How traffic noise near home hastens early death

*Sound linked to higher stroke, heart disease prevalence, lower life expectancy 

WE are all gradually getting used to it. But it is killing us softly. Yes! New research suggests that traffic noise can shorten one’s life. Having to endure rumbling lorries, honking horns and screeching tyres has been linked to shorter life expectancy and a higher risk of stroke.

People surrounded by daytime traffic noise louder than 60db were four per cent more likely to die than those where noise levels were 55db – roughly the level of a loud conversation.

The extra deaths mostly involved heart or artery disease – which could in turn be linked to raised blood pressure, sleep problems and stress brought on by noise, the scientists claim.

A total of 8.6 million living in London between 2003 and 2010 provided data for the study, reported in the European Heart Journal. Lead scientist, Dr. Jaana Halonen, from the London School of Hygiene & Tropical Medicine, said: ‘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.

“This is the largest study of its kind to date, looking at everyone living inside the M25 over a seven-year period. Our findings contribute to the body of evidence suggesting reductions in traffic noise could be beneficial to our health.”

The World Health Organisation defines 55dB as a noise level that can cause health problems in a community. In London, more than 1.6 million people are exposed to daytime road traffic noise louder than this threshold.

The study also found that adults living in areas with the noisiest daytime traffic were five more likely to be admitted to hospital for stroke than those from quieter neighbourhoods. For the elderly, this increase in risk rose to nine per cent. Between 2003 and 2010, a total of 442,560 adults from the study population died from all causes, of whom 291,139 were elderly.

The scientists looked levels of road traffic noise between 7am and 11pm, and at night between 11pm and 7am, across a range of different postcodes and correlated their findings with death and hospital admission rates.

A number of factors – including individuals’ age and sex as well as ethnicity, smoking levels, air pollution and socio-economic deprivation – were taken into account.

People surrounded by daytime traffic noise louder than 60db were four per cent more likely to die than those where noise levels were 55db – roughly the level of a loud conversation. The extra deaths mostly involved heart or artery disease – which could in turn be linked to raised blood pressure, sleep problems and stress brought on by noise, the scientists claim.

Commenting on the findings, Professor Francesco Cappuccio, chair of Cardiovascular Medicine and Epidemiology at the University of Warwick, said: “The results do not imply a direct cause-effect relationship. However, they are consistent with other evidence to suggest a possible causal link.

“For instance, it has been well established that nocturnal traffic noise disrupts sleep quantity and quality.

If sustained over time, these disturbances, like sleep deprivation, have been associated with a 12 per cent increased risk of all-cause mortality, mainly due to a 15 per cent increase in stroke events and high blood pressure. “Public health policies must pay more attention to this emerging evidence.”

Dr. Tim Chico, consultant cardiologist at the University of Sheffield, said: “There may be other factors that link high noise areas with cardiovascular disease, and it is difficult to take all of these into account.

“Nevertheless, given what we know about traffic emissions increasing heart disease, we should remember that travelling by foot or bike is definitely healthier – both for you and for the people around you.”