Air-Pollution

Preliminary Concepts

• Extremely small solid particles and liquid droplets suspended in air.

• Composed of three oxygen atoms joined together.

  • Ozone (O₃): A molecule consisting of three oxygen atoms.

• A highly reactive gas formed by emissions from motor vehicles, industry, unflued gas-heaters, and gas stoves.

  • Nitrogen Dioxide (NO₂): Emitted from various sources, contributing to air pollution.

Air Pollutants Defined

• An odorless, colorless gas which forms when the carbon in fuels doesn't completely burn.

  • Carbon Monoxide (CO): A dangerous gas produced from incomplete combustion of carbon-containing fuels.

• A highly reactive gas with a pungent irritating smell.

  • Sulfur Dioxide (SO₂): Emitted from burning fossil fuels and industrial processes, known for its irritating effects.

Sources of Air Pollution

General Overview

• Air quality in cities is influenced by both natural and anthropogenic (human-made) environmental conditions.

• Air pollution is a serious environmental issue, especially in developing countries.

• The pollutants' emission and transmission forms a path that leads to surrounding polluted air.

• Multiple factors influence each part of the pollution path.

Definition of Air Pollution

• Air Pollution: Introduction of harmful impurities into the atmosphere that affect humans, animals, and plants.

• Air Pollutants: Natural and man-made airborne substances present in concentrations sufficient to affect health and the environment.

Principal Sources of Pollution

• Natural Sources

• Includes materials such as sulfur dioxide, volcanic ash, and steam released during volcanic eruptions, which alter air quality and climatic conditions.

• Man-Made Sources

• Activities such as land clearing for agriculture contribute to air pollution.

• Stationary Industrial or Processing Plants

  • Use machinery that burns fossil fuels like coal, oil, and gas, releasing pollutants during industrial processes.

• Mobile Engine-Driven Vehicles

  • Combustion of gasoline and diesel fuels produces hydrocarbons, carbon oxides, and nitrogen oxides which are emitted into the atmosphere, leading to pollution.

Kinds of Pollutants

• Primary Pollutants: Emitted directly into the environment, such as carbon, sulfur, and nitrogen oxides, plus particulate matter.

• Secondary Pollutants: Formed through chemical reactions in the atmosphere, involving air components and sunlight, such as smog (which includes sulfur dioxide and petrochemical byproducts).

• Note: Both primary and secondary pollutants can be classified as major pollutants.

Major Classes of Air Pollutants

• Carbon Oxides

• Include carbon dioxide (CO₂) and carbon monoxide (CO).

• Sources: Incomplete combustion of fossil fuels in vehicles, industry, and heating.

• Carbon Monoxide Effects: Embeds in hemoglobin in the blood, reducing oxygen transport; particularly harmful to infants, the elderly, and individuals with heart or respiratory diseases, causing confusion and fatigue.

• Sulfur Oxides

• Mainly sulfur dioxide (SO₂), produced during the combustion of coal and oil, particularly in thermal power plants, as well as by paper mills and steel plants.