Population heatmap of Tehran (image) Hiroshima University Share Print E-Mail Caption Dark red and dark blue indicates higher and lower levels of population density, respectively. Credit Amir Reza Khavarian-Garmsir, Ayyoob Sharifi & Nabi Moradpour Usage Restrictions News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only. 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.