Hawaii is the first state in the US to raise its smoking age to 21, a measure that was signed into law on Friday and will become effective January 1st. The law bans the sale of cigarettes and e-cigarettes to anyone under 21; it also bans their public possession and consumption until that age.

Bumping the age to 21 is expected to have a big impact

The law was passed amid growing concerns about the prevalence of e-cigarettes, the use of which is on the rise among teens. In its legislation, Hawaii notes that a poll of six of its high schools found that 25 percent of 9th and 10th grade students had used an electronic smoking device at least once and 18 percent used one regularly. "Raising the minimum age as part of our comprehensive tobacco control efforts will help reduce tobacco use among our youth and increase the likelihood that our keiki will grow up to be tobacco-free," Hawaii Governor David Ige says in a statement, using the Hawaiian word for children.

The state says that 34 percent of its current smokers picked up the habit between the ages of 18 and 20. That could be because that's when cigarette purchases become legal, but it suggests that bumping the age has the potential to significantly discourage smoking among a large group. Recent research from the Institute of Medicine has suggested just as much, with a recent report saying that nationwide smoking prevalence would fall by 12 percent with a national smoking age of 21, according to CNN.

While Hawaii has chosen to proactively ban e-cigarettes for those under 21, the US at large is generally undecided on what to do with them. Even Hawaii notes that e-cigarettes could be used as a potentially better alternative to traditional cigarettes, but it also fairly points out that "more research is needed" to determine "whether using electronic smoking devices carries more benefits than risks." The FDA is expected to issue new guidelines pertaining to that in the near future, which could place national restrictions on e-cigarette sales.

Hawaii says tobacco prevention efforts have already had huge health benefits

Hawaii says that it's been aggressive about its tobacco prevention efforts, leading to significant health improvements. The state says that between 2001 and 2012, heart disease deaths dropped 34 percent, stroke deaths dropped 43 percent, and lung cancer deaths dropped 21 percent. It claims to have the third-lowest adult smoking rate in the US, and it evidently wants to maintain that lead.

In doing so, Hawaii is adopting what appears to be somewhat stricter laws than most states. It bans the public possession and smoking of cigarettes by people under 21, whereas most states appear to just ban the sale of cigarettes. Violators can be subject to up to a $50 fine, which, if enforced, could disproportionately affect people with lower incomes. This doesn't appear to be a departure from Hawaii's existing policy, however, just a bump to the age limit.

Though Hawaii is the first state in the US to raise its smoking age to 21, some local governments have already made the leap. In 2013, New York City prohibited the sale of cigarettes to people under 21, raising the age from 18. That year, Hawaii County already made the change as well, raising the age from 18 to 21.