Air, water, and soil pollution
Air, water, and soil pollution are major environmental issues linked to industrialisation and urbanisation. They affect human health, ecosystems, and global climate. Understanding their causes, effects, and control measures is crucial for Class 12 and NEET preparation.
Pollution is the addition of undesirable substances that can cause harmful effects in the natural environment. The major kinds of pollution are air pollution, water pollution, and soil pollution. Although environmental pollution can be caused by natural events such as forest fires and active volcanoes, it can also be caused by the contaminants having an anthropogenic source i.e., a source created by human activities. Pollution of all kinds can cause various environmental issues, have negative effects on wildlife and impact human health.
- Air Pollution
- Water Pollution
- Soil Pollution
- Exam Relevance
- Air, Water and Soil Pollution NEET MCQs
- FAQs on Air, Water and Soil Pollution
Air Pollution
Air pollution refers to the contamination of the air due to the presence of compounds in the atmosphere that are dangerous to the health of people and other living organisms or that affect the environment. Gases such as ammonia, carbon monoxide, sulphur dioxide, nitrous oxides, methane, carbon dioxide, and chlorofluorocarbons, particulate matter including organic and inorganic, and biological molecules are just a few examples of the many diverse forms of air pollutants. In addition to harming humans, animals, and food crops, air pollution can also impact climate change and cause ozone depletion or habitat degradation.
Causes of Air Pollution
Industries and Factories: The primary source of carbon monoxide, organic compounds, hydrocarbons, and chemicals is industry. Manufacturing them, degrades the quality of the atmosphere by dispersing into it.
Fossil Fuel Exploitation: The combustion of fossil fuels emits a large amount of sulphur dioxide into the atmosphere. Carbon monoxide, produced when fossil fuels are burned inefficiently, also contributes to air pollution.
Automobiles: Vehicle emissions, including those from trucks, cars, buses, and jeeps, harm the environment. These are the primary sources of greenhouse gases, and they also have negative health effects.
Paints and Cleaning Products: They release hazardous chemicals into the air. The fresh paint on the walls gives off the scent of the chemicals used to make the paint. Additionally, air pollution has an impact on respiration.
Activities in Agriculture: One of the most dangerous chemicals released during agricultural operations is ammonia. Pesticides, fertilisers, and insecticides all harm the environment by releasing harmful gases.
Mining Operations: Large pieces of machinery are used in the mining operation to remove the minerals from underneath the earth. In addition to polluting the air, the dust and chemicals emitted throughout the operation also harm the health of the workers and residents.
Effects of Air Pollution
Air pollution has caused a number of respiratory and cardiovascular diseases in humans. Over the last several decades, the incidence of lung cancer has increased. Children with asthma and pneumonia are more likely to reside close to polluted areas. Many people lose their lives as a direct or indirect result of air pollution each year.
Because of greenhouse gas emissions, the atmosphere's gaseous composition is out of balance. As a result, the earth's temperature has increased. This increase in the earth's temperature is referred to as global warming. As a result, the sea level is rising and glaciers are melting, which might cause many cities to become submerged.
The major cause of the ozone layer's depletion is the atmospheric release of hydrochlorofluorocarbons, halons, and chlorofluorocarbons. The ozone layer's depletion does not shield people from the sun's dangerous ultraviolet rays, which can lead to eye and skin disorders.
Dangerous compounds like sulphur oxides and nitrogen oxides are emitted into the atmosphere when fossil fuels are burned. These contaminants react with the water droplets, making them acidic and causing acid rain, which harms both plant and animal life as well as people.
The air pollutants that are suspended in water bodies have an effect on aquatic life. Animals are often forced to leave their native habitats due to pollution. They become rare as a result, and numerous animal species have gone extinct as a result.
Prevention of Air Pollution
Using public transportation for commuting
Reuse and recycling of products
Avoid burning trash and smoking.
Use clean sources of energy like solar, wind, etc.
When not in use, turn off electric appliances.
Avoid using fireworks.
