Smog facts for kids

Claude Monet's painting of London smog in 1904. It was mainly caused by burning coal in homes and trains

Smog is a type of air pollution. The word "smog" is a mix of "smoke" and "fog." It happens when smoke and other harmful gases get trapped in the air, often making it hard to see.

What is Smog?

There are two main types of smog:

Classic Smog

Classic smog happens when lots of coal is burned in one area. It's a mix of smoke and a gas called sulfur dioxide. This type of smog was common in cities like London a long time ago.

Photochemical Smog

This kind of smog is more common today. It forms when sunlight reacts with gases from things like car exhaust fumes and factories. Cities like Los Angeles often have this type of smog.

Smog Around the World

Smog is a big problem in many cities across the globe.

London's History with Smog

London was one of the first places to experience severe smog. In the past, people burned a lot of coal in their homes and trains. This caused thick, dark smog that was very dangerous. Today, burning coal in homes is against the law in London, and trains use different fuels. This has made the air much cleaner.

Smog in Modern Cities

• Delhi, India: This city is known for having some of the worst air pollution in the world. Smog here is caused by many things, including car exhaust and the burning of farm waste. It's estimated that air pollution causes thousands of deaths in Delhi every year.
• Beijing, China: Air pollution is also very serious in Beijing. Car emissions and burning coal are the main reasons. Sometimes, pollution also blows in from nearby areas because of how the air moves.
• Los Angeles, USA: This city often has photochemical smog, mainly from the many cars on its roads.

How Smog Affects Us

Smog is not just ugly; it's also very bad for our health and the environment.

Health Problems

Breathing in smog can cause serious lung diseases. It can make it hard to breathe, especially for children, older people, and those with asthma. Smog can also increase the death rate in cities because it makes people sick.

Environmental Impact

Smog can harm plants and crops. It can also make the air hazy, reducing visibility and making it harder to see things like mountains or city skylines.

Images for kids

• 

  The photochemical smog formation diagram. (Based on U 6.3.3 in mrgsciences.com)

• 

  Airplane used to collect airborne hydrocarbons, May 1972

• 

  The presence of smog in California is shown near the Golden Gate Bridge. The brown coloration is due to the NO2 formed from photochemical smog reactions.

• 

  During the autumn and spring months, some 500 million tons of rice and wheat crop residues are burnt, and winds blow from India's north and northwest towards east. This aerial view shows India's annual crop burning, resulting in smoke and air pollution over Delhi and adjoining areas.

• 

  Dense smog blankets Connaught Place, New Delhi

• 

  Victorian London was notorious for its thick smogs, or "pea-soupers", a fact that is often recreated (as here) to add an air of mystery to a period costume drama

• 

  Grease filter hood after 4 days at Italian city polluted air in winter (all surface was white)

• 

  Situated in a valley, and relying heavily on automobiles, Mexico City often suffers from poor air quality.

• 

  Photochemical smog over Mexico City, December 2010

• 

  A NASA astronaut's photograph of a smog layer over central New York

• 

  View of smog south from Los Angeles City Hall, September 2011

• 

  Counties in the United States where one or more National Ambient Air Quality Standards are not met, as of October 2015

• 

  Singapore's Downtown Core on 7 October 2006, when it was affected by forest fires in Sumatra, Indonesia

• 

  Smog in São Paulo, Brazil

See also

In Spanish: Esmog para niños