New Study Finds Road Traffic Noise May Impact Life Expectancy

Road traffic noise and early deaths
A van drives clockwise along the M25, as anti-clockwise traffic is at a standstill after heavy rain and road works caused a 20 mile jam on London's orbital motorway, November 14, 2014. Peter Nicholls/ REUTERS

Living close to noisy road traffic over a long period of time could reduce life expectancy, according to new research by the London School of Hygiene & Tropical Medicine.

The findings are from the largest study of its kind to date to link road noise to death and were published in the June issue of the European Heart Journal. They suggest a link between long-term exposure to road traffic noise and deaths, as well as a greater risk of stroke, particularly in the elderly.

Researchers analyzed data from millions of Londoners between 2003 and 2010, and assessed levels of road traffic noise in areas around the capital during the day and night. They then compared this data to deaths and hospital admissions in each area for adults and the elderly.

They found that deaths were 4% more common among adults and the elderly in areas with daytime road traffic noise of more than 60 decibels (dB) compared to areas with less than 55dB.

The deaths are most likely connected to cardiovascular disease, which could be due to increased blood pressure, sleep problems and stress as a result from high traffic noise levels.

Adults living in areas with the noisiest daytime traffic (more than 60dB) were 5% more likely to be admitted to hospital for stroke compared to those who lived in quieter areas (less than 55dB), which went up to 9% in the elderly. Night time noise (55-60 dB) from road traffic was also associated with a 5% increased stroke risk, but only in the elderly.

"Road traffic noise has previously been associated with sleep problems and increased blood pressure, but our study is the first in the UK to show a link with deaths and strokes, said lead author Dr Jaana Halonen from the London School of Hygiene & Tropical Medicine. "Our findings contribute to the body of evidence suggesting reductions in traffic noise could be beneficial to our health."

In London more than 1.6 million people are exposed to daytime road traffic noise levels above 55dB, which the World Health Organization defines as a level of community noise that causes health problems.

Yet co-author Dr Anna Hansell from the MRC-PHE Centre for Environment & Health at Imperial College London, added that the risks of noise to an individual are likely to be small in comparison with known risk factors for circulatory diseases like diet, smoking, lack of exercise, and medical conditions such as raised blood pressure and diabetes.

"However, our study does raise important questions about the potential health effects of noise in our cities that need further investigation", Hansell concludes.