Researchers at the University of East Anglia (UEA) have found two new types of chlorofluorocarbons (CFCs) and one new hydrochlorofluorocarbon (HCFC).
The latest discovery came after UEA researchers identified four new man-made gases which contribute to destruction of the ozone layer in March, bringing the total of newly discovered CFCs and HCFCs to seven.
The scientists discovered the gases by comparing today's air samples with air collected between 1978 and 2012 in unpolluted Tasmania. The research has been published in the journal Atmosphere. The new gases are at much lower concentrations than those found earlier this year, and are unlikely to pose a threat to the ozone layer, the scientists said. But the researchers speculated there were many more gases in the atmosphere, which could have a cumulative impact.
Dr Johannes Laube, from UEA's School of Environmental Sciences, said: "Two of the gases we found earlier in the year were particularly worrying because they were still accumulating significantly up until 2012.
"Emission increases of this scale have not been seen for any other CFCs since controls were introduced during the 1990s, but they are nowhere near peak CFC emissions of the 1980s."