Ozone Action Days
Planning & Air Quality Analysis Branch
Tony Davis, Branch Manager - (501) 682-0728
"Air Quality is a Priority in the Natural State"
Throughout the May through September "Ozone Season",
ozone forecasts for the Little Rock/North Little Rock Metropolitan Statistical
Area (MSA) are conducted on a daily basis. This MSA area includes Pulaski,
Saline, Faulkner, and Lonoke Counties.
For air quality information throughout the entire year
the ADEQ Air Quality Index (AQI), a measure of overall
air quality that identifies the most significant air pollutant for the day,
is reported by ADEQ's Technical Services
Division on weekdays.
Air quality is variable and dependent upon a number of factors including; sunlight,
temperature, wind speed and direction. Like the weather, it can change from day
to day or even hour to hour. The U.S. Environmental Protection Agency (EPA) and
others are working to make local air quality information as available to the public
as weather information. Ozone Action Days is our local central Arkansas program
coordinated through Metroplan and the Central Arkansas Clean Cities Coalition in
cooperation with the Arkansas Department of Health (ADH), Arkansas Department of
Environmental Quality (ADEQ), and the Arkansas Highway and Transportation Department
(AHTD). Counties included in the program are Pulaski, Faulkner, Lonoke and Saline.
Air pollution affects everyone. Every day, the average adult breathes over 3,000
gallons of air. Children breathe even more air per pound of body weight and are
thus more susceptible to air pollution. Children are even at a greater risk than
adults because they are more active outdoors and their lungs are still developing.
The elderly are more sensitive than healthy adults to air pollution because senior
citizens often have heart or lung disease. When people have a short-term exposure
to air pollutants above certain levels, they may experience temporary health concerns,
such as eye irritation and burning, throat irritation, and difficulty breathing.
Long-term exposure to air pollution can cause chronic health concerns, such as cancer
and damage to the body's immune, neurological, reproductive, and respiratory systems.
Since the inception of the Ozone Action Days program in 1998, the participating
agencies have worked to increase public awareness of ozone related health risks
and ways to reduce ozone precursor emissions. "Ozone Action Alerts" are
declared when ozone forecasts have indicated the next day’s conditions could support
the formation of high concentrations of ground level ozone. The Ozone Action Days
program emphasis is on providing notification about the predicted high ozone episodes
with suggestions for voluntary actions to protect public health, especially those
populations identified as most at risk and ways in which individuals and groups
can work to reduce the production of nitrogen oxides and volatile organic compounds
released into our air.
The air quality professionals of the ADEQ Air Division Planning and Air Quality
Analysis Branch create the daily ozone forecast. Several external resources and
tools are used in support of these forecasts. Little Rock’s
National Weather Service Forecast Office provides current meteorological condition
and next day meteorological forecasts that provide valuable input into decision
trees and statistical analysis processes.
Ozone monitors throughout
the state provide the real-time ozone data for use in forecasting and also supply
the data to produce AIRNow’s animated ozone maps. Please access the daily
ozone forecast and incorporate the health protection recommendations into your plans
for the following day. Remember that ozone forecasting is a prediction of tomorrow’s
ground level ozone concentrations. While the ozone forecasters do their best to
be as accurate as possible, because it is a prediction, occasionally they are incorrect.
As of Ozone Season 2000, ozone forecasts for the Little Rock/North Little Rock
MSA have been posted on ADEQ’s website and EPA’s AIRNow website each day from May
through September. Arkansas’ Ozone Action Days program and 165 other cities across
the United States use the format of EPA's Air Quality Index (AQI) to clearly display
predicted ozone levels. The AQI format focuses on the health effects of breathing
polluted air. The AQI is like a yardstick that runs from 0 to 500. The higher the
AQI value, the greater the level of air pollution and health risk. A specific color
has been assigned to each AQI category to make it easier for people to quickly understand
the significance of air pollution levels. By 3:00 p.m., the daily ozone forecast
is posted on this Web page.
Ozone Action Day Alerts and Advisories are issued when ground-level ozone concentrations
in the Little Rock/North Little Rock MSA are forecast to be in exceedance of the
National Ambient Air Quality Standards (NAAQS).
http://www.epa.gov/ttn/naaqs/ has more information about the NAAQS. The predicted
Air Quality Index on these days will be in the unhealthy range. Fax or email notification
will be provided to local news media, employers, and other participating organizations
or interested individuals (usually by 4:00 p.m.).
There are now two basic types of Ozone Action Days:
- An Ozone Action Advisory will be declared when the AQI forecast
is code orange, indicating that prolonged
outdoor exertion is UNHEALTHY FOR SENSITIVE GROUPS (i.e., children and
persons with asthma or other breathing problems).
- An Ozone Action Alert will be declared when the AQI forecast
is code red, indicating that prolonged outdoor
exertion is UNHEALTHY FOR EVERYONE.
In addition, UNUSUALLY SENSITIVE PEOPLE should routinely
check the AQI as reported in newspapers and on the radio, television, and the Internet
and consider limiting prolonged outdoor exertion when the AQI is
A Web site dedicated to Ozone Action Days information has been set up by Metroplan.
ADEQ advises Metroplan on ozone-related issues and provides support.
Services Division of ADEQ calculates the local Air Quality Index (AQI), not to be
confused with the Ozone Forecast. It is a scale used to report actual levels
of ozone and the other four major atmospheric pollutants of concern (http://www.adeq.state.ar.us/techsvs/airmain.htm).
The higher the AQI value the greater the health concern.