What are normal levels of ground level ozone?
Registered average natural background concen- trations of ground-level ozone are around 30–100 micrograms per cubic meter (µg/m3). Short-term (one-hour) mean ambient concentrations in urban areas may exceed 300–800 µg/m3 (WHO 1979).
What is a good ozone level?
0-50
Good (0-50) It’s a great day to be active outside. Moderate (51-100) Some people who may be un- usually sensitive to ozone. Unusually sensitive people: Consider reducing prolonged or heavy outdoor exertion. Watch for symptoms such as coughing or shortness of breath.
What are the standards for ozone?
Federal Standards EPA ozone standard is an 8-hour average of 0.08 parts per million by volume [ppm(v)] This standard is subdivided into primary standards that protect public health and secondary standards that protect public welfare (the numeric value of the standard is the same for primary and secondary standards).
What is the EPA air quality standard for ground level ozone?
70 parts per billion
EPA’s New Standard for Ground-level Ozone Specifically, EPA revised the primary (public health) and secondary (public welfare) 8-hour ozone standards to 70 parts per billion (ppb). The previous standard, the 2008 standard, was 75 ppb. The 70 ppb federal 8-hour ozone standard became effective on December 28, 2015.
What is an unhealthy ozone level?
Good (0-50) No health impacts are expected when air quality is in this range. Moderate (51-100) Unusually sensitive people should consider limiting prolonged outdoor exertion. Unhealthy for. Sensitive Groups. (101-150)
How can ground level ozone be controlled?
Cleaner burning gasoline reformulated to reduce VOC, NOx and other pollutants; Strict NOx emission limits for power plants and industrial combustion sources; Enhanced vehicle inspection programs in states; and.
What level of ozone is harmful?
These ozone molecules form the ozone layer and are commonly referred to as “good ozone.” At concentrations as high as 12,000 ppb (the EPA considers anything over 70 ppb to be unhealthy for human health and welfare) this ozone protects and shields people, trees, crops, property, and microorganisms from the harmful …
What is the 8-hour ozone standard?
The 2008 ozone standard is set at a level of 0.075 ppm averaged over an 8-hour period. This standard is met at an air quality monitor when the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentration is less than or equal to 0.075 ppm.
What is the current 8 hour standard for ozone?
0.070 parts per million
There is one federal primary standard for ozone – an 8-hour average standard of 0.070 parts per million (ppm); the secondary standard is the same as the primary.
Why is ground-level ozone bad?
Breathing ground-level ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ozone also can reduce lung function and inflame the lining of the lungs.
What are the current standards for ozone pollution?
Limiting ozone pollution in the air protects human health and the environment. In December 2020, EPA decided to retain the current ozone standards set in 2015: See information on decision. See the 2015 ozone NAAQS . See the 2008 ozone NAAQS .
What is the average ozone level in an 8 hour period?
The 2008 ozone standard is set at a level of 0.075 ppm averaged over an 8-hour period. This standard is met at an air quality monitor when the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentration is less than or equal to 0.075 ppm.
What does a review plan for ozone mean?
The review plan describes all the scientific assessments and other documents that help EPA decide whether or not the current air quality standards for ozone are still protecting human health and the environment from harmful exposure. Based on this, EPA either changes the standards or keeps them the same.
When did the EPA increase the ozone level?
Based on extensive scientific evidence about the effects of ozone on public health and welfare, on October 1, 2015, EPA strengthened the ground-level ozone standard to 0.070 ppm, averaged over an 8-hour period. This standard is met at an air quality monitor when the 3-year average…