Jason VanMeetren
Trade & Environment: Energy, the Political and Environmental Crisis of the Next Millenium
March 8, 1999

Smog is a mixture of solid and liquid fog and smoke particles formed when humidity is high and the air so calm that smoke and fumes accumulate near their source.  Smog is caused by a number of different pollutants and has some rather serious negative effects on people, animals, and plant life. Dense urban areas suffer the worst from smog specifically during prolonged periods of heat inversion that often create a smog-trapping ceiling over a city. 

Los Angeles, California has the highest smog levels in the nation and unfortunately serves as an example of how dangerous smog can be. Rep. Henry A. Waxman asked the minority staff of the Committee on Government Reform of the U.S. House of Representatives to investigate the public's exposure to hazardous air pollutants in Los Angeles. This congressional staff report presents the results of this investigation. It finds that many residents of Los Angeles may be exposed to levels of hazardous air pollutants that are hundreds of times higher than the goals of the Clean Air Act[i].  In a recent study done by the US Clean Air Network, Los Angeles was recognized to have had at least 79 days classified as unsafe due to high smog levels last year2.   However, because Los Angeles has such high smog levels, the city can also be useful in understanding how Americans can avoid such dangerous smog levels in the future.    Using Los Angeles as a model one can better understand the activities that cause smog, the risks that appear as a result of smog, and the ideas available to help reduce smog levels in America and throughout the world.




The main activities that cause smog in America can be classified into three main categories. Stationary sources such as chemical plants and oil refineries, mobile sources like automobiles, diesel trucks, trains, and airplanes, and smaller sources like utility plants. The Environmental Protection Agency provides a National Toxins Inventory that estimates emissions of hazardous air pollutants from various sources.  Throughout America, large stationary sources, account for 61% of all hazardous air pollutant emissions, while mobile sources and smaller area sources contribute 21% and 18% respectively.3


The most significant source of pollution in the Los Angeles area comes from the internal-combustion engines of motor vehicles. They are estimated to be responsible for 60% of the pollution in California.  Commercial equipment, aircraft, trains, and diesel trucks make up 10% of the pollution, while on-road motor vehicles and motorcycles are responsible for the remaining 50%.

The primary reason is that Americans are driving more than ever. Since 1970 the number of miles driven in America each year has grown 300%, from 1 trillion to 3 trillion miles. Another reason is that many more Americans are choosing to drive minivans, sport-utility vehicles, and small trucks, which burn more fuel and have much higher emissions. Today light trucks and Sport Utility Vehicles s make up 46% of the vehicle market, compared with 20% in 1980.


Stationary sources are also dangerous producers of Smog.  The tall smokestacks used by industries and utilities do not remove pollutants but simply boost them higher into the atmosphere, thereby reducing their concentration at the site. These pollutants may then be transported over large distances and produce adverse effects in areas far from the site of the original emission. Sulfur dioxide and nitrogen oxide emissions from the central and eastern U.S. are causing acid rain in New York, New England, and eastern Canada. The pH level, or relative acidity, of many freshwater lakes in that region has been altered so dramatically by this rain that entire fish populations have been destroyed. Sulfur dioxide emissions and the subsequent formation of sulfuric acid can also be responsible for the attack on limestone and marble at large distances from the source.




