Scientists from the University of East Anglia have identified four new man-made gases that are contributing to the damage to the ozone  layer. Two of the gases are accumulating at a rate that is causing concern among researchers.      Worries over the growing ozone hole have seen the production of chlorofluorocarbon (CFC) gases restricted since the mid 1980s. But the precise origin of these new, similar substances remains a mystery.      Lying in the atmosphere, the ozone layer plays a critical role in blocking harmful UV rays, which cause cancers in humans and reproductive problems in animals.       Scientists from the British Antarctic Survey were the first to discover a huge "hole" in the ozone over Antarctica in 1985. The evidence quickly pointed to CFC gases, which were invented in the 1920s, and were widely used in refrigeration. Extraordinarily, global action was rapidly agreed to deal with CFCs and the Montreal Protocol to limit these substances came into being in 1987. A total global ban on production came into force in 2010.      Now, the newly discovered four new gases can destroy ozone and are getting into the atmosphere from as yet unidentified sources. Three of the gases are CFCs and one is a hydrochlorofluorocarbon (HCFC), which can also damage ozone.      The research has shown that four gases were not around in the atmosphere at all until the 1960s, which suggests they are man-made. The scientists discovered the gases by analyzing polar snow pack. Air from this snow is a natural archive of what was in the atmosphere up t0 100 years ago. The researchers also looked at modern air samples, collected at remote Cape Grim in Tasmania.      They estimate that about 74,000 tonnes of these gases have been released into the atmosphere. Two of the gases are accumulating at significant rates. However, they don't know where the new gases are being released from and this should be investigated. Possible sources include chemicals  for insecticide  production and solvents   for cleaning electronic components. The three CFCs are being destroyed very slowly in the atmosphere - so even if emissions  were to stop immediately, they will still be around for many decades to come.      Of the four species identified, CFC-113a seems the most worrying as there is a very small but growing emission source somewhere, maybe from agricultural insecticides. We should find it and take it out of production. What do we know about the newly discovered gases?
Some are surely produced by the development of agriculture. The CFCs will have a long impact once they are released. They gather together in the atmosphere at a medium speed. Their amounts are not large enough to cause damage to us.