Air Pollution Trends

For the most part, the air over the United States has gotten cleaner since the Clean Air Act was passed in 1970. Figures published by the Environmental Protection Agency (EPA), show that between 1970 and 2003 the population of the United States grew by 39%, the gross domestic product (GDP) increased by 176%, vehicle miles traveled increased by 155%, and energy consumption increased by 45%. Yet, during this period, emissions of the six major pollutants (carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates) dropped by 51%, and the total emission of toxic chemicals declined as well. The best success has been with lead; its gradual elimination from gasoline resulted in its near absence from emissions. For the acid rain producing compounds, sulfur dioxide (SO2) fell 54% between 1983 and 2002, including a decrease of 39% over the more recent 10-year period of 1993 to 2002. Nitrous oxides (NOx) increased by almost 17% from 1982 to 2001, but decreased 3% between 1992 and 2001. Improvements in SO2 and NOx emissions are attributed primarily to controls implemented under the EPA's Acid Rain Program, which began in 1995.

Many regions of the United States, including most urban and industrial regions, have seen great improvements in air quality. Despite this incredible progress, the air over much of the country is not yet clean. Many regions do not meet the standards of the Clean Air Act Amendment of 1990; there are too many cars, too much construction, and too much industry. Pollutants, both visible and invisible, continue to cause health risks to people and the environment.

California has led the way in air pollution control and the federal government has followed. California state bureaucracies lowered auto emissions standards in 1975, which meant that California cars needed catalytic converters two years before they were required in the rest of the country. The state eliminated lead from gasoline before it was required by the federal government, and put scrubbers and other pollution control devices on oil refineries and power and industrial plants. The South Coast Air Quality Management District monitors and regulates emissions from every other possible source, including dry cleaners, barbeque lighter fluid, and oil-based paints.

uccess Story

Between 1980 and 2005, Southern California's population grew by 60% and the number of cars doubled, according to an August 3, 2005, article in the New York Times. In that time, nitrogen oxides decreased by about two-thirds and carbon monoxide fell to about 20%. Data provided by the South Coast Air Quality Management District shows that the number of days the 8-hour ozone average exceeded federal standards dropped from 186 to 84. Extreme ozone events decreased too; in 1978, Southern California experienced 116 Stage I smog alerts and 23 Stage II smog alerts. In 2005, there were no ozone alerts at all. In fact, between 1999 and 2005 there was only one Stage I alert (in 2003); the last Stage II alert was in 1988.

Even though incredible progress has been made, residents of the Los Angeles Basin breathe dirty air on approximately one-third of the days each year. The relatively low levels of ozone are high enough to have health effects, particularly in children. A 10-year study released in 2004 of active children growing up in the Los Angeles basin revealed that those living in the worst areas for ozone had lung capacity of 10% to 20% less than those in areas with lower ozone levels. The study was headed by Dr. John Peters of the Keck School of Medicine of the University of Southern California in Los Angeles. In that

New York Times article of August 3, 2005, Peters said, "The statistics would show that you're going to die younger and be more likely to have more heart and lung disease."

The air in the Los Angeles Basin is getting worse again, at least in some areas. A growing source of pollution is the Port of Los Angeles, which receives 40% of the goods that come into the United States by ship. To pick up these goods, an average of 35,000 trucks visits the port each day. The ships, trucks, and heavy machinery at the port all run on highly polluting diesel fuel. Federal regulations put into place so far control only new, less-polluting engines. The older trucks, ships, and heavy machinery, which operate under the old standards, will continue to emit excess pollutants for many more years. The largest source of diesel particulates is ships, but they are difficult to regulate since they are governed by international law. Local attempts are being made at cleaning up these pollution sources, and any cleanup will happen none too soon. In Long Beach, a city located northeast of the ports, the cancer risk is twice that of west-central Los Angeles, and four times that in the mountains above the breezy Pacific Ocean. Particulates from diesel fuel account for 70% of the cancer risk.

Global trends in air pollution are mixed. In Europe, emissions of most pollutants are down and continuing to decline. In Asia, emissions are up tremendously; for example, emissions of NOx approximately tripled between 1975 and 1997. The steep rise will continue as Asian countries work to improve their standard of living and, in doing so, burn more fossil fuels. Biomass burning, particularly of tropical rainforests, is increasing rapidly as well.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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