7.1. ENVIRONMENTAL POLLUTION

According to ODUM (1971), Pollution is “an undesirable change in the characteristics of air, water and land that harmfully affect the life and also create health hazards for all living organisms on the globe”. According to SOUTHWICK (1976), Pollution can be defined as “the unfavorable (or) alteration of environment caused by human activities and causing harm to human beings”.

Pollution refers to harmful changes in the environment that adversely affect living organisms. According to scholar ODUM, it is an undesirable alteration that impacts air, water, and land. SOUTHWICK further clarifies that pollution is often caused by human activities and results in harm to humans and possibly other life forms. Understanding this definition sets the foundation for grasping the full impact of pollution on our environment.

Think of pollution like a messy room. Just as a messy room can be uncomfortable and unhealthy for people living in it, pollution creates a harmful environment for all living beings by making air, water, and land unsuitable for life.

Basically the Pollution is of two types viz., (1) Natural Pollution: This type of pollution is limited in its occurrence generally from natural hazards like volcanic eruptions, emissions of natural gas, soil erosion, ultraviolet rays, cosmic rays etc and (2) Manmade Pollution: Most of the pollution is man made only. However, Pollution is usually categorized as Air Pollution; Water Pollution; Thermal Pollution; Noise Pollution; Land & soil Pollution; Radio Active Pollution and Marine Pollution.

Pollution can be classified into two main types: Natural and Manmade. Natural pollution occurs due to natural events such as volcanic eruptions which can release harmful substances into the environment. On the other hand, manmade pollution results from human activities and is most prevalent. This type of pollution can further be categorized into specific areas including air, water, and soil pollution, among others.

Imagine natural pollution like a forest fire caused by lightning—it's harmful but happens without human intervention. Manmade pollution is like littering in a park; it’s a direct result of human behavior and can be prevented through responsible actions.

Air pollution may be described as “the imbalance in quality of air so as to cause adverse effects on the living organisms existing on earth”. Pollution is due to the presence of undesirable substance of sufficient quantity which exists in environment. The substance or energy which causes pollution is called pollutant.

Air pollution occurs when the quality of air is altered in negative ways, which can harm living organisms. Pollutants are the harmful substances found in the air that create this imbalance. Understanding that air pollution is primarily about the presence of unwanted substances helps us identify its cause and potential remedies.

Consider air pollution like the smoke from a barbecue that drifts into your home. Just as that smoke can make it hard to breathe and smell bad, air pollutants create a harmful environment for people and wildlife.

Types of air pollutants: Pollutants may be classified according to origin and state of matter. a) According to Origin: Air pollutants are divided into two categories as primary & secondary. 1) Primary air pollutants are those which are emitted directly into the atmosphere. Eg: C; CO; CO; SOx; N; S; H; NOx; CFC’s etc. 2) Secondary air pollutants are those which are produced in the air by the interaction among the primary air pollutants or by reaction with atmospheric constituents. Eg: Ozone (O3); Smog; Para Acetyl Nitrate (PAN); Acid Rain; Aerosols.

Air pollutants can be categorized based on their origin and physical form. Primary pollutants are directly emitted into the air, such as carbon monoxide or sulfur dioxide. Secondary pollutants, however, are formed in the atmosphere when primary pollutants react with other substances; examples include ozone and smog. This differentiation is crucial for understanding how pollutants interact within our atmosphere.

Think of primary pollutants as ingredients in a recipe you directly add, like flour in a cake. Secondary pollutants are like the cakes that form from those ingredients; they can only exist due to the reactions and combinations of the initial items.

The effects of pollution may be direct and affect certain organisms. The effects of pollution may possess a hazard or nuisance. Long continued pollution even affects the evolution of a species and eliminates organisms that cannot tolerate certain pollutants and favor others who can eat. Air pollution causes deaths, Impair health, reduce visibility and brings vast economic losses.

Air pollution has immediate impacts, harming people and wildlife directly with health issues and deaths. Over time, it can even affect the evolution of species, favoring those that can adapt to pollution while eliminating those that cannot. Additionally, air pollution leads not just to health impacts but economic setbacks due to health care costs and loss of work productivity.

Imagine a city with heavy traffic and smog. Residents might develop asthma and other breathing issues—individuals who cannot adapt may leave the area or become seriously ill, while those who adjust may thrive, just like some animals adapt to pollution better than others.

Prevention and control of Air Pollution: • Inputs that do not contain the pollutants. • Operating process to minimize generation of the pollutants. • Replacing the process with one does not generate the pollutant. • Removing the pollutants from the process. • Substitution of raw materials. Eg: The substitution of high sulphur coal with low sulphur coal in power plants.

Preventing and controlling air pollution involves various strategies. This can include not introducing pollutants at all, improving processes to reduce emissions, or switching to materials that are less harmful. For instance, using low-sulfur coal instead of high-sulfur coal helps cut down on sulfur dioxide emissions and thus reduces air pollution.

Consider a factory that makes cookies. If the factory discovers that the baking ingredients cause a lot of smoke, they could either change the ingredients to a less dusty version or implement a scrubber to clean the smoke before it leaves the factory, similar to how we can improve our air quality by using cleaner technologies.

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