Air Pollution is a critical environmental issue that has significant implications for human health, ecosystems, and climate change. This detailed guide on causes, major pollutants, and effects of air pollution highlights key facts, global statistics, and natural/human sources relevant for students and exam preparation. Understanding air pollution sources, classification, and health impacts is essential for environmental awareness and academic studies in geography and environmental science.
Air Pollution: Causes, Major Pollutants, and Effects in Environment Geography 2025
-
Overview of Air Pollution and Its Global Significance
Air pollution refers to the physical, chemical, or biological alteration of the atmosphere. It affects both indoor and outdoor environments and poses risks to human health, crops, ecosystems, and urban infrastructure.
- (i) WHO reports air pollution as one of the deadliest threats, especially in Southeast Asia.
- (ii) United Nations states that nine out of ten people globally inhale polluted air.
- (iii) Air pollution leads to skin irritations, respiratory diseases, and long-term health complications.
- (iv) Damages ecosystems, crops, and built environments, impacting environmental sustainability.
-
Pollutants and Their Primary Sources
Air pollutants are substances contaminating the atmosphere, either naturally or through human activity, affecting air quality and public health.
-
Types of Air Pollutants
Common air pollutants include nitrogen oxides, hydrocarbons, sulphur oxides, carbon monoxide, and particulate matter. They can originate from both anthropogenic and natural sources.
- (i) Vehicle emissions contribute significantly to urban air pollution.
- (ii) Forest fires, agricultural burning, and volcanic eruptions release natural pollutants.
- (iii) Combustion-based power plants and industrial fumes are major human-induced sources.
- (iv) Marine vessels, stoves, and paints also add to atmospheric pollutants.
-
Measurement of Air Pollutants
Air pollutants are quantified for environmental monitoring using two main units:
- (i) Parts per million (PPM): Volume of pollutants per one million volumes of air at 25°C and 760 mm pressure.
- (ii) Micrograms per cubic meter (µg/m³): Mass of pollutants per cubic meter of air, where 1 microgram = 10⁻⁶ grams.
-
Major Types of Air Pollutants and Their Impacts
Understanding the chemical composition, sources, and health/environmental impacts of pollutants is crucial.
- Carbon Monoxide (CO): Produced by incomplete combustion of fossil fuels. High concentrations in urban zones from vehicles and power plants.
- Sulphur Dioxide (SO₂): Major cause of acid rain. 90% of emissions from burning coal and industrial smelting.
- Nitrogen Oxides (NOₓ): Formed during petrol/diesel combustion. Contributes to urban haze and acid rain.
- Hydrocarbons: Includes methane, ethane, propane, butane. Derived from organic decomposition and human activities; causes urban smog.
- Chlorofluorocarbons (CFCs): Synthetic compounds linked to ozone depletion and climate change. Used in refrigeration, aerosols, and foam production.
- Particulate Matter: Solid/aerosol pollutants like soot, dust, asbestos fibers. Some are chemical combinations like ammonia + sulphuric/nitric acid.
-
Causes and Effects of Air Pollution
Air pollution arises from multiple sources and results in serious environmental and health consequences.
-
Major Causes of Air Pollution
- (i) Burning of Fossil Fuels: Vehicles (trucks, cars, trains, airplanes) emit CO₂, CO, N₂O, and smoke. Significant contributor to atmospheric pollution.
- (ii) Mining Activity: Extraction of minerals releases dust and chemicals into the air.
- (iii) Indoor Air Pollution: Household chemicals, cleaning agents, and paints emit toxic fumes.
- (iv) Agricultural Activities: Use of pesticides, fertilizers and stubble burning after harvest pollutes the atmosphere.
-
Adverse Effects of Air Pollution
- (i) Responsible for nearly 800 deaths every hour, surpassing malaria, TB, and AIDS combined.
- (ii) Global Warming: Rising temperatures, sea level increase, glacier melting, disrupting ecosystems and displacing populations.
- (iii) Acid Rain: Sulphur/nitrogen oxides combine with moisture to form acid rain, damaging health, crops, and infrastructure.
- (iv) Respiratory & Heart Diseases: Millions affected, especially children, suffering from asthma, pneumonia, and infections.
- (v) Ozone Layer Depletion: CFCs and hydrocarbons weaken ozone; UV radiation increases, causing skin and eye disorders.
-
Summary: Importance of Understanding Air Pollution
Understanding air pollution causes, major pollutants, and their effects is essential for students and exam preparation in environmental geography. Awareness of fossil fuel emissions, CFCs, acid rain, and respiratory health impacts helps in grasping environmental processes and sustainable solutions. Monitoring pollutants and adopting mitigation strategies can preserve ecosystems and human health for future generations.
Environmental Pollution: Causes, Types, and Impact
