Stratospheric Balloons (IMAGE) University of East Anglia Caption Scientists at the University of East Anglia have used mass spectrometers to analyze air samples collected in the stratosphere by these balloons. Their discovery could make it possible in future to identify the source of banned CFCs that are probably still being released into the atmosphere. They also discovered the largest chlorine isotope enrichment ever found in nature. Credit Andreas Engel Usage Restrictions Paper under embargo to 14.00 EST, 19.00 BST 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.