Researchers used ultrasound to examine the extent to which blood vessels expand and contract with each heartbeat. Among the results, a difference in the volunteers' sensitivity to noise was found. This can include setting speed limits in populated areas at 30 km/h and creating green spaces as sound barriers between homes and car tracks on streets. The leader of the study, Montsel, stated: "Noise protection is protection for blood vessels. Every decibel reduced means less stress on the blood vessels, less inflammation in the blood, and in the long term, fewer cases of heart attacks and strokes." A total of 74 people aged 18 to 60 participated in the study. They were also prohibited from consuming caffeine and nicotine during the study period. The next morning, heart and blood vessel indicators were measured, and blood samples were examined for inflammatory proteins. However, overall, the functional and biological changes were clear after just one night of exposure to traffic noise, according to the study led by Thomas Montsel at the University Medical Center Mainz in Germany. These symptoms included an increased heart rate, changes in proteins, and decreased elasticity of blood vessels. The latter is considered an early indicator of vascular health, according to the researchers. Research has long pointed to the negative impact of environmental noise on health, which the World Health Organization classifies as "one of the major environmental risks to physical, mental health, and well-being." In Germany, where the research was conducted, about 2.3 million people (approximately 2.7% of the population) are exposed to noise levels exceeding 65 decibels during the day, and 2.6 million people (3% of the population) are exposed to levels exceeding 55 decibels at night. In light of these results, researchers called for continuous protection from noise. Noise pollution from traffic is an increasing threat to health, as a recent study showed that even moderate traffic noise on roads can affect the heart and circulatory system with just one night of exposure. In the study, published in late February in the journal Cardiovascular Research, German researchers simulated different conditions in the bedrooms of 74 participants aged 18 to 60. The study included nights without additional noise and other nights when traffic noise was played through speakers 30 or 60 times for one minute and 15 seconds each time. The sound level ranged from 41 to 44 decibels, which is equivalent to the level of a quiet conversation. The participants were not previously aware of whether they would be exposed to a certain sound level or to which level.
