Living near a busy road could cause high blood pressure, according to the largest study yet carried out on the effects of air pollution and traffic noise.
The study, which has been published in the European Heart Journal, follows observation of 41,072 people in five European countries (Germany, Spain, Norway, Sweden and Denmark) for between five and nine years.
It was found that long-term exposure to air pollution is linked to a greater incidence of high blood pressure, and that one extra person per 100 people living in the most polluted areas of a city will develop hypertension. This risk is similar to the effect of being overweight (having a body mass index between 25-30).
The researchers found that for every five micrograms of polluting particles per cubic metre, the risk of hypertension increases by 22 per cent. People living in noisy streets, where there were average night time noise levels of 50 decibels, had a six percent increased risk of developing hypertension compared to those living on quieter streets.
Professor Barbara Hoffmann, who led the analysis, said: ‘Our findings show that long-term exposure to particulate air pollution is associated with a higher incidence of self-reported hypertension and with intake of anti-hypertensive medication. As virtually everybody is exposed to air pollution for all of their lives, this leads to a high number of hypertension cases, posing a great burden on the individual and on society.’
‘Exposure to traffic noise shares many of the same sources with air pollution and so has the potential to confound the estimates of the adverse effects of pollution on human health. However, this study controlled for traffic noise exposure and found that the associations of air pollution with hypertension did not vanish. This is important because preventive measures for air pollution and noise differ. ‘
‘One very important aspect is that these associations can be seen in people living well below current European air pollution standards. This means, the current legislation does not protect the European population adequately from adverse effects of air pollution.’
According to the World Heart Federation, high blood pressure is the most important risk factor for premature illness and death.
The various factors that can raise blood pressure are well known and often quoted but this study suggests another should now be added to the list – living near a busy road.
Over 40000 people in 5 different European countries were studied for 9 years in the world’s biggest study into the health impact of air and noise pollution. The researchers found that people living in noisy streets had a 6% increased risk of developing raised blood pressure compared to those living in quieter streets, and that those exposed to the higher air pollution were 22% more likely to have developed hypertension than those in the least air polluted areas.
Why air pollutants should increase blood pressure remains unclear but exposure to traffic noise shares many of the same sources with air pollution. This is an important study with significant implications but whether you can do anything about living on a busy road is another matter altogether.