Traffic noise and hypertension

Exposure to traffic noise might raise the risk of developing high blood pressure.

Studies in the past have found that people living near airports or working in noisy atmosphere have an increased risk of high blood pressure and heart attack. To explore the associations between road traffic and hypertension, researchers from Sweden surveyed 24,238 adults (aged between 18 and 80 years) about their health and lifestyle. They also collected traffic data to estimate participants' average exposure to road noise at home.

Of adults aged 40 to 59 years, around 28 per cent of those with the highest traffic- noise exposure said they had high blood pressure, versus 17 per cent of those living near the quietest roadways. Average exposure in the former group was more than 64 decibels, compared with less than 45 decibels in the latter.

After adjusting for factors like age, sex, income, body mass index (BMI), alcohol intake, exercise, education, smoking, and other lifestyle habits, it was found that middle-aged adults living near the noisiest roads were nearly twice as likely to have high blood pressure. A similar pattern was found among people younger than 40 years, although the risks were not as high, and far fewer men and women that age had high blood pressure.

There was no link between traffic noise and high blood pressure among older adults. A possible reason could be that older people often have multiple risk factors for high blood pressure, any effects of noise exposure may be relatively small and harder to detect in a study.

The above findings add to the already existing evidence that chronic noise exposure may spell health trouble. This could be attributed to the fact that noise signals the body that it's in a stressful situation and chronic exposure may cause long-term increases in stress hormone production, heart rate and blood pressure.

The current findings do not prove that nearby traffic caused study participants' high blood pressure but suggest it might have been a factor in some cases. Further research is expected into the potential health effects of noise pollution at all ages.