Sources, Types & Impacts of Pollution

Different types of pollution such as air, soil or water makes an effect on the lives of living organisms i.e. humans, plants and animals. It may cause damage to industry, living conditions and our cultural treasure.

Sources, Types & Impacts of PollutionWhen any kind of energy e.g. heat, sound, and radioactivity or different substances in solid, liquid or gas forms are added to our environment at a greater rate and instead of being useful become harmful to the environment.

When any product is added to our natural environment, affects it and nature cannot get rid of it is called pollution.


Pollutants can be defined as anything which is in excessive amount and is severely harmful for our heat, property, environment and comfort.

For example

  • Sewage
  • Wastes
  • Accidental discharges
  • By-products
  • Residues from the production of something useful
  • Compounds used to protect plants and animals

Sources of Pollution

As we know that pollutants come from all types of human activities such as agricultural activities, industrial processes, and countryside land use, all these above activities produce remains and waste material. These materials affect badly three important basics of our life support system i.e. air, water, and soil.

           The main sources of pollution are given below.

  • Industrial discharges from sewage treatment work has nitrogen & phosphorus, non-degradable organic pollutants, pathogens, rubbish, oxygen depleting substances, and suspended solids.
  • Industrial activities release dangerous waste or chemicals to the air, water, and soil.
  • Hydrocarbons, e.g. oil spillage or leakage in seas.
  • Landfill sites release nitrogen, NH3, and oxygen depleting substances, a broad spectrum of chemicals. It is also a source of pathogens.
  • Fish farming releases nitrogen, phosphorus, pathogens and suspended solids.
  • Use of pesticides, insecticides, and herbicides leave chemical waste in the soil.
  • Organic waste recycling and agriculture fertilizer release nitrogen, phosphorus and pathogens.
  • Power generation facilities are the sources of pollution which produce nitrogen, sulphur, mercury and high-temperature pollution.
  • Mining produces heavy metals, acids, suspended & settle-able solids.

Sources of pollution can be further separated into two parts such as.

  • Natural  sources
  • Cultural sources

Sources can be further divided as point and non-point sources of pollution.

Point Source Pollution

The point source pollution is a single distinguishable source of air, water, noise or light pollution.

The point source pollution comes directly from an identifiable source like an industrial pipe or sewage pipe. These sources are attached to industrial production. These sources also contain such discharges that come from water treatment plants. These sources are not limited to any container, pipe, and animal feeding operation, from which pollutants are released or discharged.

Non-Point Source Pollution

Non-Point Sources Pollution is caused by rainfall or the melting of fallen snow. When runoff moves, it carries many pollutants that create from natural and human-made processes. Finally, these pollutants are added into rivers, streams, lakes and groundwater.

Non-Point Source Pollution is defined as pollution that comes from sources rather than from a specific point. Non-Point Source Pollution is also developed from the urban sides such as yards or such areas where crops grow. For example: pesticides, herbicides, fertilizers, wildlife and livestock.

Other important sources of non-point sources pollution include.

  • Litter
  • Hazardous waste
  • Erosion from the construction or home sites
  • Sewer lines leakage
  • Animal feeding operation
  • Oil
  • Pet waste improper use of different chemicals
  • Acid rain and fog contain acid
  • Road salt
  • Sediment
  • Bacteria
  • Sewage and garbage

Rainfall and snowmelt carry these contaminants and deposits them into streams, lakes and rivers as non-point sources of pollution.

Non-Point Sources in Rural Areas

Non-point sources are frequently associated with agricultural practices. These sources of pollutants are released from fertilizer use and also pesticide applications. Non-point sources of pollution in rural areas are produced from animal feed operations and cultivation on sharp slopes. These sources produce the least quantity of pollution in forested and grassland areas.

Non-Point Sources in Urban Areas

Urbanization is a major source of pollution. In urban areas, non-point sources are produced from urban bird and pat population, vehicles, traffic that damage the road surfaces, litter accumulation on street, construction activities. These sources of pollution contain many various hazardous contaminants like zinc, lead, oil, grease and polychlorinated biphenyl’s (PCBs).

Urban land mostly used for three basics such as residential, commercial and industrial activities. Such categorization is associated with pollution initiation.

