Article by: Nicole La Force, Forestry Department
So what about earth’s ozone layer? It’s that protective gaseous shield blue in color that sits 15 to 30 km above earth or in earth’s stratosphere. It’s made up of a highly reactive three oxygen molecule and serves as a protection by filtering out the harmful ultraviolet B radiation (UV- B) emitted by the sun which harms living cells causing skin cancer and cataracts in humans and harm animals as well.
The main culprits causing ozone depletion are pollutants containing chlorine and bromine. In the last 50 years chlorofluorocarbons (CFCs) were highly used in aerosol sprays, freezers, refrigerators and AC units. When CFCs reach the upper atmosphere, they are exposed to ultraviolet rays, which cause them to break down into substances that include chlorine. The chlorine reacts with the oxygen atoms in ozone and rips apart the ozone molecule thereby precipitating global warming and allowing greater quantities of UV- rays to reach us.
I am happy to say that CFCs have been phased out and that since 2008 St. Lucia has ceased importation of goods which contain CFCs. In fact the use of CFCs has been banned in many countries throughout North America and the European Union. A prerequisite of the Montreal Protocol being that all CFCs should be phased out by 2010. The Montreal Protocol on Substances that Deplete the Ozone is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion.
However, the problems of ozone depletion persist. Currently used refrigerants, HCFCs for instance; which are a mixture of hydrogen, chlorine, fluorine and carbon, though having a shorter life when exposed to the atmosphere, resulting in less potential damage to the ozone, still cause environmental concerns if they leak into the atmosphere because they are considered greenhouse gases and may contribute to climate change.
The ozone has been depleted in many areas especially in the Antarctic since the mid-1980’s. This region’s low temperatures speed up the conversion of CFCs to chlorine which reacts with the ozone, destroying it. It is estimated that about 65% of ozone depletion has taken place over the Antarctic.
As world-wide controls reduce the release of CFCs and other ozone-eating substances, nature will repair the ozone layer. Thank God! It is expected that by the year 2065 stratospheric ozone should return to the amount that was present in 1980 when there was less depletion.
It is important that we protect ourselves from the ill effects of harmful ultraviolet rays especially between the peak hours of 10 am to 4pm when the sun’s intensity is at its highest.
Most of us melanin rich St. Lucians don’t think there’s need for protecting ourselves from the sun. That my friend is a misconception; though we may not burn as quickly as our fairer friends we are exposed to the same risk of getting skin cancer especially if we have sensitive skin.
So folks, wear your brimmed hats and sunshades, stay out of the sun especially at peak hours, wear your sunblock, SPF 15 or higher, cover yourselves from the sun’s harmful ultraviolet rays and don’t forget to buy ozone friendly products.
For further information please check out: http://ozone.unep.org/new_site/en/index.php