NICE girls may love a sailor, but they would do well to steer clear of kissing one who works in a submarine. A study from Japan showed that almost 80 per cent of submariners had signs of gum deterioration, and a third had severe tooth decay. The study, in New Scientist, says the state of dental hygiene among Japan's 1,200 submariners was 'extremely bad'.

The researchers suggest the dissolving tooth enamel might be caused by acidic gases given off by submarine batteries. The Japanese navy, however, has blamed poor dental hygiene.