How chemical in plastic weakens children’s teeth

EXPOSURE to a common chemical found in plastic food containers can weaken children’s teeth irreversibly, according to a study.

Bisphenol A (BPA), which is found in items such as refillable drinks bottles, can stop youngsters’ dental enamel developing properly, scientists say.

Researchers warned that the chemical should be avoided by children until they are five years old.

The same issue was also caused by a fungicide called vinclozolin, which is commonly used in vineyards, golf courses and orchards.

The substances – known as endocrine disrupters – affect the hormones needed for stimulating growth of enamel.

Study lead author Dr Katia Jedeon said: ‘Tooth enamel starts at the third trimester of pregnancy and ends at the age of five, so minimising exposure to endocrine disruptors at this stage in life as a precautionary measure would be one way of reducing the risk of enamel weakening.’

In the study, which is to be presented at the European Congress of Endocrinology, scientists gave rats daily doses of BPA alone or with vinclozolin – equivalent to the average exposure humans have on a daily basis – from birth until they were 30 days old. The researchers, from the French National Institute of Health and Medical Research, then collected cells from the rats’ teeth surface and found BPA and vinclozolin affected the two genes that control the mineralisation of tooth enamel.

BPA was discovered in 1891 by a Russian chemist, and has been used to harden clear plastics since 1957. It resembles the female oes- trogen hormone and has sometimes been referred to as a ‘genderbending’ chemical.

Plastics made with BPA are especially useful for lining the inside of tins for better sealing.

The chemical can enter the body through food that has been kept in packaging containing BPA, handling packaging or even through breathing in household dust.

It is not listed on labels so there is no way to keep track of levels of daily exposure.

In both the EU and the US, BPA has been banned from use in babies’ bottles because the chemical can be released if the bottles are heated to high temperatures. Babies do not have the capacity to remove it from their bodies.

However, the Food Standards Agency and the European Food Safety Organisation have said the chemical is not a safety concern. Campbell’s Soup has said that it is to stop using BPA in its cans from next year.

Vinclozolin is not acutely toxic, and it has been classified by the World Health Organisation as ‘unlikely to present acute hazard in normal use’.

It is used as a pesticide on oilseed rape, apples, peas and beans.

Friends of the Earth said the chemical has been found in imported celery, strawberries, kiwi fruits, grapes, carrots, green beans, raspberries and lettuce.

Last month Danish scientists said that low doses of BPA could harm sperm count and even contribute to obesity.

Their research on rats also found that the chemical affected breast development of offspring.

Professor Ulla Hass, from Denmark’s National Food Institute, said: ‘The health risks of bisphenol A are especially of concern for highly exposed consumers. This applies in particular to pregnant or nursing women and children, who are especially sensitive to the adverse effects of bisphenol A that may occur at low exposure levels.’

The study found that female rats’ behaviour changed so that they resembled males, in a way that ‘could indicate masculinisation of the females’ brains’.