Pollution in the Environment: Types and Causes

Pollution is the introduction of contaminants into the environment. It is cause mostly by human actions, but can also be a result of natural disasters. Pollution has harmful effect on living and non-living things in an environment, making it difficult to maintain life.
There are different types of pollution. The main ones are:
1. Air pollution
2. Water pollution
3. Land pollution
4. Noise pollution
Air pollution
Air pollution is the accumulation of pollutants into the atmosphere that have harmful effect on human life and other organism. Air pollution is mostly due to human activities but sometimes may be because of natural disasters such as volcanic eruptions.
Causes of air pollution:
The industrialization of society, urbanization and the introduction of motorized vehicles, are factors contributing toward the growing air pollution problem. Indeed, nowadays with the growth of the population, number of vehicles on the road has also increased. Thus, the two main sources of air pollution are transportation (automobiles) and fuel combustion in stationary sources, including residential, commercial, and industrial heating and cooling and coal-burning power plants. High levels of harmful gases such as carbon dioxide, carbon monoxide, nitrogen oxides, sulphur dioxides and many more are released by vehicles, industries or volcanoes.
Effect of air pollution:
1. Formation of smog in highly industrialized countries such as China. Smog leads to harmful health problems to senior citizens and children. It can inflame breathing passages, decrease the lungs' working capacity, cause shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and interferes with the body's ability to fight infection, increasing susceptibility to illness. Asthma and bronchitis.
2. Formation of acid rains. Sulfur dioxide or nitrogen oxides released, combined with oxygen and water -vapour in the atmosphere forming sulphuric acid or nitric acid. These acids dissolve in rain water resulting in acid rain which falls to Earth causing a disastrous effect to the environment and to people. Vegetation are destroyed as the soil is too acidic, all the nutrients in the soil are washed away, the land for agriculture become barren. Aquatic life is destroyed as the water is acidic. In addition, acid rain accelerates the decay of building materials, paints, statues, and sculptures. Acid rains have little impact on human but the pollutants responsible for its formation leads to respiratory disease and other illnesses. Acid rain's effects are destructive and long lasting.
3. Depletion of the ozone layer. The excessive use of CFCs in the past as aerosol propellants or as coolants in refrigerators and air conditioners, have destroyed the ozone layer by reacting with it in the higher atmosphere. The ozone layer protects Earth from harmful radiation from the sun. However, when the ozone layer is depleted, it results in an increased exposure to UV (ultraviolet) rays from the sun. In humans, this can cause diseases like skin cancer, eye damage. Plants are damages, decreasing crop productivity. It contributes also to global warming.
4. Greenhouse effect. The amount of carbon dioxide in the atmosphere has increased over the past years due to large amount of carbon dioxide released from the burning of fossil fuels (e.g. coal or oil) in factories and motor cars. The increased concentration of carbon dioxide together with other gas pollutants in the atmosphere form a layer over the Earth’s surface retaining the heat radiated from Earth and prevents much of it from escaping into space. Heat is therefore trapped causing the Earth temperature to rise that is greenhouse effect. The result may be global warming. The consequences of global warming:
• The world temperature may rise.
• Polar ice caps will melt if temperature keeps rising, thus, causing sea levels to rise flooding low-living land like the Maldives.
• Changes in global climate.
5. Released of carbon monoxide from incomplete combustion of fuel in motor vehicle engines or forest fire. Carbon monoxide can cause death. Haemoglobin, a red compound in the blood carries oxygen in the form of oxyhaemoglobin and release the oxygen in every parts of the body where it is needed. But when carbon monoxide is inhaled, haemoglobin, having a great affinity for carbon monoxide than oxygen, reacts more readily with carbon monoxide forming carboxyhaemoglobin. The latter can no longer carry oxygen, thus reducing oxygen uptake in the blood. This result in tiredness, headaches, heart damage and quite small amounts can be lethal.
Treatment:
1. Ensure that combustion of fuels is complete. Motorcars can be fit with catalytic converter. The catalytic converter converts harmful gases to less harmful ones.
2. The filters and precipitators must be used in the chimneys of factories.
3. The automobiles must be pollution free by making the fuel alcohol based and using the battery power.
4. Using other energy sources like wind, waves hydroelectric power to produce electricity.
5. Ride less. Use public transport, walk, or ride bicycle for short distances. Car-pooling can be way to reduce carbon emission.
6. Make use of air-friendly products. These products reduce the amount of toxic, ozone-forming chemicals released by traditional cleaning products and are available in most stores, and are typically labeled by the manufacturer as “green” or “eco-friendly”.
7. Plant more trees.
8. Enforce the law. Amendments are to be made to those who do not respect the law.
Water pollution
Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds. Water pollution affects plants and organisms living in these bodies of water and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.
Sources of water pollution and effect:
1. Farming. Farms often use large amounts of herbicides and pesticides, both of which are toxic pollutants. These substances are particularly dangerous to life in rivers, streams and lakes, where toxic substances can build up over a period of time. Farms also frequently use large amounts of chemical fertilizers that are washed into the waterways and damage the water supply and the life within it. Fertilizers can increase the amounts of nitrates and phosphates in the water. This encourages the growth of algae. When the algae dies and decays, it uses up the oxygen in the water. Deprived of oxygen the animal life dies. The water is polluted with dead fish and rotting vegetation and cannot be used. This process is called eutrophication.
2. Factories throw their chemical wastes into the bodies of water. These harmful chemicals such as lead, mercury, and arsenic acids pollute the water of the rivers. Fish, mussels , and other aquatic animals growing in it could eat these chemicals. The people who eat these aquatic animals could get poisoned.
3. The crude oil that spills from boats and ships pollutes the seas and oceans, too. When they cover the surface of water, the oxygen from the air cannot dissolve in it. Aquatic animals that rely on oxygen to live will not be able to breathe. They will soon die. An example is The Gulf of Mexico oil spill which has caused problems to birds among the other marine creatures whose wings had gotten covered by the slick, causing them to die a slow and painful death.
4. Washing clothes and dishes in the rivers and lakes. The detergents used by the people for washing could poison the fish and the other aquatic animals and plants living in them.
5. No proper disposal of sewage. Pathogens present in sewage water spread many different diseases. Stagnant water increases the growth of mosquitoes, which in turn causes malaria.
6. Marine dumping. Dumping of litter in the sea can cause huge problems. Different items take different lengths of time to degrade in water. Materials such as plastics are non-biodegradable. When marine animals or birds consume plastic considering it as food, they die. Thus, causing a decrease in their population.

Treatment:
1. Sewage must be treated in a water treatment plant first before it is discharged into the environment.
2. Strict law to prevent people and industries from dumping and washing clothes or dishes in rivers.
3. Polluted water can be treated with the plant water hyacinth which removes heavy metals from water. For example in China they introduce this plant to reduce water pollution.
4. Water must be purified before distributing to houses.
5. Sensibilising and awareness campaign should be done to make people realize the consequences of polluting the environment.