Dealing with Allergies Respiratory allergies are caused by pollen. mold or dus that circulates in the air. Allergies are quite common, especially during the spring when flowers and other plants start to bloom. However, it is virtually impossible eliminate the various to plants and trees in one city that cause respiratory allergies. The only practica solution is to move to less humid climates where fewer pollinating plants grow The state of Arizona in the United States has become a popular retirement place for elderly people many of whom suffer from allergies). There fewer cases of are pneumonia and other winter-related illnesses. En retirement com es have sprung up in Arizona due to the dry climate.