Environmental Pollution means the presence of undesirable substances in any segment of environment, primarily due to human activity- discharging byproducts, waste products, or harmful secondary products, which are detrimental to man and other life forms. Environmental pollution is now considered as a global phenomenon, which is increasingly attracting the attention of human beings or its severe long-term consequences. Over the past couple of decades, various sources of pollution have been identified that affect the composition of water, air and soil of the earth.
Therefore, environmental pollution can be understood as:
- Pollution as local concentration in matter cycling - All ecosystems consist of biogeochemical cycling of matter. Pollution represents an accumulation of matter in harmful concentrations at some stage of matter cycling. For example, soil contamination by nutrients due to the over-application of chemical fertilizers in agriculture.
- Pollution as an accelerated natural process - Human activities accelerate the pace of matter cycling and this causes the generation of matter at toxic concentrations. For example, the burning of fossil fuels releases tonnes of carbon into the atmosphere that is stored as coal or petroleum underground. Had it not been for human consumption of fossil fuels, these would have taken millions of years to recycle.
Types of Environmental Pollution:-
Pollution has become a widespread problem affecting all the natural reservoirs of the planet. Based upon the occurrence of reservoirs, major types of environmental pollution are Air pollution, Water pollution, Soil pollution, Noise pollution, Plastic pollution, Marine pollution,
Air Pollution:-
Air pollution is said to exist if the levels of gases, solids, or liquids present in the atmosphere are high enough to harm humans, other organisms, or materials.
Over the years, air pollution has become the greatest environmental challenge faced by people, especially in urban areas. Most often, it is caused by human activities like the burning of fossil fuels in thermal power plants, and other industrial processes like petroleum refining, smelting, mining, transportation, agriculture etc. In addition to human sources of air pollution, it can also be caused by natural processes. For example, volcanic eruption releases Sulphur dioxide and other pollutants, which react in the atmosphere to produce volcanic smog.
Water Pollution:-
Water Pollution is the contamination of water sources including ponds, lakes, rivers, groundwater, and the ocean. Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without removing harmful compounds.
Water pollution affects plants and organisms living in these bodies of water as well as human communities that use the polluted water.
Mankind has long dumped its waste into natural waters because the waste can be quickly diluted and dispersed. As the human population grew, the waste disposed into rivers far outpaced the ability of natural streams to cleanse themselves. This has made water pollution one of the greatest problems in the world today.
Here are some UN statistics and facts on Water Pollution:
- Every day, 2 million tonnes of human waste are disposed of in water bodies.
- At least 1.8 billion people worldwide are estimated to drink water that is fecally contaminated.
- In developed countries, 70% of industrial wastes are dumped untreated into waters where they pollute the usable water supply.
Soil Pollution:-
The population of the whole world is increasing at a very fast rate. Therefore, the demand for food is also increasing. More agriculture is needed to produce more crops. Farmland is used more or more to increase crop productivity. If soil is more used for farming, then it increases soil erosion. If more irrigation is used, then it causes waterlogging and the salinity of the soil. Then, it decreases the fertility of the soil and hence decreases crop production. Chemical fertilizers make the soil poisonous and the land becomes degraded.
When the structure and composition of the soil are destroyed due to any reason, then it causes a gradual loss of soil fertility. This harms crop production. Different plant species cannot grow on such soil. This is called desertification of soil.
Soil gets polluted mainly due to some causes like Soil erosion, Salinization (Excess salts and water), and excessive use of fertilizers and solid waste which adds harmful chemicals and other materials to the soil.
Noise Pollution:-
Noise is defined as unwanted sound and it is an irritant and a source of stress. Most of the noise one hears originates from human activities. The main sources are:
Transport sector: aircraft, trains, trucks, tractors, cars, and motorcycles contribute the maximum noise.
Industrial and construction machinery: factory equipment, generators, pneumatic drills, road rollers, and similar machinery.
Special Occasion: High-volume sound from loudspeakers during music performances, Different religious festivals, public meetings etc.
Noise pollution is increasing in industrial societies and in cities everywhere.
