It is a portmanteau of smoke and fog. At the beginning of the 20th century, a heavy haze so often lay over what was then the largest city in the world that the phenomenon was even nicknamed a “London Peculiars”. In December 1952, several thousand people died as a result of respiratory problems and airborne toxins during The Great Smog in London.
Winter smog is caused by a stable inversion, in which the air is stuck and cannot circulate as usual. This allows pollutants accumulate in the air over a longer period of time.
Photochemical smog, also called summer smog, occurs when nitrogen oxides, carbon monoxide, or volatile organic compounds react to form ozone, aldehydes, or nitric acid as a result of UV radiation during periods of fine weather.
The third commonly mentioned form of smog is haze. It is typically made up of dry dust caused by forest fires and predominantly affects countries in southeastern Asia.
Symptoms range from irritation of the mucous membrane and coughing to heart attacks and lung cancer. The sulfur compounds contained in winter smog in particular cause irritation of the respiratory tract and eyes. They are so aggressive that they also cause damage to plants and buildings. Ultra-fine particles contained in smog can also penetrate deep into the lungs and even enter the bloodstream, causing inflammation, blood clotting disorders, and damage to the nervous system. People with chronic lung and cardiovascular diseases are particularly at risk.
Since the emissions associated with smog come from multiple sources, there are also many ways to mitigate it:
Use highly efficient dust removal solutions and switch to clean energy production.
Switch to electric cars or public transport to limit the use of combustion engine vehicles.
Use heat pumps instead of oil heaters, swap petrol-powered lawnmowers, etc. with electric alternatives.