Passive smoking

As a non-smoker, I have benefited from the UK's smoking ban. My clothes no longer stink after a night out, and nice meals are no longer spoiled by someone else's après-dinner cigarettes.

As a libertarian, however, I bitterly resent this government interference. If non-smokers felt strongly enough about second hand smoke, the free market would have met their desire for smoke-free (or properly ventilated) pubs and restaurants.

Not content with the ban on smoking in public spaces, the puritans are putting increasing pressure on people to abstain from smoking at home. As usual, a favourite angle of attack is the appeal to think of the children.

And as usual, the BBC is happy to oblige: "Passive smoking increases stillbirth risk, says study".

University of Nottingham researchers found that pregnant women exposed to smoke at work or home increased their risk of stillbirth by 23% and of having a baby with defects by 13%.

Nowhere in the article does it say what the baseline risk of stillbirth or birth defects is, or how the supposed risk from passive smoking compares with other risk factors, such as age, diet, and genetics.

A quick search turned up a BBC article from 2009 claiming that

Every year in the UK nearly 4,000 babies are stillborn

Again, the BBC refused to put this figure in context, but according to the ONS

There were 706,248 live births in 2009.

This means that, on average, 0.5663% of babies are stillborn (1 in 176) versus 0.6966% when the mother is exposed to smoke (1 in 143).

But if you read far enough down the original article, you find this:

Dr Jo Leonardi-Bee, lead researcher of the study and associate professor in medical statistics at the University of Nottingham, said they still did not know when the effects of the second-hand smoke begin.

"What we still don't know is whether it is the effect of sidestream smoke that the woman inhales that increases these particular risks or whether it is the direct effect of mainstream smoke that the father inhales during smoking that affects sperm development, or possibly both.

"More research is needed into this issue although we already know that smoking does have an impact on sperm development, so it is very important that men quit smoking before trying for a baby."

Far from being unsure about "when the effects of the second-hand smoke begin" the researchers actually have no idea whether passive smoking is in fact the problem — it could be the effect on sperm of primary smoking.

As far as I'm concerned, it's not yet clear that second-hand smoking will make you ill, but the BBC certainly makes me sick!