Environmental pollution refers to the contamination of the natural environment by naturally occurring or man-induced substances that leads to an interruption of the normal environmental processes. Pollution involves the introduction contaminants that are harmful to living organisms and including human beings. Environmental pollution can broadly be classified into three categories namely: soil pollution, air pollution, and water pollution. Pollutants are sometimes naturally occurring substances. These become contaminants when they occur in excess in the environment (Hill, 2010).
Pollutants can be divided into two main categories depending on their decomposition properties. The two include biodegradable and non-biodegradable pollutants. Degradable pollutants are those that can undergo decomposition or be processed by organisms. Examples of these include organic waste products, inorganic salts, and phosphates. Biodegradable pollutants are considered harmless to a certain extent. However, their accumulation in large amounts can pose a serious threat to the environment especially if they exceed the environment’s capacity to assimilate them. Non-biodegradable pollutants are those which are not decomposable by living organisms. They can therefore persist in the environment for longer duration. Examples of these include metal, plastics, radioactive isotopes, glass, and others (Farmer, 2013).
Air pollution occurs when harmful gases are released into the atmosphere. The most common source of air pollution is through burning of fossil fuels which release carbon dioxide into the atmosphere. This may either be from industries, motor vehicle exhaust fumes, or from homes. The large volume of carbon dioxide released into the atmosphere is linked to climate change. Other air pollutants include nitrogen dioxide, sulfur dioxide, airborne particles, volatile organic compounds, and radioactive pollutants. Air pollution may lead to lung infections and other form of diseases in human beings (Farmer, 2013).
Water pollution occurs when effluents or contaminants find their way into water bodies, impacting the marine ecosystem. Discharge of effluents in rivers and other water basins cause water pollution. Groundwater pollution may also occur when chemical contaminants seeps into the ground. This is also a form of water pollution. Industrial waste and raw sewage are the most common sources of water pollution. Heat is another form of water pollution that leads to what is commonly referred to as thermal pollution. Water pollution greatly impacts the marine ecosystem, causing deaths of various species. Water pollution can contribute to water-borne diseases, allergies, skin rashes, and other types of ailments (Hill, 2010).
Soil pollution occurs when contaminants or land use practices alter the natural soil environment. Soil pollution may result from agricultural chemicals, improper waste disposal practices, poor farming practices, destructive land use practices such as mining, and among others. Soil pollution can impact the acidity and alkalinity of soils impacting the diversity of the natural vegetation. Heavily polluted soils have little vegetation cover which consequently impacts the diversity of vegetation and wildlife in a particular area (Hill, 2010).