Under the 1990 Clean Air Act, 188 chemicals have been designated as hazardous air pollutants because of their potential to cause adverse environmental and health effects. The quantification of health risks from exposure to hazardous air toxins is an imprecise science.  No one is sure how much exposure to any particular element of smog will result in damage.  However, smog is directly responsible for many health risks. Smog reduces natural visibility and often irritates the eyes and respiratory tract. Furthermore, the congressional staff report of the Committee on Government Reform of the U.S. House of Representatives, showed that due to the high smog levels, Los Angeles citizens are exposed to cancer risks higher than the Clean Air Act recommends.  In fact, Citizens were exposed to nearly five times the recommended levels of such chemicals as butadiene, formaldehyde, and benzene, all of which contain cancer-causing carcinogens. The findings in this report are based on data from three air quality monitors operated in Los Angeles from 1995 to 1998. These data contain over 2,000 monitoring results collected for ten hazardous air pollutants. While previous reports have discussed the level of emissions of hazardous air pollutants in Los Angeles, this is the first report to reveal the concentrations of these pollutants in the ambient air based on recent monitoring data. It is also the first report to estimate the potential health risks from exposure to these hazardous air pollutants. In addition, smog contains pollutants such as Sulfur dioxide, the main component in the formation of acid rain. 4Photochemical smog, caused when sunlight radiations react with nitrogen oxides, is proven to damage plant life and irritate sensitive membranes of both people and animals.5




Smog reduction requires control of smoke from furnaces, reduction of fumes from metalworking, utility, and other industrial plants, along with the control of noxious emissions from automobiles, trucks, and incinerators. In the U.S., the Clean Air Act of 1967 as amended in 1970, 1977, and 1990 is the legal basis for air-pollution control throughout the U.S. The Environmental Protection Agency (EPA) has primary responsibility for carrying out the requirements of the act, which specifies that air-quality standards be established for hazardous substances. These standards are in the form of concentration levels that are believed to be low enough to protect public health. Source emission standards are also specified to limit the discharge of pollutants into the air so those air-quality standards will be achieved. The act was also designed to prevent significant deterioration of air quality in areas where the air is currently cleaner than the standards require. On the international scene, 49 countries agreed in March 1985 on a United Nations convention to protect the ozone layer. This “Montreal Protocol,” which was renegotiated in 1990, calls for the phaseout of certain chlorocarbons and fluorocarbons by the year 2000 and provides aid to developing countries in making this transition.

The technology to reduce smog is available, but many advancements have not been utilized or are just recently being put into effect.  Most cars on road in the U.S. today are much cleaner than the1970's models.  However, given the vast technological advances in the last decade, cars still pollute many times more than is necessary.  Fortunately, some states are taking steps in the right direction.  California, for example, recognized that they have a smog problem and have implemented tougher automotive standards. The California Low-Emission Vehicle (LEV) program requires that automobiles sold in California meet emissions standards for hydrocarbon emissions that are more stringent than the comparable EPA standards. While the federal standard for NOx is 0.4 grams/mile, currently California cars meet a standard of .2 grams/mile, and the state is proposing to reduce the levels to .05grams/mile in the next phase of their low emission vehicle program. In California, automakers have developed cars that have zero or near-zero emissions. These cars are being sold not only in California, but also in New York, Massachusetts, Vermont and Maine today, and in some cases at no increased cost. Beginning in 2003, 10 percent of the cars sold must be electric or other zero-polluting cars in California and in the four Northeast states that have adopted the California program. 6


In the mean time, several other ideas have been introduced to aid in the prevention of smog from vehicles. Some of the most popular are public transportation carpooling; both serve a practical ways that everyone can help to reduce smog.  The vehicle retirement program and the welfare to work project are two new projects that have proven to be useful in the control of smog pollution in California.  The vehicle retirement program was designed by the Bureau of Automotive Repair (BAR) and offers California vehicle owners the opportunity to retire vehicles that fail a biennial Smog Check.  The BAR will even pay $450 for each vehicle that is accepted into the retirement program.  The Welfare to Work Project sponsors welfare recipients to become trained to perform various automotive repair shop functions. These functions include emissions inspections and maintenance tasks that help prevent smog while providing real world training and experience to the workers.

The city of Los Angeles is very valuable because of the lessons we can learn from it.   Smog is a serious problem facing America today, and one that effects all of us. By learning about the sources that cause smog, the risks that occur as a result of smog, and what can be done to reduce smog levels, we see that the problem of smog is not impossible to control. Smog level reduction is a realistic and obtainable goal that and can be achieved if everyone does his or her part to help.










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