People often live in areas where air pollution can affect their daily life or cause serious health problems. Like the weather, local air quality can change from day to day. The Clean Air Act requires EPA to set National Ambient Air Quality Standards for six common air pollutants. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants can harm your health and the environment, and cause property damage. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. Of the six pollutants, ground-level ozone and particle pollution are the most widespread health threats.
"Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles.
The size of particles is directly linked to their potential for causing health problems. Small particles less than 10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs and some may even get into your bloodstream.
Exposure to such particles can affect both your lungs and your heart. Particles of concern include "inhalable particles or PM10" (such as those found near roadways and dusty industries), which are 10 micrometers in diameter and smaller; and "fine particles or PM2.5" (such as those found in smoke and haze), which are 2.5 micrometers in diameter and smaller.
Given possible health effects and a concern for the health and safety of the local public, the Wyoming Department of Environment Quality (WDEQ) uses the EPA’s Air Quality Index guidance and advisory levels to inform sensitive groups and the general public of potential health risks associated with exposures to elevated levels of coarse particulate matter ( PM10).
| PM10Value* |
Descriptor
|
Group Notified
|
|---|---|---|
|
0-54 µg/m
3
|
Good | None |
|
55-154 µg/m
3
|
Moderate |
Unusually sensitive people should consider reducing prolonged
or heavy exertion. |
|
155-254 µg/m
3
|
Unhealthy for Sensitive Groups |
At or above 155 µg/m 3 for 24 hours, people with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion. |
| 255 µg/m 3 or greater | Unhealthy |
At or above 255 µg/m 3 for 24 hours, people with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion. Everyone else should reduce prolonged or heavy exertion. |
PM10 and PM2.5 should be assessed the same way for health effects. The charts will change since PM2.5 is finer and has a lower acceptable exposure limit and can affect a person’s health faster than PM10.
Source: EPA
| PM2.5Value* |
Descriptor
|
Group Notified
|
|---|---|---|
|
0-9.0 µg/m
3
|
Good | Air quality is satisfactory, and air pollution poses little or no risk. |
|
9.1-35.4 µg/m
3
|
Moderate |
Air quality is acceptable. However, there may be a risk for some people,
particularly those who are unusually sensitive to air pollution. |
|
35.5-55.4 µg/m
3
|
Unhealthy for Sensitive Groups |
Members of sensitive groups may experience health effects.
|
| 55.5-125.4 µg/m 3 | Unhealthy |
Some members of the general public may experience health effects;
|
| 125.5-225.4 µg/m 3 | Very Unhealthy |
Health alert: The risk of health effects is increased for everyone. |
| 225.5 µg/m 3 or greater | Hazardous |
Health warning of emergency conditions: everyone is more likely to be affected. |
Ozone is an air pollutant produced from human-caused emissions that reacts in sunlight. High concentrations of ozone can cause inflammation and irritation of the respiratory tract, particularly during heavy physical activity. Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue.
Given possible health effects and a concern for the health and safety of the local public, the Wyoming Department of Environmental Quality (WDEQ) uses the EPA’s Air Quality Index guidance and advisory levels to inform sensitive groups and the general public of potential health risks associated with exposures to elevated levels of ozone.
| Ozone |
Descriptor
|
Group Notified
|
|---|---|---|
|
0-54 ppb
|
Good | None |
|
55-70 ppb
|
Moderate | Unusually sensitive people should consider limiting prolonged outdoor exhertion |
|
71-85 ppb
|
Unhealthy for Sensitive Groups |
At or above 71 ppb for an 8-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should limit prolonged outdoor exertion. |
| 86-105 ppb | Unhealthy |
At or above 86 ppb for an 8-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should avoid prolonged outdoor exertion. Everyone else should limit prolonged outdoor exertion. |
| 106-200 ppb | Very Unhealthy |
At or above 106 ppb for an 8-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should avoid all outdoor exertion. Everyone else should limit outdoor exertion. |
Sulfur dioxide is a naturally occurring compound found in oil and natural gas as well as from geothermal features such as hot springs and volcanoes. High concentrations of sulfur dioxide can cause respiratory irritation and asthma like symptoms.
| Sulfur Dioxide |
Descriptor
|
Group Notified
|
|---|---|---|
|
0-35 ppb
|
Good | None |
|
36-75 ppb
|
Moderate | Unusually sensitive people should consider limiting prolonged outdoor exhertion |
|
76-185 ppb
|
Unhealthy for Sensitive Groups |
At or above 76 ppb for a 1-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should limit prolonged outdoor exertion. |
| 186 ppb or greater | Unhealthy for General Public |
At or above 186 ppb for a 1-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should avoid prolonged outdoor exertion. Everyone else should limit prolonged outdoor exertion. |
Carbon monoxide is a naturally occurring and man-made compound. It is produced from incomplete burning of a substance such as fossil fuels or wood. People exposed to high concentrations or are sensitive to carbon monoxide may experience headache, nausea, dizziness, breathing difficulties, or chest pain.
Source: CDC
| Carbon Monoxide |
Descriptor
|
Group Notified
|
|---|---|---|
|
0-4.4 ppm
|
Good | None |
|
4.5-9.4 ppm
|
Moderate | Unusually sensitive people should consider limiting prolonged outdoor exhertion |
|
9.5-12.4 ppm
|
Unhealthy for Sensitive Groups |
At or above 9.4 ppm for a 8-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should limit prolonged outdoor exertion. |
| 12.5 ppm or greater | Unhealthy for General Public |
At or above 12.5 ppm for a 8-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should avoid prolonged outdoor exertion. Everyone else should limit prolonged outdoor exertion. |
Nitrogen dioxide is formed when burning nitrogen containing compounds that are found in fossil fuels. In large cities, nitrogen dioxide is one of the components for smog creating a reddish-brown gas. People exposed to high concentrations or are sensitive to nitrogen dioxide may experience irritation to eyes, nose or throat; coughing; breathing difficulty; chest pain; pulmonary edema; or asthma like symptoms.
Source: CDC
| Nitrogen Dioxide |
Descriptor
|
Group Notified
|
|---|---|---|
|
0-53 ppb
|
Good | None |
|
54-100 ppb
|
Moderate | Unusually sensitive people should consider limiting prolonged outdoor exhertion |
|
101-360 ppb
|
Unhealthy for Sensitive Groups |
At or above 101 ppb for a 1-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should limit prolonged outdoor exertion. |
| 361 ppb or greater | Unhealthy for General Public |
At or above 361 ppb for a 1-hour average, children, older adults, people with respiratory problems, and people who are active outdoors should avoid prolonged outdoor exertion. Everyone else should limit prolonged outdoor exertion. |
