A further account goes as follows:
While trying to determine the risks involved, the authors first looked at the mixture of chemicals that make up second-hand smoke and its concentration in cars under different conditions such as volume, speed and ventilation. Second, they looked at how long a person would be in the car. Third, they observed how long a person would be exposed to the second-hand smoke. Fourth, the extent of difference between how second-hand smoke affects children compared to adults was added to the risk equation and finally, the authors looked at the health impact, which is hard to determine because of all the different chemicals and toxins a person is exposed to in their lifetime.I can't find much in the composition of smoke to get excited about: the diagram shows that smoke is about 90 per cent air and about 10 per cent a combination of other gases (further discussion here if you're interested). The account continues:
"Policy based on science and evidence has to exist amid uncertainty and this is managed by acknowledging the contingencies," write the authors. "Thus, i) because of the confirmed [confined?] cabin space, and ii) under the worst ventilation conditions, and iii) in terms of peak contamination, the evidence permits us to say that smoking in cars generates fine particulate concentrations that are, iv) very rarely experienced in the realm of air-quality studies, and that will thus constitute a significant health risk because, v) exposure to smoking in cars is still commonplace , and vi) children are particularly susceptible and vii) are open to further contamination if their parents are smokers."In the absence of any evidence on the smoke exposure levels in any individual car but taking a worst-case scenario, the authors attempt to pass this off as 'science', and use it to justify a policy that prohibits smoking in cars. They are correct (if this table is to be believed) that particulates of smoke are exceptionally fine (although the word 'concentrations' puzzles me as this depends entirely on the amount of smoking and air exchange). But calling this approach 'policy based on science and evidence' is taking the mick, when they're also saying that actual evidence isn't necessary.
I can't help feeling that the anti-smoking campaign did things the wrong way round if it wanted to convince us that it cares about children. First it went for smoking in the workplace and in pubs, in spite of warnings that people would smoke more at home. The rationale was to protect the workers. Only having achieved this did it start on protecting children in private spaces, with some local authorities prohibiting foster carers from smoking at home (claiming a stake in the shape of the children's health) and now cars are under discussion.
A policy based on children's health would have gone all out to make the claims about children first. This didn't happen because it would have meant an immediate intrusion on private space. The way it was done was the politically acceptable way: it has meant gazillions of car journeys have taken place in the meantime with children fully exposed to secondary smoke.
Not that I think it's done them any damage, or the ones exposed to smoke from their foster parents. If there is a genuine health issue many parents will respond to it by controlling smoke, but why disempower people with this 'no safe level of secondary smoke' nonsense?
If it comes to it, there's no safe level of anything.