Definition of Smog

Smog covers industrial areas and large cities all over the world. Smog comes from the words "smoke" and "fog" put together to describe this relatively recent environmental feature, which looks like a foggy cloud but is littered with pollutants and toxic additives. Cities and countries try to reduce smog with legislative measures limiting pollution, but in today's world, it is still a phenomenon brought on by industry.

History

• Smog appeared in human history when industry and coal burning became common, especially in larger cities. London had some of the first documented smog occurrences in the 14th century, caused by its great population density and the amount of coal being burned for personal heat in homes. The Industrial Revolution, which used coal as a main source of power, spread smog throughout the world. Urban populations, especially with a heavy density, suffered with smog until measures like clean-air acts were put into place to reduce the pollution in cities.

Identification

• Thick smog reduces visibility down to about a foot, and coal-induced smog actually leaves particles on clothing, hair and skin. Today, smog occurs when emissions from vehicles and power plants react with sunlight and atmosphere to generate pollutants (mostly ozone) with effects, while not as obvious as smog produced from coal, that create a thick, heavy air in a large or dense city and create a danger to the public.

Health Risks

• Dangerous or unhealthy smog, according to the Environmental Protection Agency (EPA), has 80 or more parts per billion of ozone. Thick smog episodes, intensified during different weather conditions or increases in industrial work or population, cause severe health problems (generally lung related), and can lead to death. London's death rate more than doubled in the winter of 1952 because of an increase of smog from more burning of coal, and other cities like New York and Los Angeles have experienced smog-related deaths related to powerful smog occurrences.

Geography

• Dense populations and heavy industrial zones produce the most smog in an area. Los Angeles has the most smog in the United States, according to the EPA, but increasing smog occurs in New York. Even smaller cities in Michigan do not currently meet guidelines for clean air. Around the world, London, Sao Paulo and Mexico City are considered to have unsafe or unhealthy air.

Prevention/Solution

• Countries realize that smog is a serious issue, with health risks to populations and environmental problems in a global setting. In America, the EPA sets guidelines for cities, and legislation tries to reduce emissions from industry and vehicles to cut smog in unsafe cities. Countries across the world use similar measures, cutting back on factory and vehicle emissions, especially in urban or industrial areas, to reduce smog and prevent global environmental and atmospheric problems.