Major Air Pollutants and their Sources

Major Air Pollutants

Nitrogen and oxygen make up the majority of clean, dry air, accounting for 78% and 21% of the total volume, respectively. The remaining 1% is made up of a combination of various gases, primarily argon (0.9 per cent) and trace amounts of carbon dioxide, methane, hydrogen, helium, and other elements. Water vapour is a standard, though highly variable, component of the atmosphere, ranging in volume from 0.01 to 4%; in highly humid conditions, the moisture content of the air can reach 5%.

The United States Environmental Protection Agency (EPA) has identified six principal air pollutants as “criteria” pollutants, which means that their quantities in the atmosphere can be used as indicators of overall air quality.

1. Oxides of carbon

Carbon dioxide (CO2) and carbon monoxide (COx) are two types of carbon oxides (COx) (CO)

Combustion of coal, oil, and other fuels for energy production, manufacturing, and transportation Biomass combustion

CO affects human health by binding to haemoglobin, resulting in asphyxia; haemoglobin has 250 times more affinity with CO than it does with O2; CO affects human health by binding to haemoglobin, which can result in asphyxia.

2. Oxides of Sulphur

Sulphur oxides (SOx) include sulphur dioxide (SO2), sulphur trioxide (SO3), and sulphate (SO4)

Production Sources:

Sulphur-containing fuel combustion, such as coal; petroleum extraction and refining; paper production; municipal incinerating; ore smelting for metal extraction

Human and Environmental Consequences

SO2 has the most harmful consequences because it damages the lungs of humans and other animals and is a significant precursor to acid rain; other negative impacts include corrosion of paint and metals and injury or death of animals and plants.

1. Hydrocarbons (HCs), commonly known as volatile organic compounds (VOCs)

Types:

Propane (C6H6), Methane (CH4), Butane (C4H10), Ethylene (C2H4), Benzene (C6H6) (C3H8)

Production Sources:

Evaporation from gasoline tanks and carburettors; fuel combustion; biomass; municipal garbage fills; sewage microbiological activity; industrial processes involving solvent changes

Human and Environmental Consequences:

Some are more reactive with sunlight and produce photochemical smog; higher amounts are poisonous to plants and animals; can transform into harmful substances through a complex chemical atmosphere; some are more reactive with sunlight and produce photochemical smog.

2. Nitrogen dioxide

Nitrogen dioxide, a smelly, unpleasant gas, is the most dangerous nitrogen oxide. It is known to produce pulmonary edema, a build-up of fluid in the lungs. Nitrogen dioxide combines with oxygen in the atmosphere to generate nitric acid, which contributes to acid rain. Furthermore, nitrogen dioxide contributes to photochemical smog, a reddish-brown haze caused by sunlight-induced reactions in the lower atmosphere that can be seen in many urban locations.

3. Metals and other inorganic compounds are examples of inorganic compounds.

Lead (Pb), mercury (Hg), hydrogen sulphide (H2S), and hydrogen fluoride (HF) are the most common types (HF)

Production sources include oil wells and refineries, vehicles, municipal landfills, fertiliser, ceramic, paper, chemical, and paint industries, pesticides, fungicides, aluminium production, and coal gasification.

Human and environmental effects include breathing issues, toxicity, death in humans and other animals; crop degradation; and carcinogenicity.

4. Particulate matter suspended in the air (SPM-solid Particles)

Dust, soil, sulphate salts, heavy metal salts, carbon (soot), silica, asbestos, liquid sprays, mist, and other substances

Production Sources:

Building constructions, mining, thermal power plants, stone crushing, industrial activities, forest fires, and garbage incineration are all examples of fuel combustion.

Human and Environmental Consequences:

Have long-term effects on the respiratory system; deposition on the surface of green leaves, obstructing C02 absorption and release; blocking of sunlight; particles with sizes ranging from 0.1 to 10um cause the most lung damage.

Conclusion

Air pollution is defined as the release of pollutants into the atmosphere that is harmful to human health and the environment as a whole. A pollutant is a substance that pollutes an environment, such as water or the atmosphere. It can enter the environment either naturally, as in volcanic eruptions, or by human activity, such as coal and gasoline combustion. The majority of air pollution is caused by energy use and production. When fossil fuels are burned, gases and chemicals are released into the atmosphere. Mould (due to wet conditions produced by extreme weather and increased flooding) and pollen production are both increasing as a result of climate change (due to a more extended pollen season).