Atmosphere And Weather

How is Air Quality Measured

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"How is Air Quality Measured"
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Air quality is an important factor today, not only for the protection of those who live and breath the air, but as an indicator as to how well we are doing in decreasing pollution in the atmosphere. Every day concentrations of air are measured to determine what pollutants are present, and in what amounts. Individual states and cities monitor their air and compare the results to federal standards, through the Environmental Protection Agency’s Air Quality Index, AQI.

The AQI is a guide for reporting the quality of air on a daily basis. It immediately detects possible harmful pollution and its health effects that may impact people in the area within a few hours or days after exposure. The more common pollutants that are recorded and regulated are ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. The EPA has established standards to protect against harmful health effects for each of these. The AQI index runs from 1-500, and the higher a certain possible pollutant ranks after being tested, the more dangerous the toxicity level is. A reading of 100 is the national average for accepted air quality, and anything over that is considered unhealthy. Each pollutant is monitored throughout the day, and the information recorded and translated into the AQI index.

0-50 on the scale is considered extremely good, and the color on the chart is indicated in green. 51-100 is considered moderate. At this level, those who are very sensitive should wait until the quality of the air is better before planning outside activities. Color on chart is yellow. 101-150 is unhealthy for sensitive people, and even those who are not should limit outside activities. Color indicator is in red.151-200 is unhealthy. Everyone should cut back on strenuous activities outside. Color on chart is purple. The highest level is 201-300 and this is considered very unhealthy. All people, but especially the elderly, children, people with existing health problems, and those who work or exercise outdoors should avoid being outside for any length of time. Color indicated in maroon.
Air quality testing is required in most areas on a daily basis and is available in newspapers, on the net, or on TV. The charts showing areas nationally, and how they rank on the AQI will be shown by the colors, representing each individual level.

Not all people, of course, will be affected by the same pollutants, so there will be exceptions to the rules, however, keeping track of pollutants helps to prevent future health problems, and also gives communities a better idea of which areas to concentrate on in their efforts to clear the air.

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