تلوث الهواء - بحث عن تلوث الهواء بالإنجليزي - Air Pollution - free essay
للتحميل في المرفقات آخر الموضوع او نسخ الموضوع مباشره
Air pollution Introduction With the great concern surrounding the destruction of the earth’s atmosphere due to air pollution, the immediate and direct harm caused to the human body is often over shadowed. While many are aware that our careless use of hazardous chemicals and fossil fuels may leave the planet uninhabitable in the future, most over look the fact that they are also cause real damage to our bodies at this moment. Such pollutants cause damage to our respiratory system, leading to the fluctuation of the life span of an individual depending on a number of conditions. Amongst these conditions are the individuals specific geographic ********, age, and life style. This paper is structured as a series of relevant questions and answers to report on the description of these pollutants there affects on our bodies. What are the pollutants? And how do they affect our bodies? In order to understand how air pollution affects our body, you must under stand exactly what this pollution is. The pollutants that harm our respiratory system are known as particulates. Particulates are the small solid particles that you can see through a ray of sunlight. They are products of incomplete combustion in engines (example: automobile engines), road dust, and wood smoke. Billions of tons of coal and oil are consumed around the world every year. When these fuels burn they produce smoke and other by-products into the atmosphere. Although wind and rain occasionally wash away the smoke given off by power plants and automobiles, much still remains. Particulate matter (soot, ash, and other solids), usually consist of unburned hydrocarbons, carbon monoxide, sulfur dioxide, various nitrogen oxides, ozone, and lead. These compounds undergo a series of chemical reactions in the presence of sunlight, the result is smog (a term used to describe a noxious mixture of fog and smoke) The smog in this photograph of Beijing, China is so dense that you can barely see the mountains The process by which these pollutants harm our bodies begins by simply taking a breath. Particulates are present every where, in some areas they are as dense as 100,000 per milliliter of air. The damage begins when the particulates are inhaled into the small air sacs of our lungs called alveoli. With densities such as 100,000 per milliliter a single alveolus may receive 1,500 particulates per day. These particulates cause the inflammation of the alveoli. The inflammation causes the body to produce agents in the blood that in crease clotting ability, which leads to the decreased functionality of the cardiovascular system, resulting in diseases and increased mortality. In the blood, carbon monoxide interferes with the supply of oxygen to all tissues and organs, including the brain and heart. Particulates accumulate on the mucous linings of the airways and lungs and impair their functioning. Continued exposure to particulates damages the lungs and increases an individual's chances of developing such conditions as chronic bronchitis and emphysema. Inside the alveoli of the lungs, particulate air pollution irritates and inflames them. While you may see pollutants such as particulates, other harmful ones are not visible. Amongst the most dangerous to our health are Carbon Monoxide, Nitrogen Oxides, Sulfur dioxide, and Ozone. If you have ever been in an enclosed parking garage or a tunnel and felt dizzy or light-headed then you have felt the effect of carbon monoxide(CO). This odorless, colorless, but poisonous gas is produced by the incomplete burning of fossil fuels, like gasoline or diesel fuel. Carbon Monoxide comes from cars, trucks, gas furnaces and stoves, and some industrial processes. CO is also a toxin in cigarettes. Carbon Monoxide combines with hemoglobin in the red blood cells, so body cells and tissues cannot get the oxygen they need. Carbon Monoxide attacks the immune system, especially affecting anyone with heart disease, anemia, and emphysema and other lung diseases. Even when at low concentrations CO affects mental function, vision, and *****ness. Nitrogen Oxide is another pollutant that has been nicknamed a jet-age pollutant because it is only apparent in highly advanced countries. Sources of this are fuel plant, cars, and trucks. At lower concentrations nitrogen oxides are a light brown gas. In high concentrations they are major sources of haze and smog. They also combine with other compounds to help form ozone. Nitrogen Oxides cause eye and lung irritation, and lowers the resistance to respiratory illness, such as chest colds, bronchitis, and influenza. For children and people with asthma, this gas is can cause death. Nitrogen Oxides maybe the most dangerous of these pollutants because it also makes nitric acid, when combine with water in rain, snow, fog, or mist. This then becomes the harmful acid rain. Sulfur Dioxide is a heavy, smelly, colorless gas which comes from industrial plants, petroleum refineries, paper mills, and chemical plants. When combined with water it becomes sulfuric acid. Sulfuric acid dissolves marble, turns plants yellow, and eats away at iron and steel, you can imagine the possible damage to human tissue. It’s effect on people with asthma, heart disease, and emphysema is devastating. It is also a major contribute to acid rain. How serious of a thereat is it to our health? There are numerous cases displaying the grave danger of particulate air pollution. One popular example occurred in London, England in the year 1952. In this case excessive deaths were caused as a result of respiratory and cardiovascular problems in that year. The research at that time revealed an association between particulate and sulphur dioxide concentrations in the air and risk of respiratory disease and death. The excessive problems are thought to have been caused by winter smogs. Winter smogs were frequent problem during the 1940s through the 1950s when coal was the main fuel for both domestic and commercial use. Winter smogs are caused by temperature inversions which trap particulates close to the ground. The air and smoke trapped contained high concentrations of soot, sulphur dioxide, and other pollutants. This winter smog took the lives of over 3,500 people. A similar incident in the United States came about as a result of the same type of temperature changes and smog. In 1948 six thousand people became drastically ill and twenty died as a direct result of winter smog in Pennsylvania. More recently an even greater tragedy occurred. One of the great human and environmental disasters of the 1980s occurred on December 3, 1984, in Bhopal, India. About 50 tons of methyl isocyanate escaped into the air from a pesticide company owned by the American corporation Union Carbide. Estimates of the death toll in surrounding neighborhoods were as high as 2,500. About 100,000 others were injured by the gas leak. Who is at the greatest risk? Since the in industrial revolution city dwellers have always been exposed to higher levels of particulate air pollution. As I have mentioned, the fuels use in the urban factories release large amounts of pollutants such as sulfur dioxide and soot. Another main factor is the heavy use if motor vehicles by the city population. In the city, where many people and objects occupy a small area the problem is amplified. Depending on the weather conditions the threat can become even greater. Another major factor is the individual. While sex does not matter age and health history do. It has been proven that death or illness from air pollution is more likely in young people, old people, and people that smoke. Children are often more vulnerable to those pollutants for two main reasons. The first being that because of their small size their heartbeats and ****bolic rates are faster. Therefore all reactions within their bodies including the harmful ones of pollutants (chiefly the replacement of oxygen with carbon monoxide in the blood stream) take place at an accelerated pace. The second is the relatively weak immune systems of young children. Particulates that act as irritants take a greater toll on their still developing bodies. The same threats that air pollution pose to young people effect older members of society. Although their ****bolic rates not high, their immune systems maybe equally as weak. An investigation conducted by the Helen Dwight Reid Educational Foundation on the joint effects of air pollution and smoking showed that smokers in Beijing, China suffered from greater problems in their pulmonary artery functions. They also had a vital lung capacity decrease of over 10%. Conclusion It is apparent that our careless use of fossil fuels and chemicals is destroying this planet. And it is now more than ever apparent that at the same time we are destroying our bodies, proving that our pollution is not just a problem that we can pass on to our children.