Автор: Пользователь скрыл имя, 16 Февраля 2013 в 18:07, реферат
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light.
1. Types of pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light.
Pollution is a major problem all around the world. It has adversely affected the lives of millions of people and caused many deaths and health disorders. Pollution is contamination by a chemical or other agent that renders part of the environment unfit for intended or desired use. Natural processes have released toxic chemicals into the environment throughout the history of the earth. Currently, the pollution generated by human activities presents the most serious problem.
There are basically 3 types of pollution. They are:
1) Air pollution;
2) Water pollution;
3) Land pollution;
Some of the major causes of the pollution crisis are as follows:
I) Deforestation - for the establishment of factories, industries and due to urbanization in various parts of the world, trees are cut on a large scale without any adequate efforts to plant new trees. This leads to deforestation, which has caused a rise in the pollution levels and distortion of natural order.
II) Polluted rivers - The wastewater and liquids from plants and factories are linked with nearby river water, which are polluted when they release disposal from these units. People in Developing/Undeveloped countries also pollute rivers by using the water in these rivers for washing clothes, utensils, bathing and other activities. Oil spilled from ships pollute oceans around the world.
III) Sound pollution - the machines used in factories make noise throughout the day, and this disturbs the peaceful atmosphere in the vicinity, as machines used without proper covering lead to sound pollution. It puts heavy mental strain on the people staying in the nearby areas. Noise is the most pervasive pollution in America.
IV) Air Pollution - each year industrially developed countries generate billions of tons of pollutants. Many pollutants come from directly identifiable sources; sulphur dioxide, for example, comes from electric power plants burning coal or oil. Others are formed through the action of sunlight on previously emitted reactive materials (called precursors). For example, ozone, a dangerous pollutant in smog, is produced by the interaction of hydrocarbons and nitrogen oxides under the influence of sunlight. Ozone has also caused serious crop damage. The increasing of number vehicles have also lead to an increase in air pollution, due to the harmful gases like Carbon Monoxide emitted from these vehicles. Gases generated in the chemical plants also cause air pollution. People suffer because of smoke and bad smell from the industrial units particularly from chemical plants.
V) Soil pollution - dumping of wastes in many areas is a major cause of soil pollution. Also, when soil in and near production areas becomes dirty due to disposal of waste material, such land cannot be used for agricultural operations.
Pollution is also caused by iron and steel mills; zinc, lead, and copper smelters; municipal incinerators; oil refineries; cement plants; and nitric and sulphuric acid plants.
VI) Radioactive pollution, resulting from 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment;
VII) Thermal pollution, is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant;
IX) Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.
Pollution is also caused by iron and steel mills; zinc, lead, and copper smelters, municipal incinerators, oil refineries, cement plants , nitric and sulphuric acid plants.
The greenhouse effect is becoming more and more widely researched and acknowledged in the mainstream press. The simple explanation of the greenhouse effect is as follows: the burning of fossil fuels releases "greenhouse gasses" into the atmosphere.
These gasses do not dissipate over time, but remained trapped in the earth's atmosphere, absorbing heat from the sun. And according to the "One Hundred Months Project", launched in August of 2008, we may no longer have much chance to save ourselves.
The idea behind “The One Hundred Months project” is to teach the public that the "tipping point" in terms of the greenhouse effect is about to be reached. As of August 2008, we have one hundred months before the greenhouse effect becomes irreversible. Even if we stop all fossil fuel production at that point, the climate won't return to safe pre-industrial levels. The earth will continue to get hotter and deadlier until like the firewood it combusts, in terms of human life.
There is no shortage of effects out there from pollution that we all need to be aware of. The effects cause harm to humans, pets, plants, trees, and aquatic life. All living things are adversely effected by pollution.
Of the suite of pollutants that taint urban air, fine suspended particulate matter, sulphur dioxide (SO2), and ozone pose the most widespread and acute risks; however, airborne lead pollution is a critical concern in many cities as well. Recent studies on the effects of chronic exposure to air pollution have singled out particulate matter as the pollutant most responsible for the life-shortening effect of unhealthy air, although other pollutants may also play an important role. These pollutants cause respiratory and other health disorders.
Adverse air quality can kill many organisms including humans. Ozone pollution can cause respiratory disease, cardiovascular disease, throat inflammation, chest pain, and congestion. Water pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. In India, air pollution is believed to cause 527,700 fatalities a year. Studies have estimated that the number of people killed annually in the US could be over 50,000.
