non-stick saucepans
© AlamyRisk: The PFCs, or perfluorocarbons, that cause hormonal changes are found in household items such as non-stick saucepans and stain-resistant sprays

Gender-bending chemicals found in non-stick pans and food packaging are linked to early menopause, scientists say.

A major study has shown that women with the highest levels of the substances in their bodies go through 'the change' sooner than women with low levels.

PFCs, or perfluorocarbons, are found throughout the home.

They are breathed in via dust or vapour, or eaten in food, and have been linked to thyroid cancer, immune system problems and heart disease.

Many researchers believe they also act as hormone disrupters in the body.

They repel water and fat, and so have been used to make non-stick cookware, greaseproof food packaging and stain-resistant sprays for clothes and carpets.

The company 3M stopped using the chemicals in Scotchgard in 2002 due to health concerns. DuPont, manufacturer of Teflon, has agreed to phase them out by 2015.

The latest study looked at levels of PFCs in blood samples from 26,000 U.S. women.

The researchers, from West Virginia University, found levels were highest in women aged over 42 who had gone through the menopause.

Women in this age group with high levels of PFCs also had 'significantly lower' concentration of the female hormone oestrogen, the scientists report in the Journal of Clinical Endocrinology and Metabolism.

Dr Sarah Knox, who led the research, said: 'There is no doubt there is an association between exposure to PFCs and onset of menopause.'

But she stressed that the study had not shown that higher PFCs actually cause earlier menopause.

She added: 'Part of the explanation could be that women in these age groups have higher PFC levels because they are no longer losing PFCs with menstrual blood anymore, but it is still clinically disturbing because it would imply increased PFC exposure is the natural result of menopause.'

Dr Stuart Harrad from Birmingham University, an expert in indoor pollution, said most people's exposure to PFCs was well within the official safe levels in the UK.

But environmental campaigners urged women to reduce their exposure to man-made hormone disrupting chemicals in the home.

Gwynne Lyons, director of CHEM Trust, said: 'There is now widespread exposure to sex hormone disrupting chemicals that can have profound effects on our well-being.

'It is high time that the UK put health protection higher up the agenda and pushed for better EU regulation of hormone disrupters. Far better testing of chemicals prior to their widespread use is needed.'

A spokesman for the Food Standards Agency said it will look at the study but its own research into 'potential contaminants from non-stick coated and metal coated kitchenware products' found that levels were 'generally low and within safety limits'.