Pollution increases the risk of stroke, but also the severity of these strokes. Specifically, and according to a study conducted by the Hospital del Mar Institute for Medical Research (IMIM) in Barcelona, ​​living in areas with high noise levels increases the chances of suffering a more serious stroke and more complex sequelae by 30%. Instead, residing near green environments reduces this risk by 25%.

IMIM researchers, who have published the finding in the scientific journal Environmental Research, recruited about 3,000 patients who had been treated at the Hospital del Mar in Barcelona because of a stroke between 2005 and 2014. Scientists had already proven that Pollution influenced the risk of stroke, but they wanted to know if noise and air pollution also played a role in the severity of this condition, which is the leading cause of disability in adults.

Together with scientists from the ISGlobal in Barcelona and Brown University, in the United States, the experts geolocated the patients and analyzed their exposure to noise, pollution levels in their surroundings and the proximity to green spaces. “We used data from the Cartographic Institute of Catalonia, models to analyze pollution levels, the noise map of Barcelona and satellite data to define green areas,” says Dr. Rosa María Vivanco, researcher at the IMIM Research Group and First author of the study.

The result of the investigation found that noise and proximity to green areas influence the greater or lesser severity of the stroke. “We have seen that, more green spaces, less stroke severity and, more noise, more seriousness. The stroke leaves fewer sequelae if you detect it as soon as possible, but also if it is milder, recovery is greater. The environment influences the burden of disease,” explains Vivancos. The average noise level to which the patients included in the trial were exposed was 66 decibels. The World Health Organization (WHO) argues that, after 53 decibels, there may already be health effects.

According to the researcher, the origin of this link would be in the inner layer of blood vessels. Stroke is a condition that is characterized by an obstruction of the cerebral vessels and exposure to noise can make that inner layer of the vessels, which is responsible for blood flow, malfunction. “In addition, noise increases the peaks of hypertension, which is another parameter related to the risk of stroke,” adds the researcher.

What has not been confirmed, however, is the role that air pollution plays in the greater or lesser risk of suffering a serious stroke. “Our data is inconclusive because there is no exposure variability,” says Vivancos. The levels of contamination to which the patients studied were exposed hardly suffered variations and the data collected does not allow conclusions to be drawn. “Pollution zones have little difference, but we cannot say that pollution does not influence. We must investigate further,” adds the researcher.

 

Source: El País