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Data
In the past,
the answers to environmental questions were unavailable or often slow in
coming. And when you did get them, chances are the answers were outdated
and difficult to understand. To address this problem, in 1996
President Clinton directed the U.S. Environmental Protection Agency (EPA)
to create a new program, Environmental Monitoring for Public Access and
Community Tracking (EMPACT), to bring to people up-to-date environmental
information they could understand and use every day.
Air Info
Now and Pima County Department of Environmental Quality (PDEQ) are
currently working on bringing this real-time air quality information to
the public. This information will help communities and individuals make
informed, day-to-day decisions about their lives.
Information
is currently offered through these areas:
Please note: Many of these reports display values for 1-hour PM10 and PM2.5 (particulate matter 10 and 2.5 microns or less in diameter) concentrations. These data values are provided for informational purposes only. The EPA Health Standard for PM10 and PM2.5 is a 24-hour standard, based on the average of 24 hourly readings from midnight to midnight. The EPA has not yet developed a 1-hour standard for PM10 or PM2.5.
National
Ambient Air Quality Standards (NAAQS)1
The Clean Air Act, which was last amended in 1990, requires EPA to set
National Ambient Air Quality Standards for pollutants considered
harmful to public health and the environment. The Clean Air Act
established two types of national air quality standards. Primary
standards set limits to protect public health, including the
health of "sensitive" populations such as asthmatics, children, and the
elderly. Secondary standards set limits to protect public
welfare, including protection against decreased visibility, damage to
animals, crops, vegetation, and buildings.
The EPA Office of Air Quality Planning and Standards (OAQPS) has set
National Ambient Air Quality Standards for six principal pollutants,
which are called "criteria" pollutants. They are listed below.
Units of measure for the standards are
parts per million (ppm) by volume,
milligrams per cubic meter of air (mg/m3), and
micrograms per cubic meter of air (µg/m3).
Pima County is currently in attainment (compliance) with the National
Ambient Air Quality Standards for all of the criteria pollutants.
National Ambient Air Quality Standards
| POLLUTANT
|
STANDARD
VALUE
* |
STANDARD
TYPE
|
Carbon Monoxide (CO) |
| 8-hour Average
|
9 ppm |
(10 mg/m3)
|
Primary |
| 1-hour Average
|
35 ppm |
(40 mg/m3)
|
Primary |
Nitrogen Dioxide (NO2)
|
| Annual Arithmetic Mean |
0.053 ppm
|
(100 µg/m3) |
Primary & Secondary
|
Ozone (O3) |
| 8-hour Average |
0.075 ppm |
|
Primary & Secondary |
Lead (Pb)
|
| Quarterly Average |
1.5 µg/m3
|
|
Primary & Secondary
|
Particulate (PM 10)
Particles with diameters of 10 micrometers or less |
| Annual Arithmetic Mean
|
50 µg/m3 |
|
Primary & Secondary |
| 24-hour Average
|
150 µg/m3 |
|
Primary & Secondary |
Particulate (PM 2.5)
Particles with diameters of 2.5 micrometers or less
|
| Annual Arithmetic Mean |
15 µg/m3 |
|
Primary & Secondary |
| 24-hour Average |
65 µg/m3 |
|
Primary & Secondary |
Sulfur Dioxide (SO2) |
| Annual Arithmetic Mean
|
0.03 ppm |
(80 µg/m3)
|
Primary |
| 24-hour Average
|
0.14 ppm |
(365 µg/m3)
|
Primary |
| 3-hour Average
|
0.50 ppm |
(1300 µg/m3)
|
Secondary |
|
|
