City airs normally contain the highest amounts of pollutants that are harmful to human health
Green Roofs reduce the emissions of harmful chemicals such as CO, NOx, SO2, and Particulate Matter
Study involving 170 Green Roofs in Chicago
Results showed that air pollutant removal by Green Roofs in Chicago was affected by air pollutant concentrations, weather conditions, and the growth of plants
Concluded that Green Roofs in Chicago can remove a large amount of pollutants from the air