High blood pressure increases the risk of strokes and heart problems
People living near noisy roads are at greater risk of developing high blood pressure, a Swedish study suggests.
A Lund University team found risk rose above an average daily exposure of 60 decibels, which accounts for about one in four people in western Europe.
They said it was likely noise caused stress - and maybe sleep disruption - leading to blood pressure problems.
But UK experts questioned the findings, saying other factors such as diet and smoking were more important.
Researchers analysed questionnaires completed by nearly 28,000 people as well as analysing neighbourhood traffic noise.
They found that at above 60 decibels the risk of high blood pressure rose by more than 25%.
Above 64 decibels the risk rose by more than 90% although the team cautioned that the low numbers in this group could have skewed the findings.
The report, published in the Environmental Health journal, said the findings were worrying as high blood pressure increased the chances of heart disease and stroke.
However, the link was not apparent for people above 60 years old. The researchers said this was either because they had become desensitised to the noise or already had high blood pressure.
Report author Theo Bodin said: "Road traffic noise is the most important source of community noise so we felt it was important to look at this.
"I think what we have found is probably linked to the noise triggering stress. Previous research has found this, although we need to look at this issue further before we make firm conclusions."
But Professor Alan Maryon-Davis, president of the UK's Faculty of Public Health, said: "It seems to me that they have found an association rather than a cause. Other factors, such as smoking, diet and deprivation, are likely to be playing more of a role.
"However, it is an area of research which merits further work."