Are you living in the vicinity of a busy highway or an airport or even a hospital? Constant noise emanating from heavy city traffic, industrial machinery, aeroplanes and loud music may leave one at a higher risk of obesity and cardiovascular diseases.

In a four-year project, researchers from Karolinska University in Sweden found that the louder the traffic noise, the greater the increase in people's waist size.

"There was nearly a centimetre increase for every 10-decibel rise in the noise levels," the study authors noted.

The effects of noise pollution are even felt by babies in the womb.

"We are gathering more and more evidence that noise in the environment can have a direct effect on health,' said professor Adrian Davis, one of the authors of the study that appeared in the journal Lancet.

Noise pollution affects stress hormones including cortisol which raises likelihood of pounds packing on around the waist.

This visceral fat also pushes up heart attack risk.

In another study, researchers from Utrecht University in the Netherlands examined data from more than 68,000 births.

They found that for every six-decibel increase in traffic noise, there was a drop of 15g to 23g in birth weight.

Low birth weight is linked to a range of long-term health problems, including high blood pressure, diabetes and heart disease.

It also affects school children's academic performance, researchers said.