Infertility risk from shampoo

A common chemical, used in everything from shampoo to plastics, may be causing infertility in boys while they are still in the womb, it emerged yesterday.

Mothers-to-be, simply by washing their hair or using make-up, may unwittingly be increasing the risk of their sons suffering defective sex organs, low sperm counts and even cancer.

Substances called phthalates - found in shampoos, conditioners, skin lotions and make-up, as well as in the environment generally - are linked to a dramatically increased rate of abnormalities and infertility.

A two-year experiment which exposed rats to high levels of phthalates has shown that the chemical disrupts the male hormone testosterone at a crucial stage of foetal development, doubling the rate of defects and leading to low sperm counts.

Researchers believe that in some cases, cell changes caused by the chemicals may also increase the risk of testicular cancer later in life.

Phthalates are often not listed as an ingredient so people do not even know they are using them.

The number of infant boys suffering the two most common forms of genital abnormality has doubled in 50 years.

Up to 4 per cent of baby boys suffer an undescended testicle and about 0.7 per cent are born with an abnormality called hypospadias, which means they cannot pass urine normally.

Rates of testicular cancer, which is diagnosed in 2,000 British men every year, have risen by 84 per cent since the late 1970s. Pollution and 'gender bending' chemicals called oestrogens, found in pesticides, paints and plastics, have previously been suspected.

But the latest study by the Medical Research Council's human reproductive sciences unit in Edinburgh suggests phthalates are the culprit. The findings are to be presented at the British Fertility Society's annual conference at Aberdeen University this week.

Professor Richard Sharpe, senior MRC research scientist, said yesterday that the chemicals may affect hormone levels throughout life.

'What we have found has previously been overlooked by toxicologists testing phthalates.

'There are fundamental abnormalities with the development of testicular cells and the consequence is you get these genital disorders.'

Other studies had shown that women of reproductive age had higher levels of phthalates in their bodies. 'It could be because they are using more cosmetics and effectively spreading these chemicals over themselves,' he said.

The researchers exposed rats to phthalate levels estimated to be several hundred times higher than that which humans would encounter. But the average human exposure to phthalates is not exactly known.