The air pollutants are broadly divided into the particles and gases. The particles can be solid or liquid. The gases are the substances which are in the gas form at the normal temperature and pressure. They have an adverse effect on the animals, plants and human beings.
They change the climate of earth and also affect the aesthetic sense. The particle matter can be suspended or be settled. The settle able particles are longer in the length and are more than 10 micrometer. The suspended particle is shorter than 10 micrometer in length. They are divided into the dust, aerosol and mist. The aerosols are less than 1 micrometer in the size. The dust is in solid state and is more than 1 micrometer in the size. The mist is in liquid state and is more than 1 micrometer in the size. These may lead to the dust and smoke particles. They cause irritation and respiratory problems. It is the most common problem in the Bhatinda area of Punjab. It has a thermal plant. The smog is also formed which is a combination of the smoke and fog. It is dark in color. In this there occurs a condensation of the water vapors. It also affects the plant life by the glazing and necrosis. It also affects the availability of light. It causes the respiratory troubles in human beings. It also causes the accidents as it leads to decrease in the visibility. A few thousand people were killed in the smog in London. It also caused illness and has an adverse effect on the plant life. The particle matter which is present in the air scatters and absorbs some light. In the urban and in industrial areas the sunlight is reduced to 33 percent in summer and 66 percent in the winter season. It has an adverse effect on the vehicles.
The volcano eruptions can lead to decrease in the transmission of solar radiations. This occurs due to the large quantities of the particles in the stratosphere. Some authors have suggested that the cotton dust less than 2mm has a concentration of around 200 mg/100 cubic meters. It is around 800 mg/100 cubic meters in ginning presses. This cotton dust can produce a condition known as the pneumoconiosis which is also known as the Lung fibrosis. These can occur in the other industries also like the asbestos, stone grinding and iron mills. These are referred as the asbestosis, silicosis and siderosis. The welders suffer from manganese poisoning. The Toxicology research centre in the Lucknow has given the reports about the lung fibrosis incidence in the different industries. The smog present over the plants affects the stomata and blocks them. They form the thin layers on leaves and decrease the absorption of light and the process of photosynthesis. The carbon monoxides accounts for nearly half of the air pollution. It is due to the incomplete combustion of the fuels in various industries. The plants and animals also produce carbon monoxide. The total production of carbon monoxide is 2.5 multiply by 10 raise to power 9 tones. The plants account for nearly 10 raise to power 8 tons of carbon monoxide. It has the ability to combine with the haemoglobin of blood and form carboxy haemoglobin. It affects the oxygen carrying ability of the blood. If its concentration increases around 100 ppm it leads to the headache, dizziness, laziness, exhaustion, impairment in the vision and motor functions. This may also lead to the death of an individual. A high concentration of carbon monoxide is seen in the traffic jams in the metropolitan cities. The sulphur oxides occur in the form of sulphur dioxide. The smelting ores, burning of coal and petroleum produces a large amount of sulphur dioxide. It is also released by the motor vehicles and thermal plants. It has the ability to react with water and to form a sulphurous acid. It can cause acid rain. The sulphur dioxide causes the necrosis and chlorosis of the vegetation. It destroys the lichen and mosses. The indicator of sulphur dioxide pollution is garden pea. The sulphur dioxide affects the growth, metabolic activities and the membranes of the organisms. They can cause corrosion of the metals like iron and zinc. It has mutagenic ability too. It affects the electrical and metal equipments. The destruction of chlorophyll leads to the chlorosis. The chlorophyll is converted into the phaeophytin. The leaves look like water soaked and affect the monocots commonly. So, it is difficult for the cereal crops, apples, forests to survive in the areas which have high concentration of the sulphur dioxide. If its concentration is more than 1 ppm it can affect the human beings also. It affects the eyes and respiratory tract. The higher death rate in the old people is related to the high concentration of sulphur dioxide. It was discovered by Hicky in the year 1971. Some authors like Brehm in the year 1976 suggested that the killing of fishes is related to the high concentration of sulphur dioxide. It also leads to the discoloration of buildings and painted surfaces. The deterioration of Taj Mahal of Agra is the most famous example. The nitrogen oxides are produced naturally with the help of biological and non biological activities. The nitrates, nitrites, storms and solar fares play an important role in the formation of nitrogen oxides. The industries, automobiles and nitrogen fertilizers are the good source of nitrogen oxides. They form a smog and PAN. They deteriorate the textiles and cause their fading. They also have a corrosive effect on metals as they require moisture to act. It has mutagenic ability too. It affects the eyes, blood vessels and respiratory tract. At high concentrations it also affects the liver and kidneys. They can also cause cancer. They also destroy the ozone layer present in the stratosphere. It also affects the plants by causing defoliation and necrosis. The carbon dioxide concentration has been increasing. Nearly 75 tons of carbon dioxide has been produced by the single flight of plane. It does not allow the infra red waves to pass through. The sunlight is allowed to fall on earth but the loss of heat is checked. It absorbs more and more infra red waves as its concentration increases. This may increase the temperature leading to the green house effect. This may lead to the melting of ice and increase in the sea level.