Water Pollution
Water pollution is the discharge of pollutants into underground water or into lakes, streams, rivers, estuaries, and seas to the extent that the chemicals interfere with the beneficial use of the water or with the normal functioning of the ecosystems. Water pollution can also involve the discharge of energy into bodies of water in the form of radioactivity or heat, in addition to the release of substances like chemicals, debris, or microorganisms. The four primary causes of water pollution are sewage discharges, industrial activity, agricultural activity, and urban runoff, including stormwater. Surface water pollution (either freshwater pollution or marine contamination) and groundwater pollution are two categories that fall under "water pollution."
Sources of Water Pollution
There are two types of sources of water pollution: point sources and nonpoint sources:
Point Sources: Individual, definite sources or sources from which a definite path of travel into the watershed may be identified, including storm drains, sewage plants, oil spills, etc.
Non-Point Sources: Diffuse sources of pollution originating from an identifiable, diffuse source. Examples include agricultural runoff.
Effects of Water Pollution
The impact of water pollution is determined by the kind of pollutants present and their concentration. The location of water bodies is also essential in estimating pollution levels.
Extreme pollution exists in the water bodies close to metropolitan cities. This is the outcome of industrial and commercial facilities discharging trash and hazardous chemicals into the water bodies.
Aquatic life is significantly impacted by water pollution. Their behaviour and metabolism are altered, which leads to illness and eventual death. Dioxin is a toxin that affects many processes, including reproduction and cancer.
This substance bioaccumulates in fish, fowl, and meat. Toxic substances go up the food chain before they enter the human body.
Pollution affects people, and when faeces are present in water sources, people are more likely to contract illnesses. Infectious illness outbreaks like cholera and others are always a possibility when drinking water quality is poor or inadequate.
The food chain may be significantly impacted by water contamination. Some hazardous compounds, such as cadmium and lead, can cause further disruption at higher levels after entering the food chain via animals (fish eaten by both animals and humans).
Prevention of Water Pollution
Greater degrees of water pollution can be reduced using a variety of methods. Treatment of sewage waste prior to discharging it into aquatic bodies is preferable.
The original toxicity can be reduced, and the body of water itself can break down and render harmless any compounds that are still there. If it has undergone secondary treatment, water can be reused in sanitary systems and agricultural sectors.
The water hyacinth is a particularly special plant with the capacity to take in toxic elements in solution, including cadmium and other comparable substances. Establishing these in areas vulnerable to these types of pollution will significantly lessen the negative consequences.
Soil Pollution
When harmful chemicals are present in the soil at high levels, enough to endanger both human health and the ecosystem, this is referred to as "soil pollution." Industrial activities, agricultural chemicals, or inappropriate waste disposal methods are the main causes of soil pollution. Petroleum hydrocarbons, polynuclear aromatic hydrocarbons (including naphthalene and benzo(a)pyrene), solvents, insecticides, lead, and other heavy metals are the most frequent compounds involved in soil pollution. The level of industrialization and the number of chemical substances are associated with contamination. The main effects of soil pollution are health risks due to direct contact with contaminated soil, inhalation of contaminant vapour, or secondary contamination of water supplies contained within and beneath the soil.
Causes of Soil Pollution
Dumping of industrial waste, plastics, domestic waste, and electronic waste leads to soil contamination.
Mining and manufacturing activities lead to a vast amount of soil degradation.
Excessive usage of pesticides, herbicides, etc. in agricultural practices
Heavy metals (like lead and mercury) can become extremely dangerous for humans when they are present in soils at very high concentrations.
Batteries contain hazardous chemicals, disposing of electrical products like batteries has a negative impact on the soil in the same way that disposing of plastics and other solid garbage does.
Acid rain can cause soil contamination.
Dumping radioactive waste leads to soil pollution.
Effects of Soil Pollution
Human health is significantly impacted by soil contamination. Most of the pollutants are absorbed by crops and plants growing in contaminated soil, which subsequently transfer them to humans. Infections brought on by soil pollution include skin and eye irritation, headaches, motion sickness, coughing, chest pain, and wheezing.
