Yes very true it is @suesa
The more visible the population can cause some life-threatening diseases, as you mentioned breathing, skin allergies and some other diseases caused by the air population that can not be ignored.
But there are other effects that cause the disease, but never realized that people consume food everyday. Eating is the main factor to be noticed, because every day the food menu will be more modern, so the food is no longer natural. Lots of toxic flavors, dyes and other very dangerous ingredients.