May 25, 2016

According to a World Health Organization (WHO) survey released earlier this month, billions of city dwellers throughout the world experience unhealthy levels of air pollution. WHO is an agency of the United Nations that helps build better health systems throughout the world, especially in developing countries. The WHO survey reported on air quality data from 3,000 cities around the world. The most severe air pollution conditions were found in some of the world’s poorest regions, but the report also showed problematic air pollution in wealthy nations. The WHO report found that about 80 percent of the world’s urban citizens are exposed to dangerous levels of air pollution daily.

Smog obscures residents of Fuyang, a city in China’s Anhui Province, during morning excercises. A recent report estimated that 80 percent of the world’s cities have unhealthy levels of air pollution. Credit: © Imaginechina/AP Photo

Air pollution is a serious problem worldwide. When people breathe polluted air, the impurities can irritate their air passages and lungs. Particulates (small particles) often remain in the lungs, and they can worsen such respiratory ailments as asthma and bronchitis. Air pollution, including smog, soot, and ozone, reduces resistance to colds and pneumonia and can aggravate emphysema. Carbon monoxide interferes with the transfer of oxygen from the lungs to body tissues.

Compared to data gathered in similar reports over many decades, this newest WHO survey shows that air quality has rapidly declined in most cities across the world. This is especially true for cities in developing nations, where infrastructure improvements have not kept up with rapid population growth, especially among the poor. Increasingly, cities are becoming polluted with smog and soot from cars and other transports, industry, construction sites, farming, and wood-burning stoves. Fast-growing cities in the Middle East, Southeast Asia, and the western Pacific are the most impacted, with many showing pollution levels at 5 to 10 times above recommended levels.

Onitsha, a fast-growing port city in southeastern Nigeria, has the world’s worst air quality according to the WHO report, while 16 of the 30 most polluted cities are found in India. Air pollution levels were found to be generally lower for cities in developed countries, but unhealthy levels were frequently recorded in London, New York City, and Sydney, Australia. The purest air was reported in Muonio, a small city in Finland about 95 miles (153 kilometers) north of the Arctic Circle. Other cities noted for especially clean air included Norman Wells in Canada and Campisábalos, Spain.

January 22, 2013

The Supreme Court of the United States confirmed today that the Environmental Protection Agency (EPA) has the authority to set air quality standards. The court’s decided, without comment, not to hear an appeal by the Asarco Corporation of a July 2012 decision by the Washington, D.C., Circuit Court of Appeals that upheld the EPA’s new national ambient air quality standard for sulfur dioxide. Asarco, a unit of Grupo Mexico SAB, operates one of the three main copper smelters in the United States. By refusing to hear the appeal, the court upheld the lower court’s decision that the EPA has the authority under the Clean Air Act to adopt standards that are necessary to protect public health.

The Supreme Court has ruled that the Environmental Protection Agency has the authority to set air quality standards. (© Joe Sohm, Photo Researchers)

Exposure to sulfur dioxide, which typically is produced by the burning of fossil fuel at electric power generating plants and other industrial facilities, has been linked to respiratory illnesses. The 2010 EPA rule limits sulfur dioxide in the air to 75 parts per billion over a one-hour period. Asarco claims that it will cost as much $1.5 billion to bring its Hayden, Arizona, smelter into compliance with the 2010 rule.

Additional World Book articles:

• Air pollution
• Environmental pollution
• Environmental pollution 2010 (a Back in Time article)