London - Children exposed to air pollution when in the womb are more likely to have high blood pressure, researchers have found.
They believe that tiny particles from car exhausts and factories can cross the placenta and cause long-term harm.
Their study – the first of its kind – looked at 1 293 mothers and their children aged three to nine. Youngsters exposed to the highest level of pollution in the last three months of pregnancy were 61 percent more likely to have high blood pressure.
The researchers looked at "fine particulate matter", which is produced by cars and the burning of coal. Dr Noel Mueller, who led the study at Johns Hopkins University, Baltimore, said the results – published in the journal Hypertension – showed the need for clean air regulations. But he said it was too early to say for sure that pollution caused the high blood pressure.
Oliver Hayes of Friends of the Earth said the study was the latest to highlight the risks of air pollution to unborn babies.