The elements of the air in which we breathe in is determined by a delicate balance in nature. Process such as photosynthesis, respiration, combustion and decay play an important role on maintaining this balance.
Many of our activities
° increase amount of the carbon (IV) oxide in air:
° Introduce undesirable substances known as pollutants into the air.
When limits , the natural processes can remove the pollutants. Over the last few decades. Meanwhile, individualization has caused a extremely large increase in the release of pollutants into the air. In some areas , these pollutants are present in concentrations that cause harm to human, animal and plant life, and to property (the non living environment). Such a change in the air, where it is made impure , is known as air pollution.
CAUSES OF AIR POLLUTION
The main causes of air pollution is the combustion of fossil fuels such as coal, petrol, gasoline and gases.
However, Most of this factories, power plants and even vehicles such as motor cars, trains and air Craft makes use of fossil fuels to obtain energy. In the process, many pollutants are been released into the air.
meanwhile the causes of pollution include the release of freons from aerosol cans and also poisonous gases from chemical warfare.
The main air pollutants are as follows:
• Particulate matter(tiny solids),
•Oxides of carbon,
•Oxides of sulphur and nitrogen,
•Gaseous hydrocarbons and chlorofluoro_ carbons.
Smoke, soot and dust are emitted mainly by industrial processes and the burning of coal and wood fires. However note that they damage the respiratory system, especially the lungs. Another very poisonous solid pollutant is lead (and lead (II) bromide) which is emitted In the exhaust of motorcars using leaded petrol. Leas dust can cause leas poisoning and injury to the nervous system
The lead that is inhaled accumulates in the body. Over a long period, the amount of accumulated lead reaches levels that are toxic to the body.
SMOG: Usually the air next to the earth’s surface is the warmest. As it rises,it cools. Sometimes, a temperature inversion occurs and we get a warm layer of air above the earth’s surface. When this happens , pollutants become trapped underneath. Meanwhile, this can also result to the formation of smog . The Smog normally occurs when cities burn a lot of coal.
Smog reduces visibility and causes respiratory diseases. In severe cases, many deaths occur.
OXIDES OF CARBON
Carbon (II) oxide is a colourless, odourless and poisonous gas. It is produced in large amounts when the carbon in fuel is burnt incompletely.
Motor vehicles are the largest single course of carbon II oxide emission. Which when inhales ,competes with oxygen for the haemoglobin in the blood. Note, that it also causes a reduction in the quantity of oxygen that is carried to the body tissues.
A carbon (II) oxide concentration of 0.005%, in the atmosphere could, over prolonged periods, cause brain damage. At lower concentrations, carbon II oxide causes dizziness, headaches , fatigue and lethargy. However, Carbon (IV) oxide is been produced by many processes which makes use of fossil fuel as a source of energy. This excessive production of the gas, together with deforestation, has caused an increase in the level of atmospheric carbon (IV oxide.) Carbon IV oxide helps to retain a certain amount of the infrared ray (,heat ray) that is radiated by earth .An increase in the level of atmospheric carbon IV oxide would result in a greater retention of infrared ray, giving rise to the greenhouse effect _ a gradual warming of our planet. Such an occurrence would cause the polar caps to melt and submerge many of the coastal regions and islands on earth.
OXIDES OF NITROGEN AND SULPHUR
Oxides of sulphur are acidic, corrosive and poisonous. When sulphur containing coal is burnt. It gives off sulphur IV oxide . Most of the sulphur IV oxide comes from electric power stations and industrial plants.
Oxides of nitrogen are produced when combustion of fuels occurs at high temperatures . The major sources of pollutants (eg NO, NO2) are from the exhaust of transportation vehicles. Oxides of sulphur and nitrogen dissolve in rain water to produce acids. This results in the fall of acid rain which is harmful to plant and animal life, buildings and metal structures.
Oxides of nitrogen react with sunlight to produce secondary pollutants such as ozone, nitrogen IV oxide and alkanals. These, together with the solid pollutants and water droplets in air, form the constituents of smog. The oxides of nitrogen and sulphur cause irrational of the eyes, nose, throat and respiratory tissues.
hydrocarbons are released into the air when fuels evaporate from storage tanks. Note, that they are also found in the exhaust of motor vehicles when fuel is been burnt incompletely. Many hydrocarbons are believed to cause cancer. However, ‘reacting’ with the nitrogen oxides in the presence of light, they tend to produce smog or even heavily stagnant air.
chlorofluorocarbons or CFCs are a group of man made chemicals such as freon which are used as propellants for spray cans, coolants in refrigerators and air conditioners, and for making plastic foams. But, In the atmosphere, remember, that the ultra violet light breaks off a free chlorine atom as well. CL, from a chlorofluorocarbon molecule. The free chlorine atom is very reactive and attacks a molecule of ozone, O3, to produce an ordinary oxygen molecule, O2, and an unstable oxide of chlorine, CLO. The latter readily reacts with atomic oxygen, O,(usually present in this layer of the atmosphere) to form an oxygen molecule, O2 and release the chlorine atom, which then attacks another ozone molecule. Thus, the process is repeated numerous times, causing a depletion in the ozone layer. Note that the ozone layer can be found in the stratosphere. Data from satellites show a definite drop in ozone levels and revealed an ‘ozone hole’ over the Antarctic. The ozone layer is important because it acts as a shield preventing too much ultraviolet light from reaching the earth’s surface. A diminishing ozone layer means an increase in the level of ultra violet radiation that reaches earth. This poses a danger to human health and may cause an increase in cataracts, skin cancer and sunburns. It may also damage our body’s defence system, thus lowering our resistance to diseases.
CONTROL OF AIR POLLUTION
1. Strict laws should be passed to make factories and users of motor vehicles keep air pollution down by using anti pollution devices and taking anti _pollution measures.
2. Machinery should be improved so that more efficient fuel combustion occurs.
3, People in our societies should be educated to make them aware of the causes and dangers of this pollution.
However the level of this air pollution has reached a critical point. But, there are still
Solutions in which we can minimize the number of air pollutants from the air.
Reforestation– we can improve the quality of air by planting more and more trees as they clean and filter the air.
Policy for industries- we need Strict policy for industries that is related to the filter of gases needs to be introduced in the countries. So, we can reduce this toxins released from al this factories.
The Use of eco-friendly fuel- We need to adopt the usage of the Eco-friendly fuels such as LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), bio-gas, and other eco-friendly fuels. So, we can minimize the amount of this harmful toxic gases.
Note, that the biggest contribution of the increase in air pollution is from fossil fuels which produce nitric and sulphuric oxides. However, we humans have taken this particular problem seriously and we are devotedly working hard to eradicate the problem that they have created.
Meanwhile the control policies and the methods is often extrapolated from the local to regional, then to the global scale as well. Note, that Air pollution can be dispersed and transported from one area to another region that is located far away. However, the Air pollution management means the reduction to acceptable levels or possible elimination of the air pollutants whose presence in the air affects our health or even the environmental ecosystem as well.