Your fry-up's lethal leftovers

The cooking of food is one of the most significant sources of indoor air pollution, and frying foods, as for stir-frys and fry-ups, is one of the biggest culprits.

John Cherrie at the Institute of Occupational Medicine in Edinburgh has found that gas and electric cookers emit particles between 10nm and 100nm in diameter. With colleagues, he measured concentrations of about 200,000 particles per cubic cm.

Frying fatty food could raise the level to 1.6 million particles per cubic cm. Electric cookers were less polluting than gas cookers, which also produce nitrogen dioxide in high levels - up to 900 parts per billion.

The scientists are analysing data to find the biological toxicity associated with this pollution. The implication is that a well-ventilated kitchen would minimise any potential risk.