The fertility of the soil will be reduced and the soil's structure will be altered by the regular use of chemical fertilisers, inorganic fertilisers, and pesticides. This will result in a decline in soil quality and subpar crops. The land is no longer suitable for cultivation or for the survival of any native plants due to slowly deteriorating soil fertility.
Different kinds of microbes, birds, and insects depend on the soil as a vital habitat. Thus, altering the chemistry of the soil has the potential to have a detrimental effect on living things and even cause the progressive death of a large number of organisms.
Prevention of Soil Pollution
Reduce the use of chemical fertilisers, inorganic fertilisers, pesticides, and herbicides. Use eco-friendly fertilisers to improve soil fertility.
Afforestation and reforestation should be encouraged.
Reduce, reuse, and recycle the products so that the dumping of huge amounts of waste can be prevented.
One of the finest sources of nutrients for the soil is natural manure. It's fully safe and natural. It promotes the general health of the soil and replenishes vital nutrients. It doesn't generate any hazardous byproducts that could endanger the ecosystem or the land.
Exam Relevance
Given below is the weightage of questions asked from pollution topics in different exams:
Exam Type | Weightage of Pollution Topics |
CBSE Board Exams | 5-7% |
NEET | 3-5% |
Nursing Entrance Exams | 2-3% |
Paramedical Exams | 1-4% |
Air, Water and Soil Pollution NEET MCQs
Q1. Among the following, which one causes maximum indoor chemical pollution?
burning coal
burning cooking gas
burning mosquito coil
room spray
Correct answer: 1) burning coal
Explanation:
Burning Coal: As coal is a solid fuel, it does not burn completely and releases a lot of pollutants with toxic gasses like carbon dioxide (CO₂). As a result, it contributes particularly to indoor pollution.
Burning Cooking Gas: Compared to coal, cooking gas burns cleaner, much like LPG. Because it burns more effectively, it still emits some carbon dioxide, but considerably less.
Burning Mosquito Coil: To keep insects away, mosquito coils emit smoke that contains chemicals. They do not emit as much carbon dioxide as coal, but they do release certain dangerous chemicals and tiny particles.
Room Spray: Because room sprays do not burn fuel, they do not emit a lot of carbon dioxide, but they can produce chemicals known as volatile organic compounds (VOCs), which can pollute the air.
The worst is burning coal since it emits the most carbon dioxide and other pollutants.
Hence, the correct answer is option 1) burning coal.
Q2. Pollution refers to:
Any undesirable change in physical, chemical, or biological characteristics of air, water, or soil.
Any desirable change in forests and rivers
Agents that bring about such an undesirable change are called pollutants
More than one correct answer
Correct answer: 4) More than one correct answer
Explanation:
Any harmful alteration that affects the air, water, or soil unhealthy is referred to as pollution. It may have an impact on the environment's biological, chemical, or physical characteristics. Pollutants are the substances responsible for these detrimental alterations. These could be garbage, chemicals, or other dangerous substances that threaten living beings and the environment. The environment is adversely affected by pollution, which reduces its health for people, animals, and plants.
Hence, the correct answer is option 4) More than one correct answer.
Q3. Non-biodegradable pollutants are created by:
Nature
Excessive use of resources.
Humans
Natural Disasters
Correct answer: 3) Humans
Explanation:
Non-biodegradable pollutants stem from human actions that introduce substances into the environment that resist natural degradation. These substances remain intact for extended periods, often leading to ecological damage. Major contributors include:
1. Plastics: These are artificial polymers that resist breaking down easily, leading to persistent pollution, particularly in marine ecosystems and landfills.
2. Heavy Metals: Elements such as lead, mercury, and cadmium are emitted from industrial activities and mining, and once released, they accumulate in the environment and may cause toxicity in living organisms.
3. Pesticides and Herbicides: Some chemical agents used in agriculture persist and can have detrimental effects on wildlife and environmental components like soil and water.
