Pollution - A Rising Environmental Problem

16.1 What is Waste?

Waste is any unwanted or undesired material resulting from industrial, commercial, mining, agricultural operations, and community activities. Waste is classified into two main categories:

• Biodegradable Waste: Substances that can be easily broken down by microorganisms into harmless, non-toxic materials. Examples include animal dung, fallen leaves, and kitchen leftovers.
• Non-biodegradable Waste: Substances that cannot be broken down by microorganisms. Accumulation of these wastes causes pollution. Examples include plastics, styrofoam, glass, metallic cans, and electronic waste (E-waste).

16.2 Pollution

• Pollution: The addition of any constituent to air, water, or land that deteriorates the natural quality of the environment.
• Pollutant: Any constituent or substance that directly causes pollution.
• Types of Pollution: There are five major types: Air pollution, Water pollution, Soil pollution, Radiation pollution, and Noise pollution.

16.3 Air Pollution

Air pollution is the degradation of air quality which harmfully affects living organisms and objects. It is classified into two types:

• Gaseous pollution: Harmful gases released from various sources.
• Particulate pollution: Fine particles like dust, smoke, and debris from wearing tyres or mining.

Sources of Air Pollution:

• Natural sources: Ash from volcanoes, dust storms, and forest fires (beyond human control).
• Man-made sources: Vehicles, industries, burning garbage, and brick kilns.

16.3.1 Vehicular Air Pollution

• Vehicles release gaseous pollutants like Carbon Dioxide (CO2), Sulphur Dioxide (SO2), and Carbon Monoxide (CO).
• They also add particulate pollutants to the air through the wearing of rubber tyres and dust raised by speeding vehicles.

16.3.2 Industrial Air Pollution

• Industries emit massive amounts of CO2, SO2, CO, and oxides of nitrogen.
• Smog: Smoke released from factories mixes with dust and fog drops to create smog. Smog causes asthma, allergies, and harms plants.

16.3.3 Burning Garbage

• Garbage includes fruit peels, dry leaves, and leftovers. Burning this waste instead of composting releases CO2, harmful gases, and adds to particulate air pollution.

16.3.4 Brick Kilns

• Fire-heated enclosures for making bricks. They burn wood, creating large amounts of ash, broken brick bits, heat, and smoke, all acting as pollutants.

16.4 Water Pollution

Water pollution changes water quality, making it unsuitable for living organisms. The five major sources are:

16.4.1 Household Detergents

• Detergents used for washing garments and utensils flow down drains, adding chemicals to the water system.

16.4.2 Sewage

• Liquid waste from domestic activities (kitchen, toilets). Untreated sewage released into rivers spreads disease. Religious practices like immersing dead bodies or ashes into rivers also contribute to this pollution.

16.4.3 Industrial Waste

• Factories produce liquid waste loaded with chemical pollutants, known as effluent, which is discharged into rivers or seas, severely harming aquatic life.

16.4.4 Oil Spills

• Accidental discharge of petroleum into oceans from overturned oil tankers or offshore mining. It coats the water surface, killing marine life and seabirds.

16.4.5 Thermal Pollution

• Power plants and oil refineries release hot wastewater used for machinery cooling. This water, 8-10°C warmer than intake, kills fish and damages aquatic plant life.

16.5 Soil Pollution

Unlike air and water pollution, soil pollution is largely localized. Major sources include:

16.5.1 Industrial Waste

• Industries dump solid wastes like chemical residues, flyash, and metallic ash into the soil.

16.5.2 Urban Commercial and Domestic Wastes

• Solid waste like plastic bags, glass, and kitchen waste are collected by municipalities. Sanitary landfills are ground depressions where this solid waste is dumped and covered with dirt daily.

16.5.3 Chemical Fertilizers

• Excessive use of nitrates and phosphates in farming washes into lakes and ponds. This causes explosive bacterial growth, consuming oxygen in the water and killing aquatic animals.

16.5.4 Biomedical Waste

• Includes discarded needles, syringes, dressings, expired medicines, and biological research material. Careless disposal causes severe harm to soil organisms and human health.

