Causes of Photochemical Smog

Photochemical smog is formed by a confluence of human activity, meteorological circumstances, and geographic elements, underscoring the complicated interactions of air pollution in urban and industrialized areas.

Vehicle Emissions

• Vehicle exhaust is one of the main sources of volatile organic compounds (VOCs) and nitrogen oxides (NOx).
• As fossil fuels like gasoline and diesel are used in combustion engines, NOx and VOCs are released into the air by automobiles, trucks, and other vehicles.
• A large amount of urban air pollution is caused by automobile emissions, particularly in places with high traffic density.

Industrial Processes

• The production of chemicals, electricity, and other industrial processes are the main sources of emissions of NOx and VOCs.
• Industrial facilities release NOx through a variety of chemical reactions and combustion processes. Industrial operations including painting, printing, and solvent use create volatile organic compounds (VOCs).
• These emissions influence the levels of air pollution in cities and regions.

Natural Sources

• Although natural sources also contribute to NOx and VOC emissions, human activity is the main cause.
• For instance, flora releases volatile organic compounds through processes like plant metabolism and breakdown, while lightning strikes can create nitrogen oxides.
• The relative significance of natural sources varies based on variables including kind of plant, soil properties, and weather patterns.

Temperature Inversion

• Temperature inversions are one type of weather that might make smog development worse.
• A temperature inversion stops pollutants from spreading vertically by trapping colder air near the surface in a layer of warm air.
• Smog builds up as a result of the accumulation of contaminants released from many sources due to this stagnant air mass.

Sunlight

• One important component in the creation of photochemical smog is sunlight.
• The energy required to start chemical interactions between NOx and VOCs, which produce ozone and other secondary pollutants, is provided by intense sunshine.
• As a result, areas that receive a lot of sunshine, such bright cities or places with a lot of traffic, are more likely to develop smog.

Geographical Features

The concentration and distribution of pollutants can be influenced by geographical variables, including landscape and proximity to sources of pollution.

• Because there is less air movement in valleys and basins encircled by mountains, smog deposition can be more severe.
• Furthermore, because of localized emissions, metropolitan neighborhoods close to industrial zones or important traffic routes may have greater pollution levels.

Photochemical Smog is related to the pollution of air and emerges when sunlight interacts with contaminants, mostly from industrial and vehicular emissions. Photochemical smog contains pollutants such as nitrogen oxides, volatile organic compounds (VOCs), and sunlight. They can cause respiratory issues and eye discomfort. Its appearance in the atmosphere is hazy and brownish-grey. In this article, we will study the composition, formation, causes and effects of the photochemical Smog in detail.