The earth is wrapped in layers of air called the atmosphere. The sun gives off light, heat, and other types of radiation. Too much UV ultraviolet radiation can cause skin cancer, cataracts, and harm plants and animals. Instead, the protective layer contains less ozone than it used to. This thinning is found all over the earth, but the biggest losses are over the North and South Poles. You can see current levels of ozone over the South Pole at ozonewatch. The trouble with ozone destruction starts when certain chemicals used in air conditioners, fire extinguishers, insulating foams, and solvents are let out during use.
Ozone in swimming pool water. Ozone in drinking water. Ozone in cooling towers. Ozone in industrial laundries. Toggle navigation. Home Library Ozone. About Lenntech. General Delivery Conditions. Privacy Policy. All rights reserved. The polar vortex exists only over Antarctica, which is why the ozone "hole" exists only there. But the bigger the hole gets, the thinner the ozone layer will become over the rest of the Earth. This means more dangerous UV radiation will reach the Earth's surface.
An obvious solution, then, would be to pump more ozone up there to try to counteract the thinning. But creating an ozone patch is not a simple proposition. If we could patch the hole over Antarctica, the natural ozone-oxygen cycle might fall back into balance. But unfortunately, we can't make more ozone to patch the hole. It takes a lot of energy to make ozone molecules -- in the atmosphere, the intense energy of the sun drives most of the work.
But down at ground level, it's not a practical proposition. Plus, ozone is such a dangerous pollutant at ground level, it might not be wise to produce it even if it were easier to do. To repair the ozone layer, then, we must stop releasing ozone-depleting compounds into the atmosphere. In , more than countries agreed to address the problem in the Montreal Protocol.
In signing the protocol, those countries agreed to phase out ozone-depleting chemicals like CFCs, halons and carbon tetrachloride. In the United States, any products containing these compounds carry warning labels, and they can only be used if there is no suitable, non-ozone-depleting product available. Scientists hope that, if these compounds are completely discontinued, the ozone layer will return to normal by [source: EPA ].
In the meantime, wear sunscreen, immediately repair leaky cooling appliances, and be sure to only use HVAC repair services that are certified to properly deal with the refrigerant they remove. For more information on the ozone hole, CFCs and related topics, look over the links on the next page. When countries began phasing out ozone-depleting CFCs, they came up with a replacement known as the HFC, or hydrofluorocarbon. For several months each year, much of the protective layer of stratospheric ozone above Antarctica disappears, creating what is popularly known as the ozone hole.
With less ozone in the atmosphere, more ultraviolet radiation strikes Earth. This harmful radiation can cause skin cancer, injure eyes, harm the immune system, and upset the balance of an entire ecosystem. Researchers have determined that chlorofluorocarbons CFCs have contributed to the depletion of ozone. CFCs are the human-made chemicals widely used in spray cans, foam packaging, and refrigeration materials.
Chemically inert, CFCs accumulate in the atmosphere over time until they eventually drift to the upper atmosphere, where they encounter high energy UV radiation. Many countries have agreed to phase out the use of these ozone-destroying chemicals, thus giving the hole a chance to heal itself.
The EPA has great resources on ozone layer depletion, with sections on what we can each do to reduce the release of CFC's. This in-depth article provides a detailed explanation of the causes and impacts of ozone depletion.
0コメント