Traffic noise and your blood pressure

For those thousands who are on the road every week day, have you ever wondered about how traffic affects your cardiovascular health? I already have tackled several aspects of traffic before in this blog and how they affect health. Here’s an update and another aspect of traffic we haven’t thought about yet – noise pollution.

Air pollution

Vehicular traffic generates air pollution. Environmental problems aside, many studies have shown that air pollution affects the heart, the brain, and the immune system, leading to chronic physical health problems such as asthma and heart disease as well as cognitive problems in children. See previous posts for a comprehensive of the global air pollution problems.

Stress

You cannot deny it. Driving to and from work and getting stuck in the traffic jam generates stress. Researchers have linked increased incidence of heart attack to heavy traffic and have found indication os synergy between stress and air pollution.

Noise pollution

It’s not only what you smell and what you feel – it’s also what you hear. In a recent study by Swedish researchers, traffic noise is also associated with cardiovascular effects that lead to increased blood pressure. According to lead author Theo Bodin of the Lund University Hospital,

“Road traffic is the most important source of community noise. Non-auditory physical health effects that are biologically plausible in relation to noise exposure include changes in blood pressure, heart rate, and levels of stress hormones. We found that exposure above 60 decibels was associated with high blood pressure among the relatively young and middle-aged, an important risk factor for cardiovascular diseases such as heart attack and stroke.”

The researchers looked at 27,963 residents of Scania, Sweden and the effects of road traffic on their health. Results of the survey showed:

• Exposure above 60 dBA (decibels) led to changes in cardiovascular parameters, most especially elevated blood pressure.
• All age groups were exposed to traffic noise levels below 60 dBA, a level which is considered moderate.
• Effects of traffic noise were more noticeable in young- and middle-aged members of the population and less in older age groups (e.g. 60 to 80-year olds).

The authors hypothesize on the reason for the different responses between age groups:

“The effect of noise may become less important, or harder to detect, relative to other risk factors with increasing age. Alternatively, it could be that noise annoyance varies with age”.

Sweden is comparably sparsely populated relative to many other developed countries. Scania is also a relatively small city by European standards. Can you imagine the amount of traffic noise that residents of large cities like Mexico, Sao Paolo, London, or Bangkok are exposed to? In the European Union alone, 30% of the population are exposed to day-night traffic average noise of 55dB(A). So next time you are tempted to press the accelerator or the horn, think about your health and that of others. Think about heart and your blood pressure.