• Secondhand smoke
• Environment
• Public policy

Many take for granted the privilege to breathe clean air free of tobacco smoke. However, this privilege is not universal. The articles in this supplement highlight these points from different perspectives and populations and leave me wondering whether the glass is half full or half empty when it comes to world progress towards providing smoke-free environments.

Talias et al1 report that even in a country like Cyprus, where more than one in three are cigarette smokers, a comprehensive nationwide smoke-free law can be implemented without the proverbial economic sky falling. However, there are huge populations that are missing out on these smoke-free protections, which results in high Secondhand smoke (SHS) exposure levels and huge health care bills, not only in rural China2 but in other settings where the harms of SHS are not well recognised, such as in healthcare facilities that specialise treating patients with mental health conditions.3

Fortunately, things can be changed, even in populations that have traditionally been more accepting of tobacco use, such as the US military. Lando et al4 report on successful practices and communication strategies to adopt a comprehensive ban on smoking aboard US submarines. Al Mulla et al5 and Zhou et al remind us not to forget that non-cigarette products that are burned, like waterpipe, can quickly pollute the air just like cigarettes and at levels the US Environmental Protection Agency would classify as ‘hazardous’ if it were measured outdoors. This is particularly important because some smoke-free policies have loopholes that make enforcement of these policies problematic when it comes to waterpipe smoking.

As smoke-free air in public places becomes more widespread, an increasing share of SHS exposure is occurring in the home, where the adoption of smoke-free home policies can reduce particulate exposure by as much as 70%.6 However, as shown in the paper by Xie et al, solutions to this problem can be surprisingly easy. For example, healthcare providers simply asking pregnant non-smoking women if they are exposed to SHS provides valid data shown to be associated with small for gestational age births.7 Furthermore, such data can be used to screen those at risk and intervene to improve health outcomes of mothers and unborn children alike.

These studies provide a sampling of the progress made but also highlight populations where more work is to be done—whether that is in different geographic areas, with different occupational groups such as casino workers, or with different demographic sectors such as those with lower socioeconomic status or mental health comorbidities. Some may choose to focus on the gaps and view the smoke-free protections glass as half empty. However, social norms regarding smoking and SHS changing rapidly around the globe and entire countries are going smoke-free—something unthinkable not that long ago. I prefer to view the glass as half full as collectively we work to provide smoke-free environments to as many people as quickly as possible.