16.5.5 Pesticides

• Pesticides like DDT persist in the environment, altering soil structure, killing nutrient-recycling microorganisms, and entering human food chains.

16.6 Radiation

• Radiation is energy consisting of high-energy particles. Major sources are medical X-rays and nuclear power plants.
• X-rays: Damaging to body cells if exposure is frequent, leading to genetic variations, damaged chromosomes, and bone cancer.
• Nuclear Power Plants: Accidents (like Chernobyl in 1986, Fukushima in 2011) leak dangerous radiation, causing mass casualties, haemorrhaging, and cancers.
• Key radioactive pollutants include Iodine-131 (causes thyroid cancer) and Cobalt-60 (careless disposal caused severe burns/deaths in Mayapuri, Delhi, 2010).

16.7 Noise Pollution

• Definition: Any unpleasant, loud, undesired sound interfering with hearing and concentration.
• Sources: Industrial machines, vehicles, jet aircraft, loud speakers, and firecrackers.
• Harmful Effects: Interferes with communication, interrupts thought/peace, lowers work efficiency, disturbs sleep leading to irritability, sudden loud sounds can damage the eardrum, and it disturbs bird life.
• Measures to minimise: Prohibiting blowing of horns, restricting loud speakers at night, planting roadside trees (which absorb sound), and not burning firecrackers.

16.8 Effects of Various Types of Pollution

A. Effects on Climate and Environment

• Acid Rain: Industrial emissions of SO2 and nitrogen oxides dissolve in rainwater, making it highly acidic. It damages soil vegetation, decays buildings/monuments, and harms aquatic animals by increasing water acidity.
• Greenhouse Effect and Global Warming: Gases like CO2 and methane trap the sun's heat, warming the atmosphere. Increased burning of fuels and deforestation are raising CO2 levels, leading to global warming. This causes melting snow caps, rising sea levels, and reduced food production.
• Ozone Layer Depletion: The ozone layer (O3) high in the atmosphere protects the Earth from harmful UV-B rays. Chemicals like CFCs (chlorofluorocarbons) from refrigerators and aerosols break down ozone. This causes sunburn, genetic disorders, skin cancer, and harms crops. (International Ozone Day: Sept 16).

B. Effects on Human Health

• Air pollution: Causes respiratory problems. Particulate lead causes blood cell shortage, smog leads to asthma/bronchitis, and exhaust gas SO2 damages air passages.
• Water pollution: Leads to diseases like cholera, jaundice, and typhoid.
• Soil pollution: Indirectly causes health issues as pesticides enter food chains.

16.9 Control of Pollution

• Use of unleaded petrol and CNG in automobiles.
• Switching off engines at traffic signal lights.
• Installing tall chimneys in factories fitted with filters and electrostatic precipitators.
• Treating industrial effluents before discharging into water bodies.
• Setting up sewage treatment plants and residential septic tanks.
• Using organic compost over chemical fertilizers, and recycling non-recyclable waste through incineration.
• Planting trees along roadsides to reduce soil erosion and improve air quality.
• Vehicular Standards: Euro Bharat norms (e.g., BS IV, BS VI) control Sulphur and Nitrogen oxides from automobile exhausts. Upgraded norms force vehicle makers and oil refineries to produce cleaner technology to reduce vehicular pollution.

16.10 Swachh Bharat Abhiyan (Clean India Movement)

• Launched on 2nd October 2014, a massive campaign for a clean India.
• Objectives include: Cleaning streets and infrastructure, eliminating open defecation by constructing toilets (ODF India), monitoring latrine use, and achieving solid/liquid waste management.

16.11 Plastic Pollution

• Plastics are highly detrimental because they are non-biodegradable and take hundreds of years to break down.
• Single-use plastics (polythene bags, straws, wrappers) choke landfills, drains, and oceans, harming marine animals and contaminating soil/water.
• Ways to lessen the plastic menace:
  • Observe the three Rs — Reduce, Reuse, Recycle.
  • Carry a refillable water bottle and reusable fabric bags.
  • Avoid disposable plastic cutlery and straws.
  • Give plastic containers to local scrap dealers for recycling.