All about Smogs

Introduction

Smog is a strange mixture of smoke and fog that is common in cities. The two most well-known smog episodes are the 1952 London smog incident and the photochemical smog closely associated with the 1943 Los Angeles smog incident. Classical smog was caused by excessive SO2 emissions from coal combustion and industrial emissions, whereas photochemical smog is caused by the formation of peroxyacyl nitrate (PAN). Meteorological factors play a significant role in the formation of smog. Smog formation is aided by a stable atmosphere, strong sun rays, and lower temperatures.

Growing urbanisation has resulted in an increase in the number of vehicles, which are sources of smog precursors. It is distinguished by brown hazy fumes that irritate the eyes and lungs, cause breathing problems, and cause rubber cracking and extensive plant productivity damage. Nitrogen oxides, VOCs, ozone, and PAN are the primary constituents of photochemical smog, all of which are harmful pollutants at low altitudes. 

Ozone pollution is affecting the public in Iran as well. The authorities of Tehran province announced in December 2017 that schools would be closed due to smog and high ozone pollution. In general, Tehran experiences high levels of pollution during inversions.

What is Smog?

Smog is derived from the combination of two words: smoke and fog. Smog is also used to describe fog that contains smoke or soot. Smog is a yellowish or blackish fog caused primarily by a combination of pollutants in the atmosphere, primarily fine particles and ground-level ozone. Smog, which is caused primarily by air pollution, can also be defined as a mixture of various gases, dust, and water vapour. Smog is also used to describe hazy air that makes breathing difficult.

Types of Smog

Smog can be sulphurous or photochemical, depending on its origins and characteristics. These are also known as London smog and Los Angeles smog, respectively.

1. Sulfuric smog

Smog in London usually appears during the colder months. As a result, cities near the equator or in the subtropical sphere are unaffected. This type of air pollution is caused by the combustion of coal, the accumulation of particulate matter from industrial activity, and a decrease in temperature. Polluting particles combine with cold air to form a thick fog, significantly reducing overall air quality. Sulfurous smog is distinguished by high levels of sulphur dioxides, nitrogen dioxides, and dust.

2. Photochemical smog (Los Angeles smog)

This type of smog is common in the subtropical region, but there are a few exceptions. Surprisingly, it frequently appears in Polish cities such as Kraków and Warsaw, which are known to suffer from sulphurous smog. It forms primarily during the summer months, when temperatures reach extremes. 

Carbon oxides, nitrogen oxides, and hydrocarbons are the main components of Los Angeles smog. Photochemical smog, as opposed to sulphurous smog, is caused by exhaust fumes and industrial emissions. 

As you can see, the factors that contribute to these two types of air pollution differ. As a result, prevention strategies should be tailored to the specifics of each city. Nonetheless, some measures are universal and benefit both air quality and city dwellers’ comfort. 

Public transportation development, investment in bike paths, the introduction of electric vehicles, and the closure of car-free zones are all decisions that can lead to cleaner air.

Causes of Smog

• Smog-forming pollutants from a variety of sources, such as factories, consumer products, or vehicles, are the most common causes of smog. They are the most urban areas and vehicular emissions contribute to more than half of the smog.
• Smog is mostly caused by the interaction of weather patterns and heavy motor vehicle traffic, as well as industrial and other consumer product emissions. Solvents, paints, plastic packaging, and sprays are examples of consumer products.

Components of Smog

Worldwide, two types of smog pollute the air in industrial areas and large cities. The original smog, a combination of smoke and fog, occurs when emissions from coal-burning factories combine with fog. It’s referred to as industrial smog, and because it was first observed in London, it’s also referred to as London smog.

Since the 1940s, cities near mountains have been plagued by a new type of smog caused primarily by emissions from automobiles and fossil-fuel-burning power plants on sunny, hot days. This is photochemical smog, which was first observed in Los Angeles, and it is unique. In fact, the composition of smog varies greatly from London to Los Angeles. It is unusual to encounter both types of smog at the same time because they occur in different climates and weather patterns.

Conclusion

Smog is a strange mixture of smoke and fog that is common in cities. Introduction Smog is a strange mixture of smoke and fog that is common in cities. The two most well-known smog episodes are the 1952 London smog incident and the photochemical smog closely associated with the 1943 Los Angeles smog incident. Classical smog was caused by excessive SO2 emissions from coal combustion and industrial emissions, whereas photochemical smog is caused by the formation of peroxyacyl nitrate. Growing urbanisation has resulted in an increase in the number of vehicles, which are sources of smog precursors. Smog is a yellowish or blackish fog caused primarily by a combination of pollutants in the atmosphere, primarily fine particles and ground-level ozone.