Lopez

Abstract:
Air pollution may be described as contamination of the atmosphere by gaseous, liquid, or solid wastes or by-products that can endanger human health and welfare of plants and animals, attack materials, reduce visibility or produce undesirable odors. Although some pollutants are released by natural sources like volcanoes, coniferous forests, and hot springs, the effect of thispollution is very small when compared to that caused by emissions from industrial sources, power and heat generation, waste disposal, and the operation of internal combustion engines. Fuel combustion is the largest contributor to air pollutant emissions, caused by man, with stationary and mobile sources equally responsible. The air pollution problem is encountered outdoor as well as indoor.

Outdoorair pollution is caused by small particles and ground level ozone that comes from car exhaust, smoke, road dust and factory emissions. Outdoor air quality is also affected by pollen from plants, crops and weeds. Particle pollution can be high any time of year and are higher near busy roads and where people burn wood.
When inhaled, outdoor pollutants and pollen can aggravate the lungs, and canlead to chest pain, coughing, digestive problems, dizziness, fever, lethargy, sneezing, shortness of breath, throat irritation and watery eyes. Outdoor air pollution and pollen may also worsen chronic respiratory diseases, such as asthma. When people think about air pollution, they usually think about smog, acid rain, CFC's, and other forms of outdoor air pollution. But did you know that airpollution also can exist inside homes and other buildings? It can, and every year, the health of many people is affected by chemical substances present in the air within buildings. A great deal of research on pollution is being conducted at laboratories and universities.
Almost 160 million persons live in areas of the United States that exceed federal health-based air pollution standards. The two airpollutants that most commonly exceed standards are ozone and particulate matter. Ozone and particulate matter can harm anyone if levels are sufficiently elevated, but health risk from air pollution is greatest among vulnerable populations. Both ozone and particulate matter can cause pulmonary inflammation, decreased lung function, and exacerbation of asthma and chronic obstructive pulmonarydisease. Particulate matter is also strongly associated with increased cardiovascular morbidity and mortality. Children, older adults, and other vulnerable persons may be sensitive to lower levels of air pollution. Persons who are aware of local air pollution levels, reported daily by the U.S. Environmental Protection Agency as the Air Quality Index, can take action to reduce exposure. These actionsinclude simple measures to limit exertion and time spent outdoors when air pollution levels are highest, and to reduce the infiltration of outdoor air pollutants into indoor spaces.
Despite steady improvements in air quality in recent decades, 2007 data indicate that more than one half of all persons in the United States live in areas where levels of outdoor air pollution exceed health-basedstandards.1 Air pollution levels tend to be highest in urban areas, but rural areas may also be affected. The U.S. Environmental Protection Agency (EPA) and other regulatory agencies focus on reducing air pollution at its many sources. Physicians and patients can use the EPA's daily Air Quality Index (AQI) to take action to mitigate related health risks.
Despite the lack of evidence of improvementin outcomes from prospective studies, consensus guidelines recommend that physicians help patients use AQI information to reduce personal exposure to air pollutants and subsequent health effects. Vulnerable patients include children and older adults, as well as persons with asthma, chronic obstructive pulmonary disease (COPD), or heart disease.2 Improvements in air quality have led to measurable...