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Childhood exposure to leaded petrol causes lower IQ, according to study

Wednesday 29 March 2017, By Autovolo

Childhood exposure to leaded petrol causes lower IQ, according to study

Childhood exposure to leaded petrol causes lower IQ, according to study

Exposure to leaded petrol during childhood leads to a lower IQ, new research has found.

Children with more than 10 micrograms of lead per 100 millilitres of blood at the age of 11 were found to be an average of 4.25 IQ points worse off compared with those with lower levels of lead in their blood.

Today, the Centre for Disease Control and Prevention says that “public health action” should be taken if blood lead levels are found to be above five micrograms.

Researchers at Duke University, North Carolina, also found that the higher the level of lead found in the children’s blood, the lower their IQ in adulthood. On average, for every five-microgram increase in the amount of lead found in a child’s blood level, they lost about 1.6 IQ points into adulthood.

The study looked at 1,000 people born in Dunedin, New Zealand, in 1972 and 1973, when the country had some of the highest petrol lead levels anywhere in the world. At 11, more than half of the children had blood samples taken to be analysed.

Participants were then regularly assessed for their ability to learn new information from childhood right through to adulthood.

Leaded petrol was introduced in the 1920s to improve the octane rating of fuel, which in turn improved engine performance. However, it started to be phased out by legislation during the ‘80s and ‘90s as health issues related to the addition of tetraethyl lead became public – though concerns about the additive had been raised as early as 1924.

Although leaded petrol is no longer available in most of the world, it is still available in parts of Asia and the Middle East.