I don't think we can conclude that, unless we assume up front that public policy is always made in a way that makes sense. It's entirely possible that the goal IS to improve public health, but also that politicians in Holland are as stupid as the ones we have here. Also, remember that when crafting legislation, competing interests are always weighed against each other and compromised; Holland has been a haven of sensible libertarian drug policy for many years now and to retreat from that even in a way that actually makes sense would be difficult and provoke opposition.

Norrin: if marijuana is less harmful to marijuana smokers than tobacco is to tobacco smokers, the reason is not that the smoke itself is less harmful but simply that far less of it is smoked. No pot smoker inhales 40 joints a day. Not even my ex-wife ever came near that. Use a little common sense; you cannot inhale particulates without risking lung damage. It doesn't matter whether it's tobacco smoke, pot smoke, smog, or wood smoke.

When we are talking about second-hand smoke rather than primary, how much of the stuff people smoke becomes irrelevant. If it's in the air and you're not smoking it yourself, you're going to be affected equally whether that's the only joint the smoker will smoke in that day, or one of 40 cigarettes. It will make a difference to the smoker himself, but not to you.