Microscopic Pollution (IMAGE) Northwestern University Caption This is a particle of microscopic pollution (magnified 2,000 times and 10,000 times) that appears to trigger fatal heart attacks and strokes. Credit Photo by Vinayak P. Dravid 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.