to spend more time escaping the polluted areas and visiting the countryside. There really is a noticeable difference in the air in the countryside and this should do you good. I'm not sure whether it will counteract the effects of being exposed to pollutants, but it takes you away from them for a period of time which can only be a good thing.
As for other ways to protect yourself and your families from issues my advice would be to ensure you're living and eating as healthily as possible. Doing so will give you body the tools to help fight the stress caused by the pollutants and probably give you a better chance of staving off any cancers.
On the flip side, don't read this article and go running out of the city and never return. It's about being smart with the information you have available to you and reducing risks. Avoid pollutants when you can. When you can't avoid them try and reduce your exposure as much as possible.