Oil spills can cause skin irritations and rashes. Noise pollution induces hearing loss, high blood pressure, stress, and sleep disturbance. Mercury has been linked to developmental deficits in children and neurologic symptoms. Older people are majorly exposed to diseases induced by air pollution. Those with heart or lung disorders are under additional risk. Children and infants are also at serious risk. Lead and other heavy metals have been shown to cause neurological problems.
And humans and animals can suffer from various health problems including viruses, cancer, and deformities due to the effects of pollution. Many birth defects are believed to be the result of pollution and the mother being exposed to forms of contamination during the development of the fetus. This can also occur for the young of animals in the wild even though it isn't as widely spreaded.
Air
Pollutant |
Health Effect |
Environmental Effect |
Carbon Monoxide |
Reduces ability of blood to bring oxygen to body cells and tissues; cells and tissues need oxygen to work. Carbon monoxide may be particularly hazardous to people who have heart or circulatory (blood vessel) problems and people who have damaged lungs or breathing passages |
|
Lead |
Brain and other nervous system damage; children are at special risk. Some lead-containing chemicals cause cancer in animals. Lead causes digestive and other health problems. |
Lead can harm wildlife |
Ground Level Ozone |
Breathing problems, reduced lung function, asthma, irritates eyes, stuffy nose, reduced resistance to colds and other infections, may speed up aging of lung tissue |
Ozone can damage plants and trees; smog can cause reduced visibility |
Nitrogen Oxides (NOx) |
Lung damage, illnesses of breathing passages and lungs (respiratory system) |
Nitrogen dioxide is an ingredient of acid rain (acid aerosols), which can damage trees and lakes. Acid aerosols can reduce visibility. |
Particulate Matter |
Nose and throat irritation, lung damage, bronchitis, early death |
Particulates are the main source of haze that reduces visibility |
Sulfur Oxides (SOx) |
Breathing problems, may cause permanent damage to lungs |
SO2 is an ingredient in acid cause permanent damage rain (acid aerosols), which can to lungs damage trees and lakes. Acid aerosols can also reduce visibility. |
Volatile Organic Compounds (VOCs) |
In addition to ozone (smog) effects, many VOCs can cause serious health problems such as cancer and other effects. |
In addition to ozone (smog) effects, some VOCs such as formaldehyde and ethylene may harm plants. |
Water
Pollutant |
Health Effect |
Contaminated Sediment |
Metals, PAHs, and organics listed above are toxic to various plants and animals, including people. These contaminants tend to biomagnify as they travel up the food chain. All have been linked to health problems in people. |
Disinfection By products |
Acute and chronic gastrointestinal illness, cancer, liver toxicity, and reproductive and developmental disorders |
Dredged Materials |
Acute and chronic gastrointestinal illness, cancer, liver toxicity, and reproductive and developmental disorders |
Microbial Pathogens |
Acute and chronic gastrointestinal illness, cancer, liver toxicity, and reproductive and developmental disorders |
Land
Pollutant |
Health Effect |
Arsenic |
Skin damage; circulatory system problems; increased risk of cancer |
Barium |
Increase in blood pressure |
Benzene |
Anemia; decrease in blood platelets; increased risk of cancer |
Cadmium |
Kidney damage |
Cyanide |
Nerve damage or thyroid problems |
Lead |
Infants and children: Delays in physical or mental development. Adults: Kidney problems; high blood pressure |
Mercury |
Kidney damage |
Polychlorinated Biphenyls (PCBs) |
Skin changes; thymus gland problems; immune deficiencies; reproductive or nervous system difficulties; increased risk of cancer |
Toluene |
Nervous system, kidney, or liver problems |
Trichloroethylene (TCE) |
Liver problems; increased risk of cancer |
Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution control, the waste products from consumption, heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade the environment. A variety of approaches have been developed to manage existing pollution. These include punishment of polluters through regulation, taxation, fines, toxic tort suits, and other disincentives; encouragement of nonpolluting approaches through tax and other incentives; and education of the public. The increased awareness of the potential harmful effects of pollution has had a major impact on industries and on individuals, particularly the young, who have led the way in activities such as recycling. Risk assessment has developed as a useful technique to estimate the risks of environmental pollutants and to establish priorities for environmental control and remediation efforts. These efforts to manage existing pollution are largely a form of secondary prevention in that the pollution already exists and the focus is on lessening the extent or the effects.
So our government and others should think seriously about the issue of environmental pollution and begin to act or it may have an adverse effect on our future generations.
References
1. http://www.answers.com/
2. http://www.essortment.com/
3. http://reducepollutiontip.com/
4.http://en.wikipedia.org/
Our nature is beautiful!
Nitrogen pollution - the result of vehicles
Our life in our hands!