Air pollution can be categorized into several types based on the sources of pollutants, the nature of the pollutants, and their effects on the environment and human health. The main types of air pollution include: Particulate Matter (PM): Particulate matter consists of tiny solid or liquid particles suspended in the air. It includes dust, soot, smoke, pollen, and fine particles generated from combustion processes, industrial activities, and natural sources. PM is categorized into different sizes, such as PM10 (particles with a diameter of 10 micrometers or smaller) and PM2.5 (particles with a diameter of 2.5 micrometers or smaller). These fine particles can penetrate deep into the respiratory system and have adverse health effects. Ground-Level Ozone (Tropospheric Ozone): Ground-level ozone is a secondary pollutant formed when pollutants from vehicles, industrial emissions, and other sources react in the presence of sunlight. It can cause respiratory problems and is a key component of smog. Nitrogen Oxides (NOx): Nitrogen oxides, primarily nitric oxide (NO) and nitrogen dioxide (NO2), are produced by combustion processes, such as those in vehicles and power plants. NOx can contribute to the formation of ground-level ozone, acid rain, and particulate matter. It can also impair lung function and lead to respiratory issues. Sulfur Dioxide (SO2): Sulfur dioxide is released into the air when fossil fuels containing sulfur are burned, such as coal and oil. It can lead to acid rain, irritate the respiratory system, and harm the environment. Carbon Monoxide (CO): Carbon monoxide is a colorless, odorless gas produced by incomplete combustion of fossil fuels. It can interfere with the body’s ability to transport oxygen in the blood and lead to health problems, particularly in enclosed spaces. Volatile Organic Compounds (VOCs): VOCs are organic chemicals that can easily vaporize into the air. They are emitted from various sources, including vehicle exhaust, industrial processes, and certain products (e.g., paints, solvents). VOCs contribute to the formation of ground-level ozone and can have adverse health effects. Heavy Metals: Heavy metals, such as lead, mercury, and cadmium, are toxic pollutants released from industrial activities, mining, and combustion processes. They can contaminate the air, soil, and water, posing serious health risks. Radon: Radon is a naturally occurring radioactive gas that can seep into buildings from the ground. Prolonged exposure to high levels of radon is a significant health concern as it is a leading cause of lung cancer among non-smokers. Hazardous Air Pollutants (HAPs): Also known as air toxics, these are a group of pollutants that include chemicals, metals, and organic compounds known to be harmful to human health. HAPs are emitted from industrial facilities and can cause various health problems. Ammonia (NH3): Ammonia is released from agricultural activities, vehicle emissions, and industrial sources. It can contribute to the formation of fine particulate matter and has environmental and health implications. These various types of air pollution can have a range of adverse effects on human health, ecosystems, and the environment. Efforts to reduce and control air pollution are critical for protecting public health and the planet.