Seasonal allergies are everywhere, though some places are harder to live than others. The Asthma and Allergy Foundation of America (AAFA) identified the most challenging places to live with fall allergies in 2014. Click through to see how your city ranks. (Thinkstock/Comstock)
Scientists examined the affect of CO2 and ozone levels on grass and pollen production and found that by the end of the century, levels could increase more than 200 percent.