Реферат: Enviormental Concerns The Depletion Of The Ozone

Enviormental Concerns: The Depletion Of The Ozone Layer Essay, Research Paper

Environmental Concerns:

The Ozone Layer

By David Wood

Everyday millions of people are exposed to an invisible danger. An unseen danger that can cause horrible and drastic effects. Something so horrible that without prevention could lead to a horrible future. This danger is the depleting of the Ozone Layer. As it gets thinner and thinner more and more harmful UV rays will pass into our atmosphere. These UV Rays are the leading cause in many different diseases known today, with Melanoma, Skin Disease, and Cancer being the most prominent.

The Ozone Layer is a layer of gas, which is found high in the Earth?s stratosphere. Ozone (O3) is a form of oxygen. It is a colorless gas that has a very strong odor. It exists in low concentrations in the stratosphere where it absorbs ultraviolet radiation. In the troposphere, the earth?s lowest region of the atmosphere, ozone exists naturally at extremely low quantities. But these concentrations increase when sunlight acts on various gases, such as those coming from mainly vehicle exhausts, causing ozone to then become a pollutant in the troposphere. Ozone is a highly corrosive gas and is poisonous to most organisms. At concentrations as low as 0.00001 per cent (or 10 parts per hundred million) it can irritate the membranes lining the nose, throat and airways and can trigger or excel asthma attacks.

Ozone gas forms a layer around the earth high in the stratosphere. It serves as a vital protective barrier from the sun’s ultraviolet rays. In recent years, scientists have sounded alarms internationally about the depletion of the ozone layer, citing chemical pollution as the major cause.

A specific type of chemical compound called chlorofluorocarbons, or CFCs, are most often identified as ozone destroyers. CFCs were commonly used in everything from air conditioner coolants to the propellants in aerosol cans. Most manufacturers are now using substitutes for CFCs.

Many scientists believe that unless steps are taken to protect the ozone layer there will be increased levels of ultraviolet radiation. With the increase in radiation there may also be an increase in human health hazards. The added exposure to sunlight may result in an increase in the incidence of skin cancer and eye damage. Some studies have suggested that plant life may also be affected, reducing world food supplies.

There have been many international initiatives to protect the ozone layer. One of these initiatives came in the form of The Montreal Protocol, which was signed by many countries pledging to help control the production and use of CFCs. In the United States, the Federal Clean Air Act Amendments of 1990 addressed the issue of ozone depletion. With these efforts such as there other organizations worldwide, we will be seeing that ozone depleting products will no longer be manufactured. Refrigerants from motor vehicles and air conditioners have been recycled since 1992. Individual countries are working with manufacturers to discontinue use of these pollutants.

Ozone pollution is really an increase in the concentration of ozone in the air at ground level. The greatest concern about ozone pollution is the potential damage it may inflict on human health. High concentrations of ozone are especially hazardous to children, the elderly, and people with respiratory problems. Each year food crops are damaged by ozone. Chemists claim that ozone damages rubber, nylon, plastics, dyes, and paints.

Because sunlight has a critical role in its formation, ozone pollution is principally a daytime problem in the summer months. The presence of hydrocarbons and nitrogen oxide in sunlight with little air movement leads to the generation of ozone. These two compounds are produced by cars, trucks, factories, and power-generating plants or wherever gasoline, diesel fuel, kerosene, oil, and natural gas are burnt or used. Urban areas with heavy traffic and large industrialized communities experience the most ozone problems.

When temperatures are high and there is little wind, the ozone produced can reach dangerous levels. Weathermen can predict when an area will be subject to an ozone alert. When an ozone advisory is issued for an area, people at risk should take simple precautions like staying indoors. Using public transportation or car-pooling is helpful in reducing the high concentrations of pollutants that contribute to the formation of ozone at ground level. Even avoiding the use of a gasoline-powered lawnmower is helpful when an ozone advisory is in effect.

Much concern over the impacts of increased ultraviolet radiation exposure to human health has caused governments around the world to establish daily warning programs. In Australia, Austria, Canada, Germany, Great Britain, New Zealand, Netherlands, and the United States, forecasts for the level of solar ultraviolet radiation and sunburn times are posted throughout newspaper, radio and television messages. In Holland, the Dutch authorities conduct an annual skin cancer awareness campaign, which includes the providing of free sunscreen to people working outdoors.

In Canada there is an UV Index, or a forecast of the time required for fair, unprotected skin to burn under the highest sun based on the thickness of the ozone layer above and the time of year. It is provided to all forms of media daily to keep citizens knowledgeable. In some newspapers, it is front-page information. The commercial television weather service, or The Weather Network, on many US cable networks, provides a feature on the Index and actual UV measurements twice hourly during most of the year. In Australia messages like their “Slip, Slap, Slop” campaign urge citizens to slip on a shirt, slap on a hat and slop on sunscreen for protection. Public information campaigns by governments and public health organizations provide added information on the hazards of sun exposure.

Another way UV protection is taking affect, is in the alterations of school programs and other outdoor activities. These are focused on reducing sun exposure for children. In many cases teams of doctors specializing in skin cancers can be found on public beaches to educate sunbathers as to the dangers of excessive sun. General advice is for people to avoid exposure to direct sunlight between 11 AM and 4 PM. While programs to educate and alert the public are absolutely necessary, they are expensive, and in most countries, draw upon already scarce resources. Some countries, especially developing nations, simply don’t have the resources to protect the public through high profile public information campaigns. Most people?s lives will be negatively affected by the impacts of increased UV-B radiation. Poor countries will suffer to an even greater extent.

All of these, along with many other factors, are why we need to start being more aware of our environment, and start taking care of where we live. If we don?t start trying today, there might not be anything to even worry about sometime soon.