Growing evidence for new benefit of clean indoor air laws: reduced adolescent smoking.

A s the evidence for the risks of harm from exposure to secondhand smoke has grown, so laws and policies to protect workers, children, and other community members from exposure have escalated. Clean indoor air laws are gradually becoming more common, even in traditionally hard to change venues such as restaurants and bars, with countries such as Ireland, Norway, New Zealand, Italy, most Australian states, and a growing number of US states and cities having passed laws eliminating indoor smoking in such venues. While this is good news for protecting the health of nonsmokers, researchers have begun to document another less obvious, but equally welcome, consequence of these changing circumstances in where people can freely smoke. Until now, only cross sectional research studies had noted a relationship between clean indoor air laws and reduced adolescent smoking. In this issue, Siegel and colleagues report findings from the first longitudinal study to have linked variation in the existence and strength of community level smokefree policies to youth smoking uptake. They found that youth living in towns with smoke-free restaurant laws that completely banned smoking had lower rates of progression to smoking than those youth living in towns with weaker or no laws. Effects were stronger when smoke-free laws had been in place for longer, and were not explained by a large number of possible individual or community level covariates.