Indicator Gauge Icon Legend
Legend Colors
Red is bad, green is good, blue is not statistically different/neutral.
Compared to Distribution
the value is in the best half of communities.
the value is in the 2nd worst quarter of communities.
the value is in the worst quarter of communities.
Compared to Target
meets target; 
does not meet target.
Compared to a Single Value
lower than the comparison value;
higher than the comparison value;
not statistically different from comparison value.
Trend
non-significant change over time; 
significant change over time; 
no change over time.
Compared to Prior Value
higher than the previous measurement period;
lower than the previous measurement period;
no statistically different change from previous measurement period.
Significantly better than the overall value
Significantly worse than the overall value
No significant difference with the overall value
No data on significance available
Annual Ozone Air Quality
Measurement Period: 2020-2022
This indicator is archived and is no longer being updated. Click to learn more
This indicator gives a grade to each county in the U.S. based on the annual number of high ozone days.
Why is this important?
While ozone is an important shield against ultraviolet rays in the Earth's upper atmosphere, it is a pollutant that can cause health problems at ground level. Ground-level ozone is formed when volatile organic compounds (VOCs) and nitrogen oxides (NOx) react in sunlight; both of these pollutants are found in emissions from vehicles, motorized equipment, factories, and some consumer products. Ozone primarily affects the respiratory tract, causing breathing difficulties, aggravating existing lung diseases, and inflaming lung tissue. Although everyone is susceptible to ozone's effects, children, people with lung disease, and older adults tend to be more sensitive to ozone.
4
Source:
American Lung Association
Measurement period: 2020-2022
Maintained by: Conduent Healthy Communities Institute
Last update: July 2024
Measurement period: 2020-2022
Maintained by: Conduent Healthy Communities Institute
Last update: July 2024
Compared to
Technical note: The American Lung Association (ALA) assigns grades A-F to counties (A=1; B=2; C=3; D=4; F=5), based on average annual number of days that ozone levels exceeded U.S. standards during the three year measurement period. The air quality data is collected by the EPA and summarized by the ALA.
Graph Selections
Data Source
- American Lung Association
Maintained By: Conduent Healthy Communities Institute (Methodology)
Filed under: Environmental Health / Air, Physical Determinants of Health