Monday September 16^th has been designated World Ozone Day by the United Nations, with the goal of continuing the awareness and monitoring of the condition of the ozone layer surrounding the Earth. Several years ago, the was a great amount of news coverage about the discovery and subsequent widening of several “ozone holes” around the globe. At the time, you couldn’t turn on to any news station and not hear some new bulletin expressing the growing concern of environmentalists about the effects this occurrence would have on the global ecosystem. However, more recent events soon supplanted these stories, and it became almost a case of ‘out of sight, out of mind’ for the average person. Unfortunately, this is a problem that has not (and will not) just go away on its own, and the public must continue to be alerted to the dangers posed by the depletion of the ozone layer.

WHAT IS OZONE?

            So what exactly is ozone anyway? Well, ozone is a chemical molecule made up something we have all heard about- oxygen. Discovered in 1840 by German chemist Christian Schönbein, ozone is made up of three oxygen atoms (O₃- what we breathe has only two (O₂)). It is formed mainly by the action of ultraviolet (UV) rays from the sun on breathable oxygen in the atmosphere, although it may also be formed by lightning during rainstorms. Most of the ozone in the atmosphere is concentrated in a thin layer some 24-30 kilometres (15-20 miles) above the ground. Now, on to the important part- what is the big deal about ozone? This simple molecule’s pivotal role is to act as a sort of sunscreen for the planet, absorbing UV radiation from the sun, a job which it performs with great efficiency: up to 99% of the UV light from the Sun which enters Earth’s atmosphere does not go beyond this layer. Therefore all life on the planet is spared the effects of this radiation, which has been linked to skin cancer and eye damage in humans, reduced crop yields in agriculture, along with disruption of marine and freshwater environments. When the ozone molecule absorbs this radiation it is broken down, and the components can then later reform new ozone molecules. (Incidentally, this vital ozone is actually dangerous if inhaled!)

WHAT’S THE PROBLEM?

            If ozone molecules are constantly being destroyed and subsequently reformed, some of you may ask, “well, what’s the problem?”. Put simply, we are. As our civilization becomes more industrialized, we produce a lot of waste and new, dangerous chemicals which do not naturally exist. Some of these chemicals are in the form of gases, which make their way upward to the ozone layer. There, they also cause the breakdown of ozone, but do not help to reconstitute the molecule (some in fact also prevent this from happening by the natural method). Even worse, these chemicals destroy ozone faster than it can be remade naturally. One group of chemicals known as CFCs (the most notorious of the ‘ozone depleters’) is an example- one CFC molecule can destroy up to a million ozone molecules before it is itself destroyed. CFCs can be found as the propellant in some spray cans and asthma inhalers, in the coolants used in air conditioners and fridges, and may also be released by the burning of materials such as Styrofoam.

WHAT CAN BE DONE?

            In 1978, the first international accord regulating the use of these ozone depleting chemicals was signed in Montreal, Canada. This treaty (and subsequent others) aimed to reduce or eliminate the production and use of CFCs in particular by 2000. This has been mostly successfully among developed countries, but industries in developing nations may not be subject to these regulations.

            Despite these positive actions, scientists do not predict a recovery for the ozone layer until around 2050. This is because even with the reduction in CFC emissions, there is still a large pool of these chemicals that have not yet reached the height of the ozone layer to damage it. In this aspect, very little can be done to stop what is already on its way up. In addition, these chemicals continue to be produced and released by industries around the world, some of whom cite the cost of switching to alternatives as the keep back. So what can we as consumers do to help? We can simply be more careful. Take the time to look to see if the spray products you buy have an ‘ozone-friendly’ or ‘CFC free’ label or statement. If you are asthmatic, ask your doctor about the availability of new propellants that do not contribute to ozone damage. When changing the coolant in your car or home air conditioner or refrigerator, go to a reputable dealer who supplies ozone safe products. These simple measures do not cost anything more, but can go a long way in ensuring that we minimize any future destruction of our precious ozone layer.

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Last modified: December 29, 2002