April 20, 2000
To Better Protect Public Health
With smog season just around the corner, Southland air quality officials will
switch to a new Air Quality Index next month to forecast and report smog levels
and to advise residents on how to adjust their daily activities to reduce
exposure to air pollution.
"The new Air Quality Index is based on the latest scientific health
findings and will do a better job of protecting public health, particularly for
sensitive individuals such as children, asthmatics and the elderly," said
William A. Burke, chairman of the South Coast Air Quality Management District’s
Governing Board.
The U.S. Environmental Protection Agency now requires all large metropolitan
areas in the country use the new Air
Quality Index (AQI). It replaces the old Pollutant Standards Index, first
established by EPA in 1976 to standardize air quality reporting across the
country.
With warmer temperatures and longer daylight hours, ozone levels will begin
to climb into unhealthy levels this spring. Last year was the cleanest on record
and the first time the region has not experienced a Stage 1 episode, when ozone
levels exceed 0.20 parts per million for a one-hour average. The region still
had 42 days exceeding the federal one-hour ozone standard.
While the weather causes considerable variation in smog levels from year to
year, the long-term trend of improving air quality is expected to continue this
year.
What’s New With the AQI
Like the old Pollutant Standards Index, the AQI uses a numerical scale from 0
to 500, with 0 representing pristine air and 500 extremely polluted air posing
an immediate and substantial danger to public health. (Southern California hasn’t
experienced levels above 400 since the early 1970s, and probably never will
again.)
The Pollutant Standards Index and the AQI both categorize air quality as
good, moderate, unhealthy, very unhealthy or hazardous, corresponding to
specific numerical ranges on the scales.
The AQI differs from the old Pollutant Standard Index in that it adds a new
category -- unhealthy for sensitive groups -- between moderate and unhealthy
designations.
EPA requires air quality agencies to use specified colors for each category
when displaying smog information graphically. (See following table)
New Air Quality Index
|
Color |
Air Quality |
Index Value |
Ozone level (8-hr. average, parts per million) |
Health Advice |
|
Green |
Good |
0-50 |
0-0.064 |
No health impacts are expected when air quality is in this range. |
|
Yellow |
Moderate |
51-100 |
0.065-0.084 |
Unusually sensitive people should consider limiting prolonged outdoor
exertion. |
|
Orange |
Unhealthy for Sensitive Groups |
101-150 |
0.085-0.104 |
Active children and adults, and people with respiratory disease, such
as asthma, should limit prolonged outdoor exertion |
|
Red |
Unhealthy |
151-200 |
0.105-0.124 |
Active children and adults, and people with respiratory disease, such
as asthma, should avoid prolonged outdoor exertion; everyone else,
especially children, should limit prolonged outdoor exertion |
|
Purple |
Very Unhealthy |
201-300 |
0.125-0.374 |
Active children and adults, and people with respiratory disease, such
as asthma, should avoid all outdoor exertion; everyone else, especially
children, should limit outdoor exertion |
Source: U.S. EPA
AQMD will forecast and report air quality to the public and media using the
new AQI by the following means:
- Media outlets can receive detailed air quality information electronically
via modem;
- Daily forecasts, current levels and the previous day’s levels are
displayed on the smog level pages of
AQMD’s web site;
- Southland schools receive daily forecasts from AQMD via fax; and
- Daily forecasts and up-to-the-minute air quality levels for each Southland
ZIP code are available by calling 800-CUT-SMOG® (800-288-7664).
"The new Air Quality Index should enhance the public’s awareness of
daily air quality and their understanding of how they can protect themselves
from smog’s harmful effects," Burke said.
AQMD is the air pollution control agency for Orange County and the urban
portions of Los Angeles, San Bernardino and Riverside counties.
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