From 1990 to 2010 as reported in February 2012 by the US Environmental Protection Agency (EPA) in EPA. 2012. Our Nation’s Air: Status and Trends through 2010. EPA. Washington DC, there has been a substantial improvement in reducing air pollution and increasing air quality. (See endnote 82.) This has been due to cleaner cars, cleaner industries, and the improved production of consumer products. The six common air pollutants are in decline as well as many of the toxic air pollutants. However, approximately 124 million people live in counties in the United States that exceed one or more of the National Ambient Air Quality Standards (NAAQS). (See endnote 58.)
There are still considerable problems with ground-level ozone and particulate pollutants, which are present in unhealthy amounts in many areas of the country. These pollutants can affect the cardiovascular system, cause premature death, and increase both emergency room and hospital admissions because of heart attacks and strokes.
Air toxics continue to be a problem especially in urban areas, around industrial facilities, and high levels of transportation. Small area sources continue to add to the overall volume of air toxics present.
Air pollution problems in one part of the country may be caused by industries in other parts of the country and therefore simply improving local situations may not be enough to achieve attainment areas. The taller smokestacks can move the pollutants into wind currents that can help them go hundreds or thousands of miles and contribute to smog, haze, and other air pollution episodes. The US EPA, although having made considerable progress in smokestack emissions control, is continuing to bring enforcement actions against large refineries, coal-fired power plants, cement manufacturing facilities, sulfuric acid and nitric acid manufacturing facilities, and glass manufacturing facilities for inadequate compliance with EPA regulations and the Clean Air Act.
International sources of air pollution, especially from China, are having an effect on the Western United States by increasing levels of ozone, mercury, sulfur, carbon monoxide, and other pollutants including very fine carbon particles carrying a variety of toxic substances. At present, these contaminants come from fumes and dust from industrial factories, energy sources created from coal, and the increased use of automobiles. Further, about a third of the pollution coming from Asia is dust which may in part be due to drought and deforestation. In part, it is due to the use of fossil fuels as economies improve and industrialization increases in scope. The air pollution in Beijing, China, was so intense before, during, and after the Summer Olympics of 2008 that there was major media coverage and an unusual level of concern by the International Olympic Committee.
Internationally, there is a concern for people in developing countries who live near resource extraction and processing industries, as well as in big cities, who are subjected to dust or hazardous fumes at the work site as well as in their homes. Many of the problems affecting the industrialized societies have now been transferred to the resource-rich Third World countries that are having difficulty coping with them. Cardiovascular and respiratory diseases have increased substantially with exposure to the additional particulate material which is now airborne. There is an increase in lung cancer and lung cancer deaths. There is increased mortality in children from air pollutants and the ozone exposure has triggered asthma attacks. Leaded gasoline is still a major factor in urban areas. The World Health Organization in 2002 estimated that in urban areas particulate matter caused as many as 5% of the global cases of lung cancer, 2% of the deaths from cardiovascular and respiratory conditions, and 1% of the respiratory infections. China and India are the two most affected countries. There have been signs of changes in learning ability, behavioral changes, and central nervous system damage from the increased amount of lead present in the air. (See endnote 9.)