Diesel fumes ‘raise autism risk in babies’

PREGNANT women exposed to traffic fumes are more likely to have children with autism, scientists have warned.

They said unborn babies exposed to the highest rates of nitric oxide from diesel emissions had an increased risk of developing the condition.

researchers studied a population of 132,256 children born from 2004 to 2009 in Vancouver, Canada. By the age of five, 1 per cent had been diagnosed with autism spectrum disorders (ASD).

Those whose mothers were exposed to higher levels of nitric oxide in air pollution when pregnant were at the highest risk.

study leader Lief Pagalan, of simon Fraser university, British Columbia, said the increase was small but significant.

‘While the odds ratio was small, a small increase in relative risk for high prevalence exposures can result in a large burden of disease,’ he wrote in the journal JAMA Paediatrics.

The study found the odds of developing autism for children whose mothers breathed in higher levels of nitric oxide was 1.07 per cent compared to 1 per cent for the group overall.

The academics said: ‘These findings suggest that reducing exposure to nitric oxide for pregnant women may be associated with a reduction in ASD incidence.’

However, Dr rosa Hoekstra, of King’s College London, said: ‘Because this study was conducted in a very large study group, even a very slight increase in risk could be detected. However, the increase was only very slight.

‘We can’t tell from this study whether it is the air pollutant or something else that causes any increase in autism risk. Previous studies examining an association reported conflicting results.’