The United States Environmental Protection Agency proposed new stricter health standards for Ozone. Ozone is linked to a number of serious health problems, ranging from aggravation of asthma to increased risk of premature death in people with heart or lung disease. Ozone can also harm healthy people who work and play outdoors. Children are at the greatest risk from ozone, because their lungs are still developing, they are more likely to be active outdoors, and they are more likely than adults to have asthma. Adults with asthma or other lung diseases, and older adults are also sensitive to ozone.