Air pollution leads to smaller babies, it has been found.
In the University of Western Australia study, researchers monitored traffic emission levels in a region with relatively low industrial activity, and compared it with the birth records of over 1,000 mothers over a period of six years between 2000 and 2006.
The research was led by Assistant Professor Gavin Pereira, and the UWA's affiliate, The Telethon Institute for Child Health Research, was also involved in the project.
The results published today in the Australian and New Zealand Journal of Public Health show that a neonate who would have otherwise attained an optimal birth weight of 3.5 kg would be expected to be born 58 g lighter. The results reflect about half of the effect observed for maternal smoking during pregnancy among this group.
Assistant Professor Pereira, whose research interests are in traffic, air pollution and childhood health, said the results were surprising because these effects were observed when air quality guidelines met national standards.
"International studies have found some associations but this is the first time we have seen a specific link between normal suburban traffic pollution and its effect on the fetal growth."
He said while the results should not cause alarm, the warning signs should not be ignored.
"There is a message to be taken from this research. We all have a responsibility to keep emission levels down - drive less, catch public transport, cycle more, walk more. The health benefits of active travel add to the health benefits of not contributing to traffic emissions," he said.
Assistant Professor Pereira's work is now looking into the influence of the built environment on physical activity and chronic disease across the life course. Informing urban design might be one strategy to lessen the burden of some of the major diseases like obesity, diabetes, cardiovascular disease and asthma.