Plastic Pollution:-
If there is one type of waste problem, that is ubiquitous, it is plastic pollution. The most worrisome feature of plastic pollution is that it remains in the environment for centuries. Most plastics are non-biodegradable. Over time, they slowly break down into smaller fragments known as ‘Microplastics’.
A few important facts about plastic pollution as per United Nations Environment Program (UNEP):
- About 8 million tonnes of plastic end up in the world every year. Rivers carry plastic waste from deep inland to the sea. This contributes to marine pollution.
- Globally about 300 million tonnes of plastic waste is generated every year. Half of all plastic produced worldwide is used only once and then trashed away. most common examples of single-use plastic are cigarette butts, plastic drinking bottles, plastic bottle cups, food wrappers, plastic grocery bags, straws and foam take-away containers.
- Developed countries like the United States, Japan and many European countries produce significant amounts of plastic waste. Per capita annual plastic consumption in the USA is about 100 kg, in Europe, it is around 65 Kg and in China is around 40 kg. This is much higher than the global average of 28 kg of plastic use per person annually.
Marine Pollution:-
Since the ocean forms 71% of the earth’s surface, most of the pollutants in the atmosphere fall on it. In recent decades, however, there is, in addition, a huge amount of direct marine pollution caused by human activities.
Industrial discharges and agricultural run-off containing pesticides, fertilizers, and various toxic chemicals find their way to the ocean. Treated and untreated human and other domestic waste (about 6 million tonnes a year) end up in the ocean with all their contaminants. In fact, sewage remains the largest source of contamination of the coastal and marine environment.
The oil industry contributes to deadly pollution through leaks, spills, and cleaning of tankers. Nitrogen input into the ocean has been rapidly increasing due to agricultural runoff, atmospheric deposition, and loss of natural interceptors like coastal wetlands, coral reefs, and mangroves. The result is greater marine and coastal eutrophication. Another concern is the increasing amounts of non-biodegradable waste like plastic that float in the ocean. A large number of birds, turtles, and mammals are killed by entanglement in or ingestion of such waste.
Sources of Environmental Pollution:-
Major sources of environmental pollutants are:
- Industrial Sources - Major industries contributing to pollution are manufacturing; power generation like coal-based power plants; mining, and construction. Different industries, based on their nature, can cause air, water or soil pollution.
- Agricultural Sources - The cultivation of crops and animals generates agricultural wastes. These are rich in nutrients like nitrogen and phosphorous. They may enter into water streams as agricultural run-off or stay on land causing soil pollution,
- Domestic Sources - These include households that generate sewage rich in nitrogen and phosphorous causing water pollution
- Vehicular Sources - Petrol and diesel-based automobiles like cars, heavy-duty trucks, and passenger vehicles all generate toxic exhaust fumes. These emissions are mainly responsible for air pollution.
Effects of Environmental Pollution:-
Environmental pollution can be hazardous for all living beings.
- Carbon dioxide and carbon monoxide are the two oxides of carbon that are important air pollutants. Carbon monoxide is absorbed in our body through breathing. This decreases the oxygen-carrying capacity of the blood. Symptoms of carbon monoxide poisoning are Chest pain, Difficulty in breathing, Vomiting, Unconsciousness and death at higher levels.
- At low levels, air pollutants irritate the eyes and cause inflammation of the respiratory tract. If the person already suffers from a respiratory illness, air pollution may lead to the condition becoming chronic later. It can also accentuate skin allergies.
- Many pollutants also depress the immune system, making the body more prone to infections. Particulate matter can reduce visibility, soil clothes, corrode metals, and erode buildings. On a larger scale, air pollution leads to acid rain, ozone layer depletion, and global warming.
- Many metals like mercury, lead, cadmium, arsenic, nickel etc. are very toxic in nature. Minamata disease occurred in Japan due to mercury poisoning.
- High level of arsenic in drinking water leads to stomach pain, diarrhoea, impaired nerve function, and serious sensations in hands and feet. It also causes cancers such as skin, lung, kidney and bladder cancer.
- Pesticides are toxic chemicals that are used for agriculture to destroy pests. Pesticides badly affect the nervous system of animals and human beings. Pesticides kill many helpful bacteria, earthworms, snails, and bird species. This disturbs the food chain.