4. Synthetic Chemicals: Certain industrial compounds, like PCBs, do not degrade readily and can amass in ecological systems, entering food chains.
Hence, the correct answer is option 3) humans.
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FAQs on Air, Water and Soil Pollution
What is the definition of air, water, and soil pollution?
Air pollution refers to the presence of harmful substances such as smoke, dust, and toxic gases in the atmosphere, making it unfit for breathing. Water pollution occurs when industrial waste, sewage, and chemicals contaminate rivers, lakes, and oceans, affecting aquatic ecosystems. Soil pollution is caused by the disposal of plastics, pesticides, heavy metals, and other hazardous materials into the soil, reducing its fertility. All three types of pollution directly affect human health, environment, and biodiversity.
What are the main causes of soil pollution?
Soil pollution mainly occurs due to overuse of fertilizers and pesticides, which accumulate toxic chemicals in soil. Industrial waste and effluents containing heavy metals degrade soil quality. Improper disposal of plastics, biomedical waste, and electronic waste also contribute. Oil spills, acid rain, and leakage from landfills add to contamination. Deforestation and mining activities further disturb soil composition and fertility.
How does water pollution affect aquatic life?
Water pollution severely impacts aquatic life by reducing dissolved oxygen (DO) levels, which fish and other organisms require for survival. The presence of chemicals like nitrates and phosphates causes eutrophication, leading to excessive algal growth that blocks sunlight. Toxic metals and pesticides accumulate in organisms, causing biomagnification through the food chain. Polluted water can also destroy breeding grounds and lead to extinction of sensitive species.
What are the prevention methods for air pollution?
Air pollution can be prevented by reducing fossil fuel combustion and shifting to renewable energy sources like solar and wind. Use of public transport, carpooling, and electric vehicles reduces vehicular emissions. Industries must adopt filters, scrubbers, and catalytic converters to minimize harmful gases. Afforestation and plantation help absorb carbon dioxide. Strict enforcement of pollution control laws and awareness campaigns also play a vital role in reducing air pollution.
Frequently Asked Questions (FAQs)
Sewage treatment, also known as domestic wastewater treatment or municipal wastewater treatment, is a type of wastewater treatment that aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the nearby environment, preventing water pollution from raw sewage discharges.
The types of soil pollution are:
Agricultural soil pollution
Industrial chemicals are causing soil pollution.
Soil pollution is caused by solid waste.
soil pollution due to urban activities.
River Ganges is the most polluted river in India and the fifth-most polluted river in the world.
Chlorine, chlorine dioxide, soda ash, sodium bicarbonate, etc. are a few of the chemicals used during water treatment.
Ozone present in the stratosphere of the earth’s atmosphere is one type of ozone that protects the earth from the sun’s harmful radiation, while ground-level ozone or ozone present in the troposphere is the second type, but this ozone is a secondary pollutant and causes respiratory diseases. Tropospheric ozone causes photochemical smog.
There should be both personal and collective efforts to reduce pollution. We can help decrease waste by recycling, using renewable energy sources, conserving water and so much more. The government has the power to enforce strict regulations on industries, adopt environmentally friendly agricultural practices, and invest in renewable energy sources, among others.
The significant sources of pollution include industrial emissions, wastes not disposed of correctly, agricultural runoff, vehicle exhaust, and excessive use of pesticides and fertilizers.
Air pollution refers to the presence of harmful substances in the air we breathe. It differs from water and soil pollution in that it affects the atmosphere, while water pollution impacts bodies of water, and soil pollution affects land. Air pollutants can travel long distances and affect large areas, whereas water and soil pollution tend to be more localized.
The Air Quality Index (AQI) is a standardized indicator of air quality used to communicate how clean or polluted the air is and what associated health effects might be. It typically considers major air pollutants regulated by the Clean Air Act. The AQI scale usually ranges from 0 to 500, with higher values indicating worse air quality. It's used to inform the public about daily air quality and to help individuals make decisions to protect their health.
