Scientists have found a link between the noise of cars, dirty air and high blood pressure

If you constantly have to complain about the dirty air in your area, and the noise of cars outside the window, there is a risk that the encounter with hypertension in the future. That is the conclusion reached by researchers, who for nine years analyzed data more than 41 thousand people in five countries.

The results of this large-scale study published in the European Heart Journal on 25 October. They showed that every hundredth person living in a dirty area of developing hypertension. The noise and dirty air given the same risk as overweight a person, body mass index (BMI) which is in the range of 25-30. The researchers note that high blood pressure - one of the most important risk factors for premature illness and death.

This study - the first of its kind, where both studied the effect of dirty air and traffic noise on human health. The researchers found that traffic noise is associated with an increase in the number of hypertensive patients. They also assessed the risks associated with noise, apart from the dirty air.

In total, the study involved 41,072 people from Norway, Sweden, Denmark, Germany and Spain. It became part of the project ESCAPE (European Study of Cohorts for Air Pollution Effects), which examines the long-term effects of exposure to polluted air on human health in Europe. In the first phase, volunteers provided information on the state of the pressure. When they joined the study, none of them suffered from high blood pressure. In subsequent years, all the participants were regular surveys. After analyzing the data, the researchers calculated that of all the volunteers in 6207 (15%) diagnosed with hypertension. They appointed medications that lower blood pressure.

In 2008-2011, near the homes of participants adverse conditions have been created artificially. The process is divided into three two-week period, taking into account seasonal effects. The researchers modeled the concentration of contaminants - particulate matter (TM). Such particles can be of different sizes. For example, PM10 - particles is less than or equal to 10 microns in diameter. Similarly PM2.5 (less than or equal 2,5mkm). There are coarse PM (PM10 minus PM2.5) and PM 2.5 optical density (soot particles). All of them were used in this experiment. The solids were analyzed in 20 sections of each country. Even in 40 different areas with land-use regression, the concentration of nitric oxide. As regards traffic noise, the density of an automobile stream and hum created near the homes of participants under the rules established by the EU Directive.

The researchers found that in areas where the concentration of PM2.5 5mkg / m3, the risk of hypertension increased by 22% compared to the cleaner areas. Higher concentrations increase the likelihood of the disease even more. The inhabitants of the houses, where the average level of noise on the street at night is 50 dB, the risk of cardiovascular disease increased by 6%. For comparison, conversation varies from 45 to 60 dB, depending on the volume of voice and noise intensive traffic often does not exceed 80 decibels. From this we can conclude that the potential exposure to cardiovascular disease is, even where the noise level does not exceed the limit established by the EU Directive.

This is a very important aspect, since the current legislation does not protect the European population from the adverse effects of traffic noise. Scientists believe that the results of the study are important for public health and require more stringent restrictive regulations.

It is known that when a person is doing something, prolonged exposure to noise reduces the concentration and increases the likelihood of errors. In addition, noise may interfere with the metabolism, affects the nervous system, cause ulcers and other diseases. Too loud noise (over 100 dB) leads to rupture of the tympanic membrane. As a result of the hearing, or greatly reduced, or deafness occurs.

According to the study, "leaders" in the transport noise and car traffic density areas were Sweden and Spain. The highest average level of pollution is observed in the Central and Southern Europe - Germany and Spain. In Norway, Sweden and Denmark on the streets quiet.

Professor of environmental epidemiology at the University of Düsseldorf, Barbara Hoffman, who conducted the analysis confirmed that prolonged exposure to particulate air pollution is associated with increased incidence of hypertension. And since almost all of us throughout life are at risk affected by dirty air, make the risk of health problems is large enough.

There is a possibility that dirty air and noise have different effects on the normal functioning of the body, or only partially coincide. Possible biological consequences of the negative impact of dirty air on the functioning of the vessels of the heart and blood vessels include local and systemic inflammation, oxidative stress and disorders of the nervous system.