Men could end up with p-nises half-an-inch shorter than usual if their parents were exposed to high levels of a chemical used in non-stick frying pans.
Scientists have found the chemicals, called PFCs, can interfere with male hormones and lead to sexual organs being ‘significantly’ shorter and thinner.
And this effect is not only seen in the womb, the researchers said. PFCs could have toxic effects in teenagers, too.
The chemicals, also found in waterproof clothing and greaseproof packaging for food, get into the bloodstream and reduce testosterone levels.
Scientists found young men who grew up in an area polluted with PFCs have penises 12.5 per cent shorter and 6.3 per cent thinner than healthy men.
Researchers at the University of Padua in Italy made the discovery after measuring the penises of 383 men with an average age of 18.
Padua, near Venice, is in one of four areas in the world known to have high levels of PFC pollution, which used to be used in Teflon coating until it was phased out in 2013.
The chemicals, officially called perfluoroalkyl compounds, are also a health hazard in Dordrecht in the Netherlands, Shandong in China, and West Virginia in the US.
The Italian researchers found PFCs will bind to testosterone receptors and reduce levels of the male sex hormone used in the body.
As a result, men grow up with smaller penises, less healthy and mobile sperm and a shorter distance between their scrotum and anus – a sign of lower fertility.
‘As the first report on water contamination of PFCs goes back to 1977, the magnitude of the problem is alarming,’ said the researchers, led by Dr Andrea Di Nisio.
‘It affects an entire generation of young individuals, from 1978 onwards.’
PFCs come in hundreds of forms and are widely used to make everyday products more convenient and longer-lasting.
They are found in fast food packaging, paper plates, stain-resistant carpets, windshield washing fluid, fire-fighting foam and waterproof clothing.
PFCs are also in some glues, cosmetics, medicines, electronics, cleaning products, polishes and waxes, insecticides and paints.