RALEIGH — On hot, stuffy days like these the sun acts like an oven, cooking the chemicals emitted from cars and factories to create a nasty batch of unhealthy air. That's how ozone is created and high levels of ozone can have deadly consequences.

Winds from Wednesday afternoon thunderstorms helped to dissipate much of the smog that had built up in the Triangle, so no official smog alert was in effect. Tuesday, however, the Triangle surpassed federal health standards for smog for the first time in three years. If those conditions return dangerous levels could return.

Air Quality Expert Ellis Cowling says smog can pose serious health risks.

State health officials warn that, until the air starts moving again, elderly people, children, and people with lung or heart ailments should try to stay inside.

With each additional car on our highways come additional threats to our air quality. That's why scientists have been studying the air along Triangle highways.

Mark Smith of the North Carolina Division of Air Quality says crews have been out on Triangle roads measuring ozone levels.

An effort to find out what Triangle traffic are putting into the air.. it's making more ozone smog everyday.

Cowling says there will be more smog-related illness in this area as traffic continues to increase.

Smog can seriously damage the body. It could make breathing difficult, aggravate asthma, and inflame the lungs.

Ozone is a good thing in the upper atmosphere, where it blocks harmful rays from the sun. The problems arise when it drifts down into the lower atmosphere.