Thanks To Newer Chemical Pollutants, The Ozone Layer May Take 30 Additional Years To Recover
Scientists believe compounds used in the manufacture of the widely-used PVC are to blame for the delay.
We realised, more than three decades ago, that our chemical pollutants were stripping the Earth of its protective ozone layer. That's when the governments around the world signed the Montreal Pact to limit the production and use of these pollutants, in an effort to stop the bleeding. Unfortunately, the chlorofluorocarbons and the hydrochlorofluorocarbons that were causing the problem, aren¡¯t the only troublemakers at play.
In fact, a recent study shows that chemicals widely used for paint stripping and manufacturing PVC, are in fact, not decaying before reaching our upper atmosphere, as previously thought. These ¡°very short-lived substances¡± are doing more damage than we realise.
The study indicates that levels of these chemicals - mainly produced in China, where they¡¯re unregulated - have increased by 60 percent over the past 10 years. And because of the damage they¡¯re causing to the upper atmosphere, it could take our ozone layer 30 additional years to repair the hole we caused so long ago.
One of these chemicals, Dichloromethane, is used as an industrial solvent and a paint remover, whereas the other, dichloroethane, is used in construction, agriculture and to manufacture PVC.
The study¡¯s authors discovered that cold winds blow these chemicals from their factories in China over the Eastern Pacific, one of the main locations where air rises up into the stratosphere. Samples indicated the chemicals reached up to 12 km into the atmosphere. ¡°This implies a route whereby these short-lived compounds can get into the atmosphere much quicker than if they had been released in North America or Manchester,¡± said lead author Dr David Oram from the University of East Anglia.
Not only are these chemicals quite valuable, but they¡¯re also toxic to workers, so the scientists are baffled as to why the factories haven¡¯t taken steps to prevent leakages. ¡°At the moment an average date for ozone recovery could be about 2050 but there are studies that say this could be delayed by 20-30 years depending on future emissions of things like dichloromethane", Oram added.
