ESSAY ON ENVIRONMENTAL POLLUTION
INTRODUCTION
Pollution is contamination or undesirable changes in the environment which is harmful for the plants, animals and microorganisms. It spoils physical, chemical and biological characteristics of air, water and soil.
POLLUTANTS– are such substances which causes pollution. These substances affect the usefulness of a resource, may cause long- or short-term damage by changing the growth rate of plant or animal species, or by interfering with human amenities, comfort, health, or property values. There are two basic types of pollutants, defined here.
Non-degradable- such pollutants either don’t degrade or degrade very slowly in the nature and these are not cycled in ecosystem naturally. Examples- mercuric salts, aluminum cans, long chain phenolic, DDTetc.
Biodegradable Pollutants- such pollutants degrade easily in the nature. These are domestic wastes and create problems when accumulated.
TYPES OF ENVIRONMENTAL POLLUTION
There are three main types of pollution viz. Air pollution, Water pollution and land/soil pollution. These are classified on the basis of the type of environment being polluted. However, on the basis of pollutants involved, pollution can also be classified, e.g. noise pollution, lead pollution, fluoride pollution, radioactive pollution etc.
AIR POLLUTION
it refers to contamination in earth’s atmosphere mainly through gaseous emissions from industry, thermal power stations, automobiles, domestic combustion etc. Air pollution is a significant cause for a number of pollution-related diseases like respiratory infections, heart disease, and stroke and lung cancer. A pollutant can be solid particles, liquid droplets or gases and these may be of natural origin or man made.
SOURCES
- Natural origin- The natural origin activities, however affects limited areas where it occurs.
- Volcanic activities emit sulfur, chlorine and ash particles.
- Smoke and carbon monoxide from wildfires
- Decomposition of dead materials, vegetation, animals
- Radon gas from radioactive decay within the Earth’s crust
- Dust from natural sources where large areas of land with little or no vegetation
- Anthropogenic (Manmade) sources- these are mainly related to the burning of fuel.
- Smoke stacks of fossil fuel power stations,manufacturing facilities (factories) and waste incinerators, as well as furnaces and other types of fuel-burning heating devices. Traditional biomass burning (wood, crop waste and dung) is the major source of air pollution, especially in poor and developing countries.
- Petroleum refineries are the chief source of gaseous pollutants like SO2, NO and NO2.
- Mobile sources include motor vehicles, marine vessels, and aircraft. In the major metropolitan cities, automobile exhausts accounts for 70% of all CO, 50% of all hydrocarbon, 30-40% of all oxides and 30% of all suspended particulate matters.
- Burning for forest and farming management and other farming practices. Fertilized farmland may be a major source of nitrogen oxides
- Fumes from paint, hair spray, varnish, aerosol sprays and other solvents
- Waste disposal areas generate methane which is highly inflammable
- Military resources, such as nuclear weapons, toxic gases, rocketry etc.
Health effects of Air pollution–
The health effects caused by air pollution include difficulty in breathing, coughing, asthma and worsening of existing respiratory and cardiac conditions. The human health effects of poor air quality are far reaching, but principally affect the body’s respiratory system and the cardiovascular system
Prevention & control of air pollution
For the prevention, control and eventually reduce the air pollution, here are some steps/ways that must be taken-
- Use of alternative & clean Energy production
- Conservation of energy
- Eco-friendly Automobiles/transportation
- Appropriate act and rules
Water pollution occurs when harmful substances damage the physical, chemical or biological characteristics of water bodies and usually by human activities. Water bodies include lakes, rivers, oceans, aquifers and groundwater. Major sources of water pollution are sewage & other wastes, industrial effluents, agricultural discharge and industrial wastes from chemical industries, fossil fuel plants and nuclear power plants.
- Surface water pollution- it includes pollution of rivers, lakes and oceans. Marine pollution is subset of water pollution.
- Marine pollution- it is defined as the discharge of undesirable and harmful substances in oceans water which contaminate the quality of water, that is harmful to marine ecosystem and use of sea water too. The major sources of marine pollution are sewage, industrial effluents, synthetic detergents, pesticides, fertilizers, heavy metals, plastic, radionuclide wastes, oils and petroleum products.
- Mercury pollution- the main source of Hg-containing effluents is chloral alkali plant. Effluents from batteries, thermometers, fluorescent light tubes, high density street lamps and switch making industries also contain Hg.
- Lead pollution- effluents of lead and lead processing industries are main sources of lead to water
- Sources– Surface water and ground water have often been studied and managed as separate resources even though they are interrelated. Surface water seeps through the soil and becomes groundwater. Conversely, groundwater can also feed surface water sources. Sources of surface water pollution are generally grouped into two categories based on their origin.
Control of water pollution–
- Recycling & Re-utilization of waste
- Removal of pollutants
- Reduction of waste input
- Control of urban runoff
- On-site sanitation and safely managed sanitation
- Control through law & enforcement of standard
Soil is basis of life where we reside and get our food supply. Though soil is not a renewable resource and its degradation can be rather rapid while, it takes thousands of years to form and regenerate. Soil pollution as part of land degradation is caused by the human-made chemicals or other alteration in the natural soil environment. It is mainly caused by industrial activity, agricultural chemicals or improper disposal of waste.
Sources of soil pollution
- Agrochemicals & farming practices
- Disposal of solid wastes on land
- Radioactive pollutants
- Biological agents
- Heavy metal pollutants– from industrial discharge and from sewage sludge.
Natural sources of soil pollution are volcanoes, tsunami waves and storm in desert.
Effect of soil pollution
- Contaminated or polluted soil directly affects human health through direct contact with soil or via inhalation of soil contaminants which have vaporized; potentially greater threats are posed by the infiltration of soil contamination into groundwater aquifers used for human consumption. Such consumption leads to pollution-related diseases.
- Chronic exposure to chromium, lead and other metals, petroleum, solvents, and many pesticide and herbicide formulations can be carcinogenic, can cause congenital disorders, or can cause other chronic health conditions.
- Excessive use of pesticides, herbicides and fertilizers adversely affect the soil quality and their residues remain longer in soil.
- Heavy metals and toxic substances from mining can destroy microorganism of the soil. Infant and children get more effective since rate of retention and absorption of heavy metals is higher in their body.
Control of Soil Pollution
- Recycling and Reuse of wastes
- Proper dumping of urban and industrial wastes
- Adoption of sustainable agriculture, organic farming, use of bio fertilizers, bio integrated pest management.
- Production of natural fertilizers
- Proper sanitation- People should be trained regarding sanitary habits.
- Control of soil erosion.
- Public awareness
- Afforestation, social & agroforestry
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