Lungs of the City (3 of 3) (image) Eindhoven University of Technology Share Print E-Mail Caption The reduction of particulate matter concentrations in the city center with the use of 594 air purification units. The darkness of the blue represents the amount of the reduction. In certain locations the reduction peaked clearly to 50 percent. The influence of the wind is very clear from this picture. Credit Eindhoven University of Technology Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.