 Ozone is a gas composed of three atoms of oxygen. Ozone can be good or bad depending on location. Good ozone occurs naturally in the stratosphere, forming a protective layer against dangerous ultraviolet rays. Ozone at ground level is a toxic air pollutant that can worsen respiratory issues, damage lungs, and harm wildlife. Ground level ozone is created when certain air pollutants are exposed to sunlight. Dangerous ozone levels are found mostly in urban areas in the summer, but wind can carry ozone long distances. Look for ways you can help reduce ground level ozone and keep the air cleaner.