Types of Pollution

There are various types of pollution but here we’ll discuss three major types of pollution.

  • Air Pollution
  • Water Pollution
  • Land Pollution

Air Pollution

Air pollution, visible and invisible pollution, is visible when dark smoke releases from the factories and truck’s exhaust pipes. Natural disasters cause air pollution. Volcanic ash and harmful gases are ejected into the atmosphere by volcanoes erupt. Volcanic ash discolors the sky. Sulfur dioxide which is volcanic gas make the soil infertile. Air pollution kills birds and other organisms in their habitat and kills cattle and human beings.

Air pollution is mostly due to the burning of fossil fuels, oil and natural gas. Traffic and factories also produce pollutants such as nitrogen oxide and sulphur dioxide, when reacting with moisture, they alter into acids. Then these acids come back on the earth as acid rain. When these acids enter in the lakes, streams then lakes become acidic, fish can’t survive.

Water Pollution

Polluted water is unfit for drinking and other purposes. People who drink polluted water are sick years later due to hazardous chemicals. Polluted water is harmful to people indirectly. Fishes that live in their water are unsafe for eat because pollutants enter their meat. Water pollution occurs due to human activities. Hazardous chemicals are dumped or enter into waterways by seepage. Oil spills, sewage that is not properly treated, fertilizers used in agriculture, garbage are the sources of water pollution.

Soil Pollution

Pollutants that contaminate the water are major sources of soil pollution. Sometimes mining leaves, the dangerous chemicals which contaminate the soil. Pesticides and fertilizers are applied in the agricultural fields. They can be harmful for the plants, animals and human beings. These pesticides are absorbed in the vegetables and fruits when people consume them, they enter into their bodies and cause cancer and diseases. Dichloro diphenyl trichloroethane (DDT) is a chemical used to kill insects. It also causes soil pollution. Now it is banned in all worked, landfills not completely seated off from the land them pollutants leak into the Earth and cause soil pollution.

Impacts of Pollution

Human Health

Pollution is a wide range problem all over the world. Its potential impact is mostly on human beings. All types of  Pollution occurs from various sources, have lethal effects on human growth. Industries produce many chemicals and elements e.g. mercury enters into the water which accumulate in fish. When people consume the fish then this element causes nervous disorders and paralysis. Dichloro diphenyl trichloroethane (DDT) is a chemical pollutant which also affects human health.

Natural Resources

Soil, forested areas, and rivers play an important role in the earth’s environment. All these ecosystems provide natural habitat for animals, plants and other organisms. Pollution has an extraordinary bad effect on these natural resources due to which their performance quality is not better now.

Effects on Soil

Many external inputs such as fertilizers, pesticides and herbicides are used for maximizing productivity and economic returns. But these fertilizers remain in soil when applied in excess amount then they affect the soil ecology. Some pollutants such as Cr & Cd are directly toxic to plants and animals.

Ozone Depletion

Different gases as carbon dioxide, carbon mono-oxide, SOx & NOx released from industries and factories in the atmosphere. These gases have damaged the ozone layer. Due to pollution and gases, ultra-violet rays come to the earth ‘s surface. These rays cause skin cancer and other diseases.


Nutrients are applied to plants such as phosphorus & nitrogen in water bodies causes eutrophication. When these nutrients enter in the water bodies then competition develops between algae and other aquatic organisms. Algae growth is increased due to these nutrients. Then eutrophication occurs. But aquatic life more disturbs due to this.


Pollution is increasing day by day. The level of pollution is mostly enhanced by human activities. Due to human activities, all types of pollution are produced. Different chemicals and elements are released from industries and agricultural practices which are harmful flora, fauna and also aquatic life. But this pollution can be managed and controlled by different methods.

Industrial effluents can be treated with different chemicals. Landfill is the most common and cheapest method for the disposal of solid wastes in the worldwide. Contaminants in the soil and other environment can be detoxified by micro-organisms, plants, and plant enzymes. It is the need of the hour to overcome this problem for the betterment of the environment and the coming human race.

By Hafiza Asma Batool

University of Agriculture Faisalabad, sub-campus Burewala