Over at his BadScience blog, Ben Goldacre has had a close look at yet another dubious use of basic statistics. It's to do with the provision of carbon monoxide monitors in council housing in the UK. Carbon monoxide (CO) is a nasty thing - you can't smell it, & it can kill you very dead quite quickly: CO binds very strongly to the haemoglobin in your bloodstream - more strongly than oxygen, & each haemoglobin molecule that's clutchng a CO molecule is thus unavailable to carry oxygen to your cells. Anyway, a factoid released to the UK press (as part of a sales pitch, perhaps) claimed that an alarmingly high number of British council-owned flats weren't fitted with CO detectors. However, this claim was based on some rather creative mathematics, which Ben proceeds to pull to pieces.