Decade-long encouragement by successive UK governments to get motorists to switch to diesel engine vehicles looks to be completely wrong-headed, according to research from the Air Quality Expert Group, part of the Department of Environment, Food and Rural Affairs.

Not only do diesel emissions containing chemicals like Nitrogen dioxide cause respiratory ailments, scientists think they can increase cases of autism and schizophrenia in children, the Daily Mail reported.

The studies showed that frequent and sustained exposure to diesel fumes alters the way the brain develops, and emissions are potent enough to cause children to develop autism and schizophrenia.

Dr Ian Mudway of Kings College, who co-authored the Defra-commissioned report, said "strong evidence" linked diesel pollutants to the development of cognitive function in children.

Earlier research by University of Southern California concluded that children exposed high levels fumes were three times as likely to have autism, compared to those living in pollution-free habitats.

The study linked exposure to traffic pollution during pregnancy and in children's early years, to higher rates of autism and other brain disorders.

Last week a cloud of smog covered London, and the emergency control centres got calls from people in different parts of the city complaining of breathing difficulties.

diesel autism
The study linked exposure to traffic pollution during pregnancy and in children\'s early years, to higher rates of autism Getty

Petrol cars were not free of dangerous pollutants either. Lead in petrol is also associated with brain damage in children, and was banned in 1999. Since then government advocated promoting diesel cars instead.

The study on association between diesel pollutants and autism was largely based on inputs from the US, but Mudway plans to carry out extensive research in London where the level of diesel pollutants in higher than in California.

The findings have prompted scientists to strongly recommend a change in policy. At this stage a switch back to petrol would possibly be the best fire fighting measure, they said. However, at present a third of Britain's private vehicles are run on diesel.