Our economy runs on diesel. It's burned in the road-going rigs that bring us everything from potatoes to potpourris. If it's on a store shelf, it likely arrived by oil-burning truck. Increasingly, diesel engines are also finding a home in our passenger cars, migrating from Europe, where they've long been popular.

And why not? With a higher energy density than gasoline, diesel fuel gives us more miles per gram of emitted CO2 and the engines that use it tend to give us motivational torque in a lower RPM range, where it's more useful. It appears, however, that there may be some substantial trade-offs when it comes to the effect of their exhaust particulate on our most precious resource: our children.

Women exposed to higher air pollution levels during their pregnancies were twice as likely to give birth to an autistic child.

A large, new study makes a solid link between air pollution and incidences of autism, with diesel particulate and mercury named as the most significant contributors. Research from the Harvard University's School of Public Health, drawing on 116,430 participants in the ongoing Nurses' Health Study, found that women exposed to higher air pollution levels during their pregnancies were twice as likely to give birth to an autistic child than those living in a cleaner environment. Previous studies have found similar connections.

The works don't, of course, suggest that this association means air pollution causes autism, only that there is a contributory link. Future research should involve taking blood samples from both mothers and babies to see exactly which chemicals are involved.

While pollution from both diesel exhaust and coal-powered electricity generation – a major contributor to air-borne mercury – has decreased over the 24-year period over which the study sample was taken, we hope this kind of work will provide impetus for further improvements.