A new study shows that using an E15 blend instead of regular gasoline would reduce smog in Chicago. Increasing the availability of the 15-percent ethanol blend could help reduce carcinogenic air pollution and improve air quality, particularly on the city's South Side. The study found that E15 reduces the risk of cancer by 6.6 percent. It also reduces greenhouse gas emissions 1.5 percent compared to a 10-percent ethanol blend. Read more at Domestic Fuel.