Air pollution and climate change are closely linked. Many air pollutants, such as carbon dioxide and methane, are also greenhouse gases that contribute to global warming. Conversely, climate change can exacerbate air pollution by increasing the frequency of wildfires and dust storms, and by altering atmospheric chemistry. Addressing air pollution often has co-benefits for mitigating climate change, and vice versa.
Thermal inversions occur when a layer of warm air settles over a layer of cooler air near the ground, trapping pollutants. This phenomenon prevents the normal vertical mixing of air, causing pollutants to accumulate near the surface. Inversions are common in valleys or during winter months and can lead to severe air pollution episodes, especially in urban areas with high emissions.
Primary air pollutants are emitted directly from a source, such as carbon monoxide from vehicle exhaust or sulfur dioxide from industrial processes. Secondary air pollutants, like ozone and some particulate matter, form in the atmosphere through chemical reactions between primary pollutants and other atmospheric components. Secondary pollutants can be more challenging to control as they don't have a direct emission source.
Smog is a type of air pollution that appears as a hazy, often yellowish or brownish fog. It forms when sunlight reacts with nitrogen oxides and volatile organic compounds (VOCs) in the atmosphere. This photochemical reaction produces ground-level ozone and other secondary pollutants. Smog is common in urban areas with high traffic and industrial activity, especially during warm, sunny weather.
Acid rain is precipitation with high levels of acidic components, primarily sulfuric and nitric acids. It forms when sulfur dioxide and nitrogen oxides, released from industrial processes and vehicle emissions, react with water, oxygen, and other chemicals in the atmosphere. These reactions create acidic compounds that fall as rain, snow, or fog.
Indoor air pollution refers to contamination within buildings, while outdoor air pollution occurs in the open environment. Indoor pollutants often come from sources like cleaning products, building materials, and cooking, while outdoor pollutants are typically from industrial emissions and vehicles. Indoor air can sometimes be more polluted than outdoor air due to poor ventilation and the concentration of pollutants in enclosed spaces.
The greenhouse effect is a natural process where certain gases in the atmosphere trap heat, keeping Earth warm. However, human activities have increased the concentration of these gases, especially carbon dioxide, leading to enhanced heat trapping. This results in a gradual increase in global temperatures, known as global warming.
Particulate matter (PM) refers to tiny solid or liquid particles suspended in the air. It's a major concern because these particles can be inhaled deep into the lungs, causing respiratory and cardiovascular problems. PM2.5 (particles smaller than 2.5 micrometers) is especially dangerous as it can enter the bloodstream. Sources include vehicle emissions, industrial processes, and natural events like dust storms.
The ozone layer in the stratosphere protects Earth by absorbing harmful ultraviolet (UV) radiation from the sun. Ozone depletion is primarily caused by human-made chemicals called chlorofluorocarbons (CFCs) and other ozone-depleting substances. When these chemicals reach the stratosphere, they break down ozone molecules, thinning the protective layer and allowing more UV radiation to reach Earth's surface.
Environmental justice refers to the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to environmental regulations and policies. In the context of air pollution, it addresses the disproportionate impact of pollution on certain communities, often low-income or minority populations. This concept emphasizes that everyone should have equal protection from environmental and health hazards.
Point source pollution comes from a single, identifiable source, such as a factory smokestack or a specific pipe discharging into a water body. Non-point source pollution comes from many diffuse sources, like runoff from agricultural lands or urban areas. Air pollution can have both point sources (e.g., industrial chimneys) and non-point sources (e.g., vehicle emissions across a city). Non-point sources are often more challenging to regulate and control.
Air pollution affects visibility by scattering and absorbing light. Particles and gases in the air can reduce the clarity and color of what we see, especially over long distances. Visual range is the greatest distance at which an observer can see a black object viewed against the horizon sky. Reduced visual range due to air pollution is common in urban areas and can impact transportation safety and aesthetic quality of landscapes.
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