Norwich, England -- A new way to measure atmospheric gases could track down sources of CFCs thought to be slowing the recovery of Earth's ozone layer, European researchers say.
CFCs, chlorofluorocarbons, were used in refrigerants and aerosol propellants until restricted by a global treaty in 1987, but they have stayed in the air longer than many expected, the BBC reported Friday.
A team of British and German researchers says it is now possible to chemically "fingerprint" CFCs to potentially trace their origin.
The scientists worked on samples of atmosphere retrieved from 115,000 feet in the stratosphere by French space agency balloons.