Little Rock is high on the list because the allergy medicine usage per patient has remained “worse than average.” High weed and mold counts are to blame. “The increased pollen causes more allergy symptoms,” Dr. Borczuk says. IN addition to that, the ozone due to global warming causes more asthma suffering (The Best and Worst Workouts for Asthma) both for allergy sufferers and non-allergy sufferers, she adds.