Air pollution
Air pollution is one of the main problems all over the world. Millions of chimneys, buses, cars, plants, factories and other industrial enterprises exhaust fumes and harmful substances into the atmosphere. Poisoned air is the main reason why it is hard to breathe in large cities with big amount of plants and transport (example Nijnij Tagil in the Urals).
Human activity has been increasing the concentration of such gases like carbon dioxide; methane, nitrous oxide-and water vapor in the atmosphere. Scientists expect to see a doubling of carbon dioxide over pre-industrial levels around the year 2065. Every year the atmosphere is polluted by about one thousand (1000) tons of industrial dust. Among industries especially toxic wastes are made by enterprises of colour metallurgy, chemical, petrochemical, black metallurgy, woodworking, pulp paper industry etc. Big cities suffer from smog.
Leaders of wastes of harmful substances in atmosphere in Russia during three last years are Krasnoyarsk region, the Tyumen, Sverdlovsk, Chelyabinsk, Kemerovo area and it is necessary to attribute this areas to a zone of the ecological catastrophe. The most contaminated regions are economic centers of Russian Federation and most populated. Now 2/3 population of Russia continues to live in conditions of dangerous air contamination. Various chemical elements are intensively absorbed by our organism during breathing, it is harmful for our health. Air pollution is especially harmful for quality of genofond.
Scientists say that air pollution is the cause of acid rains, global warming and of greenhouse effect.
Acid rains
First of all I should say that the only place on earth where pure water is found is in a laboratory. Rainwater always contains small amounts of impurities. These impurities come from dust particles or are absorbed from the gases in the air. If pure water is exposed to the air it absorbs carbon dioxide to form carbonic acid and becomes slightly acidic, dropping from pH 7 i.e. neutral, to pH 5,6. Even in remote, unpopulated areas rain can reach a pH of 4,5. However, a pH of less than 4, 5 in rain is almost certainly caused by air pollution.
Acid rain is caused by the release of the sulphur dioxide and nitrous oxides. The main sources of sulphur dioxide are coal-fired power stations and metal working industries.
The main sources of nitrous oxides emissions are vehicles and fuel combustion. Sulphurdioxide reacts with water vapor and sunlight to form sulphuric acid. Likewise nitrous oxides form nitric acid in the air. These reactions take hours, or even days, during which polluted air may move hundreds of kilometers. Thus acid rain can fall far from, the source of pollution.
When mist or fog droplets condense they will remove pollutants from the air andcan become more strongly acid than acid rain. Even snow can be acid. Gases and particles, not dissolved in water, with a low pH can also be deposited directly onto soil, grass and leaves. It impossible that even more acidity is deposited in this way than by rain! Not much is known about this process, and it is particularly difficult to study. There are some undoubted effects of acid rains:
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Acid rains can increase the acidity of lakes, dams and streams and cause the death of aquatic life.
Acid rain can increase the acidity of soil, water and shallow groundwater.
Acid rain has been linked with the death of trees in Europe and North America.
In spite of a great deal of research, no one yet knows exactly how acid rain
harms forests. Most of the forests of Europe consist of huge areas of one tree
species. This encourages the spread of plant pests and diseases. It seems likely
that acid rain weakens the trees, perhaps helped by other pollutants such as
ozone, and then leaves the trees open to attack by disease. Acid rain also
disrupts the availability of soil nutrients. The final death of a tree may result
from a combination of stresses such as heat, cold, drought, nutrient disruption
and disease.
Acid rains erode buildings and monuments.
Acid particles in the air are suspected of contributing to respiratory problems of people.
Scientists have many ways to solve this environmental problem. We need to use energy more efficiently at home, in ourvehicles and in industry. We will have to think hard about alternative energy sources. It is possible to remove acidic emissions from coal burning, but this is very expensive. It may be possible to breed crops and trees that resist pollution, but this would only be a partial solution. In practice we will probably need a combination of all these ideas and innovations.
Water pollution
Comprising over 70% of the Earth's surface, water is undoubtedly the most precious natural resource that exists on our planet. Without the seemingly invaluable compound comprised of hydrogen and oxygen, life on Earth would be non-existent: it is essential for everything on our planet to grow and prosper. Although we as humans recognize this fact, we disregard it by polluting our livers, lakes, and oceans. Subsequently, we are slowly but surely harming our planet to the point where organisms are dying at a very alarming rate. In addition to innocent organisms dying off, our drinking water has become greatly affected as is our ability to use water for recreational purposes. In order to combat water pollution, we must understand the problems and become part of the solution.
What are the sources of water pollution?
There are many causes for water pollution but two general categories exist, direct and indirect contaminant sources.
Direct sources include effluent outfalls from factories, refineries, waste treatment plants etc. that emit fluids of varying quality directly into urban water supplies. In the United States and other countries, these practices are regulated, although this doesn't mean that pollutants can't be found in these waters.
Indirect sources include contaminants that enter the water supply from soils groundwater systems and from the atmosphere via rainwater. Soils and ground waters contain the residue of human agricultural practices and improperly disposed of industrial wastes. Atmospheric contaminants are also derived from human practices (such as gaseous emissions from automobiles, factories and even bakeries). Contaminants can be broadly classified into organic, inorganic, radioactive and acid. Examples from each class and their potential sources are too numerous to discuss here.
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What are the effects of water pollution?
The effects of water pollution are varied. They include poisonous drinking water, poisonous food animals (due to these organisms having bioaccumulated toxins from the environment over their life spans), unbalanced river and lake ecosystems that can no longer support full biological diversity, deforestation from acid rain, and many other effects. These effects are, of course, specific to the various contaminants.
| The problem | What causes it? | How can it be solved? |
3. Imagine that you are a group of journalists writing an article to a magazine Ecology on your problem.
4. Decide what will be in your article, how will you organize it, will you put pictures (photos) and so on.
5. Design and write an article. There will be 3 main parts:
1. Introduction to the problem.
2. Main part (description of your problem and the ways of solving).
3. Conclusion.
