According to the U.S. Environmental Protection Agency, roughly one out of every three people in the United States is at a higher risk of experiencing problems from ground-level ozone. Groups more vulnerable to ozone pollution include children, the elderly and people already suffering from respiratory illnesses.

• The respiratory system of a child is still developing and he or she breathes more often than the average adult. Plus, children spend significantly more time outdoors, especially in the summertime when ozone levels are the highest.
• Older populations are more likely to suffer from respiratory conditions, making them more susceptible to the effects of ozone pollution.
• Millions of Americans suffer from asthma, chronic bronchitis and other respiratory problems, many of which are triggered by ozone.

When ozone levels are elevated, it can irritate the respiratory system. Common symptoms include:

• Coughing, wheezing and difficulty breathing
• Chest pain or pain when taking a deep breath
• Aggravated asthma or other respiratory diseases
• Eye and throat irritation
• Headaches and/or fatigue.

Ground-level ozone can trigger and intensify asthma attacks.

Long-term ozone exposure has been linked to decreased lung function and diminished lung capacity, inflammation of the lung lining, increased respiratory discomfort and scarred lung tissue.