Health and Environmental Effects
Ozone Effects on Human Health
Ozone in the air we breathe can harm our health -- typically on hot, sunny days when ozone can reach unhealthy levels. Ozone can irritate respiratory systems and increase the susceptibility of the lungs to infections, allergens, and other air pollutants. Medical studies have shown that health problems caused by ozone may continue long after exposure has ended.
When ozone levels are very high, everyone should be concerned about ozone exposure. In general, as concentrations of ground-level ozone increase, both the number of people affected and the seriousness of the health effects increase. Several groups of people are particularly sensitive to ozone, especially when they are active outdoors, including:
- People with lung diseases (asthma, chronic bronchitis, emphysema, etc)
- Children, especially when playing outdoors
- Older adults, in particular those with pre-existing lung diseases
- Active people of all ages exercising or working outdoors
- Some healthy people with increased sensitivity, even without the risk factors listed above
(Source: National Park Service)
Ground-level ozone can cause the following health effects even at low concentrations:
- Aggravate asthma or other respiratory illnesses such as emphysema and chronic bronchitis
- Irritate respiratory systems causing coughing and throat irritation
- Inflame and damage cells that line the lungs
- Reduce lung capacity, making it difficult to take deep breaths
- Increase hospitalizations by aggravating respiratory illnesses
- Continue to damage the lungs even when the symptoms have disappeared
These health issues may lead to increased school absences, medication use, visits to doctors and emergency rooms, and hospital admissions.
(Source: EPA)
Ozone Effects on the Environment
Ground-level ozone can negatively affect individual plants, as well as entire ecosystems in the following ways:
- Loss of species diversity (less variety of plants, animals, insects, and fish)
- Changes to the specific assortment of plants present in a forest
- Changes to habitat quality
- Changes to water and nutrient cycles
(Source: EPA)
Photo of healthy (top) and ozone-injured (bottom) tulip tree (yellow poplar) foliage.
(Source: National Park Service)
Sensitive plants exhibit some of the following outcomes to exposure of ground-level ozone:
- Reduced photosynthesis
- Slow growth
- Increased risk from diseases, insect, other pollutants, and harm from severe weather
(Source: EPA)
Updated: July 31, 2018