Traffic noise pushes up your blood pressure and risk of stroke

Traffic noise isn’t just annoying, it carries a number of health risks. Photo: Getty

John Elder

When living on a busy road, do we ever get used to tyres squealing and revving engines, the factory-like grunt and throb of trucks, sirens and angry horns honking?

We might learn to tune out the endless hum, but those violent mechanical outbursts tend to set our teeth on edge.

It’s not surprising, then, that a series of studies have found that long-term exposure to traffic noise, by virtue of where you live, pushes up your blood pressure.

This increases your risk of hypertension. This in turns raises your risk of stroke or heart attack.

What’s the evidence?

Research going back at least 20 years shows an association between residential road traffic noise and hypertension.

The latest study, by UK and Chinese researchers, has demonstrated a causal relationship.

For this, they accessed data of 240,000 people (aged 40 to 69 years) from the UK Biobank.

None of these participants had hypertension at the beginning of the study.

Next: The participants’ exposure to traffic noise was estimated based on their residential address – and using a modelling tool called the Common Noise Assessment Method.

The researchers then looked at who had developed hypertension over an eight-year period.

As expected, people living near road traffic noise were more likely to develop hypertension.

Further, and somewhat persuasive, this risk increased in tandem with the noise “dose”.

That is, the more exposure to traffic noise suffered by participants, the greater the effect on blood pressure and their risk of hypertension.

What about air pollution?

Previous studies were confused and weakened because “it was unclear whether noise or air pollution played a bigger role”.

The new research shows “that it is exposure to road traffic noise itself that can elevate hypertension risk”.

These associations held true “even when researchers adjusted for exposure to fine particles and nitrogen dioxide”.

However, people who had high exposure to both traffic noise and air pollution had the highest hypertension risk.

Dr Jing Huang, assistant professor in the Department of Occupational and Environmental Health Sciences in the School of Public Health at Peking University in Beijing, is the lead author of the study.

“We were a little surprised that the association between road traffic noise and hypertension was robust even after adjustment for air pollution,” he said.

What to do about it?

The researchers suggest that policy-makers could alleviate the adverse impacts of road traffic noise by:

  • Setting stricter noise guidelines and enforcement
  • Improving road conditions and urban design
  • Investing advanced technology on quieter vehicles.

Realistically, in the short-term at least, it may come down to individuals being aware that traffic noise, like a poor diet and lack of exercise, is bad for the heart.

To some extent, then, the impact of traffic noise might be mitigated by taking on a healthier lifestyle (which too few people tend to follow), investing in ear plugs … or moving to somewhere quieter.