The majority of North Carolina's school districts already banned tobacco use on school grounds by spring of this year.

State law requires every school to become tobacco-free by the end of the week. The policy means tobacco use -- by visitors, teachers, and students -- is banned on school grounds. And tobacco use is banned at any school-sponsored event.

"Our research has shown that students in tobacco-free school districts have 40 percent lower smoking rates than students in non-tobacco-free school districts," said Rebecca Williams, who works with the Center for Health Promotion and Disease Prevention at UNC-Chapel Hill.

She believes the policy will help reduce youth smoking rates in North Carolina.

If you're visiting a public school in our state, make sure you leave the cigarettes and chewing tobacco at home.

The majority of North Carolina's school districts already banned tobacco use on school grounds by spring of this year. But the N.C. Health and Wellness Trust Fund claims five districts still needed to make progress, including Johnston County.

"Currently Johnston County schools has a 'no smoking' policy for students, and so this takes our policy to another level," explained Crystal Roberts, a spokeswoman for the school system.

Roberts believes the "tobacco-free school" policy helps schools establish a new norm.

"Students, young people, youth tend to do what you do," she said. "So if they see that we are taking measures to lead a healthy lifestyle, then, more than likely, they will do the same."

Williams agreed, adding that the policy "creates a social norm that smoking is not the thing to do."

People who violate the policy face a range of consequences. Students can be offered classes to help them quit, or even face suspension as a last resort. School visitors can be asked to leave school grounds, or be referred to local law enforcement officers.