Air Quality Index (AQI) Values) When the AQI is in this range:	Levels of Health Concern	Colors
0-50	Good	Green
51-100	Moderate	Yellow
101-150	Unhealthy for Sensitive Groups	Orange
151 to 200	Unhealthy	Red
201 to 300	Very Unhealthy	Purple
301 to 500	Hazardous	Maroon

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A GUIDE TO AIR QUALITY & HEALTH BROCHURE - AIR NOW

Science Daily: Ozone Levels May Raise Risk Of Underweight Births

Understanding the AQI

The purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:

Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:

"Good" AQI is 0 - 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
"Moderate" AQI is 51 - 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.
"Unhealthy for Sensitive Groups" AQI is 101 - 150. Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air. .
"Unhealthy" AQI is 151 - 200. Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects. .
"Very Unhealthy" AQI is 201 - 300. This would trigger a health alert signifying that everyone may experience more serious health effects.
"Hazardous" AQI greater than 300. This would trigger a health warnings of emergency conditions. The entire population is more likely to be affected

SOURCE: AIR QUALITY NOW WEBSITE

AQI colors

EPA has assigned a specific color to each AQI category to make it easier for people to understand quickly whether air pollution is reaching unhealthy levels in their communities. For example, the color orange means that conditions are "unhealthy for sensitive groups," while red means that conditions may be "unhealthy for everyone," and so on.

AIR QUALITY ALERT DAY - AUGUST 3, 2011

ANOTHER AIR QUALITY ALERT DAY - AUGUST 2, 2011

Forecast: Fog early, hot, air quality alert

By News Sentinel staff

Friday, July 29, 2011

KNOXVILLE — Commuters will encounter some patchy fog early this morning across East Tennessee.

It will burn off quickly as temperatures rise into the mid-90s with heat index values near 100 degrees.

Additionally, a code orange air quality alert has been issued for much of the region. The alert means that ground-level ozone levels may reach or exceed unhealthy standards.

The Knoxville-area forecast for today calls for a 20 percent chance of showers and thunderstorms, mostly sunny skies with a high near 94 and heat index values as high as 99.

Overnight will be mostly cloudy with a 20 percent chance of showers and thunderstorms, low around 71.

A 50 percent chance of showers and thunderstorms is possible Saturday with partly sunny skies, high near 93, heat index values as high as 100.

A 30 percent chance of showers and thunderstorms extends into Saturday night with mostly cloudy skies and low around 72.

Sunday will be partly sunny and hot, high near 93, 40 percent chance of showers and thunderstorms, low around 71.

Monday through Wednesday will be mostly sunny and hot, highs in the low 90s, lows in the upper 60s to near 70.

A 20 percent chance of showers and thunderstorms returns to the forecast Thursday under partly sunny skies, high near 94.

JULY 4TH CODE ORANGE DAY

knoxnews.com

Forecast: Code-orange air quality alert, scattered showers, thunderstorms

By News Sentinel staff

Monday, July 4, 2011

KNOXVILLE — A code-orange air quality is in effect for much of Independence Day in East Tennessee, including Knoxville, the the Smokies, Tri-Cities and Chattanooga.

The alert means that ground-level ozone concentrations may approach or exceed unhealthy standards, causing problems with sensitive groups.

Later today a weak cold front approaching the Southern Appalachian region will trigger scatter showers and thunderstorms, some of which may be severe with damaging winds, large hail and locally heavy rainfall.

This stationary front will linger in the Tennessee Valley for several days while another weak cold front will approach the region Thursday. These fronts may produce severe storms daily.

The Knoxville-area forecast for today calls for about a 60 percent chance of showers and thunderstorms this afternoon. Otherwise it will be partly sunny and hot with a high near 92. Overnight a 40 percent chance of scattered showers and thunderstorms is possible with a low around 69.

Rain is possible the rest of the week through Sunday with the best chance overnight Tuesday.

Tuesday’s forecast calls for a 40 percent chance of showers and thunderstorms with a high near 91. A 50 percent chance of rain is possible overnight with a low around 68.

A 40 percent chance of showers and thunderstorms is possible Wednesday with partly sunny skies, high near 92, low around 68.

Thursday will see a 30 percent chance of showers and thunderstorms in the afternoon with partly sunny skies, high near 91, low around 69.

It will be partly sunny and hot Friday with a 40 percent chance of showers and thunderstorms, high near 91, low around 68.

A 30 percent chance of showers and thunderstorms is possible Saturday with a high near 92, low around 70.

Sunday’s high will be near 94 with a 40 percent chance of showers and thunderstorms under partly sunny skies.

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