EVERYDAY SCIENCE

Detailed explanation-1: -Photochemical smog is a brownish-gray haze caused by the action of solar ultraviolet radiation on atmosphere polluted with hydrocarbons and oxides of nitrogen. It contains anthropogenic air pollutants, mainly ozone, nitric acid, and organic compounds, which are trapped near the ground by temperature inversion.

Detailed explanation-2: -An example of a secondary pollutant is ground-level ozone. Ground-level ozone forms when the ultraviolet rays of the sun cause emissions from cars, trucks, and other sources to react with oxygen in the atmosphere.

Detailed explanation-3: -Pollutants released by motorist vehicles include carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxide (NOx) in the form of nitric oxide (NO) and nitrogen dioxide (NO2), hydrocarbons (HC), sulfur oxides (SOX) in forms of sulfur dioxide (SO2) and sulfur trioxide (SO3), and particulate matter (PM10).

Detailed explanation-4: -What is photochemical smog? Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, creating a brown haze above cities. It tends to occur more often in summer, because that is when we have the most sunlight.

Detailed explanation-5: -But at ground level, ozone is an air pollutant that harms people and plants. Ground-level ozone forms when nitrogen oxides and volatile organic compounds react with each other in sunlight and hot temperatures. This pollution comes from vehicles, industry, and other sources and contributes to smog formation.