Ozone in Our Environment
Ozone is a colorless gas with a noticeable smell.
Although ozone is a natural part of the atmosphere, it is also the main part of air pollution called smog. In the upper layer of the sky, ozone is helpful in protecting us from some of the effects of the sun. However, when it is in the lower layer close to Earth (outdoors and in our homes), it can be harmful if we breathe it in.