Smog is a type of air pollutant; the word "smog" is a combination of smoke and fog. Classic smog results from large amounts of coal burning in an area and is caused by a mixture of smoke and sulfur dioxide.
Delhi is supposed to be the most polluted city on Earth. Smogs cause lung diseases and increase the death rate. According to one estimate, air pollution causes the death of about 10,500 people in Delhi every year.
Peking (Beijing) is another city where air pollution is serious. Car emissions and coal burning are the main reasons for their pollution. They also get pollution from some neighbouring regions, due to the pattern of air movement in the area.
- "Delhi is most polluted city in world, Beijing much better: WHO study". Hindustan Times. Retrieved 8 May 2014. CS1 maint: discouraged parameter (link)
- "Delhi's air has become a lethal hazard and nobody seems to know what to do about it". Time magazine. Retrieved 10 February 2014. CS1 maint: discouraged parameter (link)
- "India's air pollution triggers comparisons with China". Voice of America. Retrieved 20 February 2014. CS1 maint: discouraged parameter (link)
- "A Delhi particular". The Economist. Retrieved 6 November 2012. CS1 maint: discouraged parameter (link)
- J.R. McNeill 2000. Something new under the Sun: an environmental history of the 20th-century world. New York: Norton, 2000, ISBN 978-0-14-029509-2.