Pollution is the disposal of pollutants or contaminants which could alter and destroy the natural environment or even an ecosystem. Pollutants have many forms such as solid, liquid, noise and radiation. There are also many types of environment or natural resources that could be subjected to pollution. Pollution could also be naturally occurring although the main type of pollution which could result to major change is manmade (Helmer, 1997). There are many kinds of pollution, but there are three major kinds due to their size and effect which are water, air and soil pollution.
Water is one of the largest amounts of natural resources which could be polluted by contaminants. It is also an essential resource to all kinds of organism so polluting it could cause a major change in the ecosystem or the environment. Polluting water resources could also have a direct impact to man. The major causes of water pollution are the agricultural activities, industrial and process wastewater, oil spills, wastewater sewage, and water runoffs. Agricultural crops usually are induced by pesticides and fertilizers. When it rains, the water runoff washed away these pesticides and fertilizers that could contaminate water bodies. The pesticide could kill the organisms. The fertilizers on the other hand could increase the growth of algae which will reduce the amount of oxygen in the water and kill the organisms (Helmer, 1997).
Industrial processes use water for reaction or cooling their equipment. This water is often disposed to any bodies of water which could cause major changes. Some of these wastewaters contain substances and chemicals that are toxic and could contaminate the water bodies. The wastewater is one of the major point source pollutants which mean the origin of the contaminant could be recognized. Water runoffs especially the urban runoff are also a source of water pollution which is believed to cause large amount of contaminants to any water bodies. When there is rain, chemicals, substances and other toxic materials that come from urban areas could be delivered to the water bodies and result to pollution. Water runoffs are example of non-point source pollutants which refers to contaminants that could not be easily identify its origin (Helmer, 1997).
The common definition of air pollution is the release or disposal of gaseous chemicals and particulates in the air which alters the atmosphere and endangers the lives of many organisms. The most common source of air pollution is also manmade although major effect of it could be caused by volcanic eruptions or meteor collisions. The contaminants of air pollution are often called the greenhouse gases which destroy the atmosphere by altering the heat flow and trapping many light radiations in the earth. The most common greenhouse gases emitted are carbon dioxide, carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), nitrogen oxides, and water vapor. These gases are usually emitted by industrial plants, motor vehicles and residential combustions (Daly & Zannetti, 2007).
One type of air contaminant or pollutant is the photochemical smog which refers to the combination of smoke and fog during the early hours of the day. It is a serious problem to many large urban places such as London and Los Angeles where industrial plants and motor vehicles are abundant which emits large amounts of smoke. The chemical reaction of light and air pollutants could result to airborne particles and even produce ozone which is toxic in a very low altitude. Ozone depletion is also one of the major causes of air pollution. Ozone depletion is the result of the reaction of ozone to major air pollutants such as nitrogen and sulfur compounds. Air pollution could also lead to global warming or climate change. Air pollutants are often regulated around the world to reduce the effect of air pollution (Daly & Zannetti, 2007).
Soil or land pollution is a major problem to humanity since it could affect the ways of life and also affect the ecosystem. Almost all organisms rely on plants as food while the plants rely on the nutrients in the soil. If the soil is contaminated, plants could have difficulties in growing which lead to scarcity of food for humans and animals. Soil or land also provides habitat to most of the organisms. If the soil or land is contaminated with toxic substances or chemicals, then it could not be inhabited which could lead to migration of animals or humans (Heinegg, 2002).
The four main causes of soil pollution are industrial wastes, domestic wastes, agricultural wastes and construction wastes. The most common source of soil pollution is non-biodegradable littering. Plastics, glass and Styrofoam could not be degraded easily which could be the source of pollution if not disposed properly. Solid pollutants should always be segregated to reduce its amounts by recycling. Toxic chemicals and substances that are disposed to land could also destroy the soil property and could not grow any plants. Biological agents such as sludge could also result to soil pollution if not properly disposed or managed (Heinegg, 2002).
Daly, A., & Zannetti, P. (2007). An introduction to air pollution- definitions, classifications and history. The Arab School for Science and Technology. 1-14
Heinegg, A. (2002). Soil contamination and urban agriculture. McGill School of Environment.
Helmer, R. (1997). Water pollution control: A guide to the use to water quality management principles. St. Edmundsbury Press, Great Britain.