Air pollution has been of interest for a long while now, not only the mists of less than mellow fruitfulness of the '40's and the stink of December 1952 but ever since I clambered behind the wheel of a car. It was an old one with little or no exhaust and didn't half smell.
This article in FE News reminds us of how much has changed recently. But it comes with a cost. It refers to the major works that will be needed for classrooms and education facilities. It will also apply elsewhere.
One concern is that the bigger and more work that machines have to do is that they often are noisier. The noise in turn is another health issue. So do you turn off the air con' in which case the lungs get it. Or do you turn it up and give the brain a big bang?