Brace yourself for misery- it’s officially “pollenpalooza” for Chicago. A dangerous air quality alert was issued for the city after the highest pollen level in more than two decades was recorded Friday morning… Doctor Leonard Bielory, a Rutgers University researcher, explains because of the overbearing winter that never seemed to cease, tree season started late. The spring allergy season, caused primarily by tree pollination, typically begins in late February. By March birch and oak pollen have been building up, which is why now that spring is finally here and the trees are in bloom the over-due release of pollen at such a historic level.