Just been listening to the radio where a reporter based in the far east commented on his home situation. It seems he and others who live in the industrial areas of some big cities need to take protection of their family health very seriously.
He keeps his windows closed and even tries to keep out the deadly PM2.5 particles famed for their air pollution with the help of Duck Tape which he puts around the edges of windows. He mentioned that the noise from Air Purifiers in every room may be disturbing to his family life but it is a small inconvenience.
It seems a air monitoring device was obtained a few years ago and this indicated that the amount of air pollution was rated in the high eighties. since even the suggested local recommended rate was about 25, he quickly did something to help the situation and this included the Air Purifiers and the duck tape. It seems others in the area also use the air pollution monitors in their homes and are proactive in trying to reduce the risks . Yet even with the procedures described the level maintain in the reporters home is still just at 25. He did not say if there were any trees around the area-trees help to oxygenate the atmosphere(fresh country air etc) and some types of trees help reduce some types of air pollution in certain circumstances.
For information-PM2.5 particles are less than 2.5 microns in diameter. Some occur via dust storms but most via industrial processes. The smallest cross the blood barrier and are breathed in and enter the lungs and have been associated with respiratory disease and lung damage.
The World Health Organisation consider 85% of people in urban areas are exposed to these and other pollutants which are too small to see yet devastate health.