Smog, or ground-level ozone, is harmful to breathe. It can appear as a yellow haze in the sky above polluted areas. Smog is formed in the atmosphere when certain chemicals combine with heat and sunlight. Power plants, fracking, cars and trucks, and diesel engines can all be sources of smog-forming chemicals. Smog can travel hundreds of miles from the pollution source, and it can be made worse by weather and geography.
What can smog do to you?
Smog is highly irritating to the lungs. It triggers asthma attacks, and increases the risk of lung infections; smog can interfere with normal lung development. Smog causes coughing, shortness of breath, and chest pain. Breathing elevated levels of smog is like getting a sunburn on the lungs.
What you can do.
Learn more about how smog harms our health by exploring our resources.
Join us in your state to work to keep the air cleaner and fight climate change.