Pollution in Mexico City (IMAGE) Colorado State University Caption This photo of Mexico City, taken in 2006, was part of the MILAGRO or Megacity Initiative: Local and Global Research Observations field campaign led by the National Center for Atmospheric Research. Scientists around the globe, including atmospheric chemists at Colorado State University, are studying aerosols and their contribution to pollution in the atmosphere. Credit Sasha Madronich at the National Center for Atmospheric Research Usage Restrictions None License Licensed content 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.