Traffic noise lowers life expectancy and increases risk of stroke

Do you lie awake at night frustrated by the constant noise of the city?  Living by a noisy road can make it harder to drift off and for many is a daily source of annoyance. New research from the London School of Hygiene & Tropical Medicine shows that traffic noise is not only annoying, it can decrease life expectancy and increase risk of stroke.

Around 8.6 million people living in London between 2003 and 2010 were monitored as part of the research published in the European Heart Journal. The study measured levels of road traffic noise between 7am and 11pm, and at night between 11pm and 7am, across a variety of postcodes in London, comparing the findings with death rates and the number of hospital admissions. Individual differences between participants including age, sex, ethnicity, smoking levels, air pollution and socio-economic levels were taken into account.

The World Health Organisation (WHO) states that daytime traffic noise louder than 55 dB can cause health problems. Guidelines recommended that the noise level for all communities should be less than 30 dB, however the WHO calculates that about 40 percent of people in EU counties are exposed to road traffic noise that exceeds levels of 55 dB. The research found that those surrounded by daytime traffic noise louder than 60 decibels (dB) were 4 percent more likely die to than those who only experienced noise levels of 55dB.

Traffic nose is also linked to heart disease, this is thought to be because stress brought on by the noise leads to raised blood pressure and sleep problems. The research found that adults living in areas with the noisiest daytime traffic were 5 percent more likely to be hospitalised for stroke than those living in quieter areas. For elderly people this risk increased to 9 percent.

“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.” – Lead scientist Dr Jaana Halonen, the London School of Hygiene & Tropical Medicine.