The refinement of aluminum and phosphate emits fluorides. It also liberates the minerals of fluorides. The fluoride in gaseous form causes chlorosis of the leaf, which is followed by the necrosis of leaves, it also involves the fruits. The maize is also involved in some cases. There is a volatile liquid known as phosgene which is poisonous. It is used in the dye industry to make organic compounds. There is another substance known as methyl isocyanate which is also poisonous. Both of these gases were involved in the Bhopal gas tragedy in 1984. It killed and injured thousands of people. The aerosols are released in the form of vapors and mist and act as chemicals. They are passed in the air and act as disinfectants. There are emissions of the jet plane which liberate the chlorofluorocarbons. These are widely used in the refrigerator and in plastic foams. There is a chemical known as the carbon tetra chloride which is used naturally as well as in the activities of human. A compound known as the polychlorinated biphenyl is released when the plastic is burned. They have the ability to move to the food chain and can aggregate in the bodies of animals and plants. It happens in the higher trophic levels. It involves the pectoral muscle of sea eagle and the fat of mother milk. The reproductive function of animal is affected and in humans they affect the liver, central nervous system and vision. The chlorofluorocarbons react with the ozone layer which is present in the stratosphere and helps in its elimination. It is also supported by the carbon tetrachloride.
There are the photochemical oxidants which are released in the environment as a natural gas. These are mainly the hydrocarbons and the products of incomplete combustion of organic fuels. They are also formed by the decomposed organic products. They also have the cancer causing ability and are referred as the carcinogens. They cause an adverse effect on the plants leading to the senescence. The hydrocarbons have the ability to react with the other oxides and form ozone, PAN, aldehydes and these reactions occur in the presence of sunlight. The ozone layer can be harmful as well as useful. The layer which is present near the surface of earth in the troposphere is hazardous. The layer which is present in the stratosphere filters the harmful rays and saves the human life. It discolors the textiles and hardens the rubber. It may injure the mucus membrane at a concentration less than 1 ppm. At a 0.02 ppm it can destroy the chlorenchyma cells and form necrotic areas. There is a direct relationship with the ozone concentration and the destruction of foliage. The common PAN is peroxy propionyl nitrate which is referred as a PPN and peroxy butyryl nitrate which is referred as a PBN. The air pollution is mainly composed of the PAN. They affect the eyes and cause respiratory problems. They affect the plants by involving the process of photosynthesis. Other processes which are affected by the PAN are respiration, activity of the enzyme and anabolic process. It affects the output of crop. The pollutants affect the parenchyma and differentiated tissues. They affect the leaves by glazing, banding, bronzing, necrosis and silvering. The aldehydes irritate the respiratory and gastro intestinal tract. The phenols cause an adverse effect on the kidneys, spleen and liver. The air pollution is mostly caused by the automobiles. It involves the carbon monoxide, lead, benzopyrene, nitrogen oxides and ammonia. It also involves some sulphur compounds. Around a thousand liters of petrol forms a three hundred twenty kilogram of carbon monoxide along with the thirty kilogram of organic vapors. It also involves around five kilograms of nitrogen oxides and two kilograms of aldheydes and sulphur compounds. The other pollutants which are mentioned above are also produced but are smaller in the quantity. The combustion of gasoline produces almost all the lead pollution. It contains the tetra methyl lead. It acts as an anti knocking agent. The lead occurs mainly in the form of dust and aerosols. The aerosols have the ability to pass into the blood via lungs. The lead content of the people living in Bombay is around 17 micro gram per 100 milliliter and it shows the toxic effect when its concentration is around 20 micro gram per 100 milliliter. The main people who receive the high lead content are the traffic policemen and shop keepers. They are passed into the food chain. There are pollens and microbes which occur in the air. They are produced in the large numbers in certain seasons. The microbes affect the clothes, crops and are pathogenic to humans, animals and plants. They also have the ability to cause an allergy infection. The most common allergy infection is known as the hay fever. These pollen grains belong to the different types of plants.
