- Air pollution can be described as the existence of solid, liquid, or gaseous substances, including noise and radioactive radiation, in the atmosphere at concentrations that may directly and/or indirectly pose harm to humans, other living organisms, property, or disrupt normal environmental processes.
- The escalating use of fossil fuels in various sectors such as power plants, industries, transportation, mining, and construction activities has resulted in air pollution.
- Fossil fuels inherently contain small quantities of nitrogen and sulfur. When fossil fuels like coal (utilized in thermal power plants) and petroleum are burned, they release various oxides of nitrogen and sulfur into the atmosphere.
- These gases undergo reactions with atmospheric water vapor, forming sulfuric acid and nitric acid. These acidic substances descend with rain, causing the phenomenon known as acid rain.
- Acid rain, in turn, leads to the corrosion of structures like the Taj Mahal, a condition referred to as Marble cancer.
- Additionally, pollutants like chlorofluorocarbons (CFCs), commonly found in refrigerators, air conditioners, and aerosol sprays as pressurizing agents, contribute to the deterioration of the ozone layer.
- The combustion of fossil fuels also contributes to an increase in suspended particles in the air, which can consist of unburnt carbon particles or hydrocarbons.
- Elevated levels of these pollutants result in reduced visibility, especially during cold weather when water condenses out of the air. This visible manifestation of air pollution is termed smog.
CAUSE OF AIR POLLUTION
FOSSIL FUELS
- A major contributor to air pollution is sulfur dioxide, emitted during the combustion of fossil fuels like coal and petroleum in power plants and various industrial processes.
- Vehicles, powered by gasoline and diesel engines, burn petroleum, releasing pollutants such as PM, nitric oxide, NO2 (collectively known as NOx), carbon monoxide, organic compounds, and lead.
- Despite being essential for daily transportation needs, the overuse of these vehicles poses a threat to the environment by introducing harmful gases into the atmosphere.
AGRICULTURAL ACTIVITIES
- Agricultural practices contribute to air pollution through the release of ammonia, a hazardous chemical byproduct.
- The use of insecticides, pesticides, and fertilizers in farming introduces harmful chemicals into the air and water.
- Stubble burning, a common agricultural practice to clear fields for new crops, is another source of air pollution, generating hazardous pollutants during the burning process.
Waste on Landfills
- Landfills, where waste is buried or deposited, produce methane—a potent greenhouse gas that is both highly combustible and dangerous.
- Additionally, improper disposal of electronic waste (e-waste) leads to chemical leakage and the burning of wires, further contributing to air pollution.
Industrial Dust and Waste
- Industrial activities release pollutants such as carbon monoxide, hydrocarbons, organic compounds, and various chemicals into the air, adversely affecting air quality.
- Petroleum refineries also emit hydrocarbons and other pollutants, impacting both air and soil quality.
Mining Operations
- The extraction of minerals through mining operations involves the release of dust and chemicals into the air, leading to significant air pollution.
- This not only affects air quality but also contributes to health issues among workers and residents in the vicinity.
Indoor Pollution
- Household cleaning products and painting supplies release hazardous chemicals into the air, contributing to indoor pollution.
- This poses health risks to inhabitants and underscores the importance of proper ventilation.
Natural Factors
- Certain natural phenomena, such as volcanoes, forest fires, and dust storms, can contribute to air pollution.
- While these occurrences are nature-driven, they release pollutants into the air, impacting environmental quality.
CLASSIFICATION OF AIR POLLUTANTS
Based on Persistence:
Primary Pollutants:
- Definition: These pollutants persist in the environment in the same form as when initially introduced.
- Examples: DDT, plastic, carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen and sulphur, etc.
Secondary Pollutants:
- Definition: Formed through interactions among primary pollutants.
- Example: Peroxyacetyl nitrate (PAN) results from the interaction of nitrogen oxides and hydrocarbons.
Based on Existence in Nature:
Quantitative Pollutants:
- Definition: Naturally occurring substances become pollutants when their concentrations exceed a certain threshold.
- Examples: Carbon dioxide, nitrogen oxide.
Qualitative Pollutants:
- Definition: Human-made substances not naturally found in the environment.
- Examples: Fungicides, herbicides, DDT, etc.
FAQs – Air Pollution: Causes and Classification of Air Pollutants
Q1: What is air pollution, and how is it defined?
A1: Air pollution is the presence of solid, liquid, or gaseous substances, along with noise and radioactive radiation, in the atmosphere at concentrations that can directly or indirectly harm humans, other living organisms, property, or disrupt normal environmental processes.
Q2: What are the main contributors to air pollution?
A2: The primary contributors to air pollution include the escalating use of fossil fuels in power plants, industries, transportation, mining, and construction activities. This leads to the release of pollutants such as sulfur dioxide, oxides of nitrogen, and various particulate matter.
Q3: How do fossil fuels contribute to air pollution?
A3: Fossil fuels like coal and petroleum, when burned in power plants and industries, release oxides of nitrogen and sulfur into the atmosphere. These gases undergo reactions with water vapor, resulting in the formation of sulfuric acid and nitric acid, causing acid rain and contributing to air pollution.
Q4: What is the impact of acid rain on structures like the Taj Mahal?
A4: Acid rain, formed by the descent of sulfuric acid and nitric acid with rain, leads to the corrosion of structures like the Taj Mahal. This phenomenon is referred to as Marble cancer.
Q5: How do vehicles contribute to air pollution?
A5: Vehicles powered by gasoline and diesel engines release pollutants such as PM, nitric oxide, NO2 (NOx), carbon monoxide, organic compounds, and lead during the combustion of petroleum. While essential for transportation, overuse of these vehicles introduces harmful gases into the atmosphere.
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