Myths and Facts
About the Environment --
Part III: Urban Air Pollution and Smog

Myth: Smog is caused exclusively by human activity.

Fact: Both carbon monoxide and ground-level ozone (the two main components of smog) are created naturally, as well as by humans. Carbon monoxide is created by any burning of organic materials, and ground-level ozone forms when carbon dioxide and nitrogen oxides (which are produced naturally) are combined at a temperature of 90 F or higher.

Myth: Air pollution and smog cause urban areas to be warmer than surrounding areas.

Fact: Urban areas are warmer than surrounding areas due to their construction. Light is absorbed and reflected differently by asphalt and concrete than it is by green vegetation, resulting in higher urban temperatures.

Myth: Ground-level ozone is steadily increasing.

Fact: A study by Michigan State University suggests that the patterns and levels of ground-level ozone were the same back in 1871. This study was based on measurements taken between 1871 to 1903, from 20 recording stations throughout Michigan.

Myth: Urban air pollution increases the risk of lung cancer in humans.

Fact: No correlation has been found between urban air pollution and lung cancer. The countries with the highest rates of urban pollution do not have the highest rates of urban lung cancer, and lifetime urban residents do not have a higher rate of lung cancer than migrants to urban areas.

Information from Environmental Overkill by Dixy Lee Ray (Regnery Gateway, 1993).

Issue Date: August 20, 1996

Talking Points on the Economy: Environment #24, published by The National Center for Public Policy Research, 501 Capitol Ct NE, Washington, D.C. 20001 Tel. (202) 507-6398, Fax (301) 498-1301, [email protected], http://www.nationalcenter/ For more information about Talking Points on the Economy: Environment #24 contact Bob Adams at (202) 507-6398 or [email protected]

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