Enactment of smoke-free legislation in Europe and North America,
decreased preterm birth rates and childhood asthma exacerbations by 10%.

To assess the effects of such policies on pregnancy outcomes and risk
for childhood asthma, researchers conducted a meta-analysis of five
North American and six European studies involving >2.5 million
pregnancies and 247,168 asthma exacerbations.

Following the introduction of smoke-free policies, reductions of 10%
were promptly seen in rates of preterm birth and very-small-for-
gestational-age birth. In addition, rates of pediatric asthma
exacerbations fell by 10%.

Been JV et al. Effect of smoke-free legislation on perinatal and child
health: A systematic review and meta-analysis. Lancet 2014 May 3;
383:1549. (http://dx.doi.org/10.1016/S0140-6736(14)60082-9)PubMed
abstract
Kalkhoran S and Glantz SA.Smoke-free policies: Cleaning the air with
money to spare. Lancet 2014 May 3; 383:1526. (http://dx.doi.org/10.1016/S0140-6736(14)60224-5
)PubMed abstract