Facts of the Matter -- Air pollution

Smog, Laura Bond, United Kingdom

A ir pollution has been a matter of public awareness and concern for centuries. In AD 61, the Roman philosopher Seneca wrote about the “heavy air” and “pestilential vapors” of Rome. In 1306, King Edward I of England issued a proclamation banning the use of sea coal in London because of the smoke it caused.

• In December 1952, a cold front settled over London. As residents tried to keep warm by adding extra coal to their fireplaces, the smoke – combined with emissions from factories and coal-burning power plants – created smog that did not dissipate for five days. Over the next few months, nearly 12,000 people died from respiratory disorders related to what became known as the Great Smog. It led to the passage of laws in England regulating emissions of black smoke and requiring the use of cleaner-burning fuels.
• A similar event took place in October 1948 in the river valley steel town of Donora, Pa., USA. Twenty people died, and 7,000 became ill. The investigation into the Donora Smog Disaster led to the passage of the Air Pollution Control Act in 1955, which set aside $5 million annually for research by the Public Health Service. In 1963, Congress passed the Clean Air Act, attempting to reduce air pollution by setting emissions standards for power plants and steel mills. In 1970, the Environmental Protection Agency (EPA) was created through an executive order by President Richard M. Nixon.
• The EPA tracks and has set standards for six common air pollutants: carbon monoxide (CO), lead (Pb), ground-level ozone (O ₃ ), nitrogen dioxide (NO ₂ ), particulate matter (PM), and sulfur dioxide (SO ₂ ). The World Health Organization established new air quality guidelines in 2005 that focus on four of them: ozone, nitrogen dioxide, particulate matter, and sulfur dioxide. 
• WHO estimates that air pollution causes two million premature deaths each year. It is related to more than half of the health problems in developing countries. Annually, about 1.6 million deaths are attributable to indoor air pollution, the result of more than half the world’s population relying on the burning of coal, crop waste, dung, and wood for heating and cooking.
• According to a report by the Blacksmith Institute in 2007, the places with the worst air pollution in the world are Mexico City; Magnitogorsk, Russia; and Lanzhou, Linfen, and Urumqi, China.
• The first international cooperative effort to protect the stratospheric ozone layer – not the lower atmosphere, where ozone is a harmful pollutant – was the Vienna Convention for the Protection of the Ozone Layer in 1985. Details of that agreement were defined in the Montreal Protocol on Substances that Deplete the Ozone Layer, which has been ratified by nearly 200 countries and aims to phase out the use of damaging substances.