- Acid rain and excessive use of chemical fertilizers result in the soil becoming unable to hold nutrients. Then, it decreases the fertility of the soil and hence decreases crop production. Different plant species cannot grow on such soil. It causes a loss in biodiversity.
- Plastic bags can block waterways and exacerbate natural disasters like flooding.
- By clogging sewers, plastics provide breeding grounds for mosquitoes and pests. This is because plastic bags can increase the transmission of vector-borne diseases like malaria.
- Microplastics are a bigger problem as it is easily ingestible by fish. This way, plastics eventually enter human food chains, Microplastics have been detected in marine organisms from plankton to whales, in commercial seafood and even in drinking water.
- Styrofoam products are generally used for making disposable plastic cutlery like glasses, cups etc. It contains carcinogenic chemicals like styrene and benzene. These can damage the nervous systems, lungs and reproductive organs.
- Plastic bags are often mistaken for food by turtles and dolphins. Marine organisms like dolphins, turtles, whales, and fishes can ingest them and have been found blocking the airways and stomachs of hundreds of species.
- Unwanted sound or noise pollution causes irritation and disturbance to the listener. Loud noise causes a sensation of pain in the ear. Listening to noise for a longer period of time badly affects hearing ability. It may sometimes cause loss of hearing.
Pollution Control Measures:-
Environmental pollution has become a globally pervasive problem. It is clear that the amount the types of waste generated by human activities are beyond the capacity of natural ecosystems to process and detoxify many environmental scientists have offered many scientific and technological solutions for pollution abatement. In modern times, A novel concept is dominant in waste management, known as Integrated Waste Management. It is defined as a set of methods involving 3Rs - Reduce, Reuse, Recycle.
- Reduce- It refers to reducing the generation of waste in the first place. It will involve reducing consumption and major lifestyle changes by all and most importantly by the developed countries. For example, simple changes like saying no to plastic straws and cutlery can make a big difference.
- Reuse- It involves reusing products in the same form or modified form for multiple uses or other uses. For example - washing and re-using plastic containers; and making cloth bags from old clothes. Usually, people in developing and low-income countries are more efficient in reusing things.
- Recycle- It means using waste as a raw material for secondary industrial processes. For example - recovering old aluminium cans, melting them down and using the recovered aluminium to manufacture new products.
However, for this to happen, it requires massive awareness generation amongst all the people, industry and Government. Thanks to many environmental agencies and organisations like the UN, awareness is on the rise. And this has encouraged many people to make positive changes for pollution reduction.
FAQs on Environmental Pollution
Let us look at some of the frequently asked questions about environmental pollution:
Q. What is Environmental Pollution?
Answer.- It refers to excess out/discharge of any material into the environment in amounts harmful enough for humans, other life or valued assets like buildings.
Q. What are the major causes of environmental pollution?
Answer - Anything that includes the addition of unwanted chemicals that cause a change to the environment is environmental pollution. Examples of environmental pollution are Air, Water, Soil, Noise, and Plastic Pollution.
Q. What is Eutrophication?
Answer - It is the process by which a body of water develops a high concentration of nutrients, such as nitrogen and phosphorous resulting in abundant plant and algal growth.
Q. What is the Great Pacific Garbage Patch?
Answer - It is a convergence zone of floating plastic debris in the Pacific Ocean halfway between Hawaii and California.
Q. What is Harmful Algal Bloom?
Answer - These are the large colonies of algae and other photosynthetic organisms that proliferate uncontrollably in the ocean’s brackish water or freshwater bodies.
Q. What is Ocean Acidification?
Answer- The process of formation of carbonic acid in the sea waters due to the absorption of carbon dioxide from the atmosphere system and lowering of ocean pH over an extended period of time.
Q. What are Persistent Organic Pollutants?
Answer - It refers to those pollutants that don’t break down easily and remain in the environment for a long time.
Q. What is Photochemical Smog?
Answer - It refers to smog formed by reactions between Nitrogen Oxides and volatile organic compounds in the presence of sunlight.
Q. What is the Pollution Haven Hypothesis?
Answer - It refers to the hypothesis that globalisation causes polluting activities to concentrate in poor and developing countries of the world.
You may also read - Global Warming | Greenhouse Effect, Causes and Effects of Global Warming.