Did anyone see this: www.guardian.co.uk/lifeandstyle/2010/jun/24/test-pregnant-women-smoking-nice ?
So they think they need a detector because otherwise we might lie about whether we smoke or not? I would be hopping mad if someone insisted on testing me to check if I smoked, for goodness sake, I still have a brain and I still have ability to tell the truth (and for what its worth I've never smoked).