So why were several members of ASH Scotland staff lurking by the highways and byways with a mysterious electronic device recently?
It was all part of our ongoing work to tackle the problem of children and other family members being exposed to second-hand smoke in their homes.
During the project, called REFRESH, we teamed up with Aberdeen and Edinburgh universities and used air-quality monitory equipment to work out the amount of fine particulate matter in the homes of smoking mothers.
The challenge was to convince smokers to light up outside, so we needed to demonstrate how much second-hand smoke lingers indoors to affect their children and loved-ones.
The initial tests showed average amounts of air pollution much higher than the daily limits recommended by the World Health Organisation, peaking at alarming levels.
We knew they were worse than pollution caused by industrial smog in Beijing and Singapore. But how did the figures compare to the busy streets of Glasgow or Edinburgh, we wondered?
Our efforts to find out the easy way were stymied. Although Friends of the Earth Scotland produce stats for the most polluted streets, they measure a larger type of particle than we looked for in homes.
So we had to take the DIY approach. Using our state-of-the-art monitors, our team staked out the busy thoroughfares of Lothian Road and George Street in Edinburgh and Royal Exchange Square in Glasgow. One took a monitor to his smoke-free home, even striking matches to tease the machine.
The results showed that the highest levels of air pollution in homes were more than 50 times greater than the maximum totals recorded in the busy city centre streets.
The REFRESH research found the mums were shocked by the level of invisible tobacco smoke in their homes, which remained high even if they were opening windows or smoking in a room away from their child. The measurements also showed just how long smoke hangs around in the air after a cigarette is put out.
There was a marked drop in the pollution levels in most of the homes in the study after the determined mums tackled the problem by only lighting up outside, containing their smoking in one room or cutting down on cigarettes. One even quit completely and others stopped smoking in the car.
Keep an eye out for more work under the REFRESH banner.