In France, every year, according to the Ministry of Health and Solidarity, more than 140 thousand people suffer a stroke. in home women who live longer, Stroke is the leading cause of death, before breast cancer.
Air and noise pollution
But what is the relationship between the occurrence of this pathology and the environment? Is there a link between strokes and having a greener environment near the house? This is what the Spanish researchers wanted to know. A few years ago, this team from Hospital del Mar in Barcelona had already provided evidence of a link between air and sonic assaults and the risk of stroke. All of these factors air pollution and noise, act as stroke triggers, according to the researchers. This time, they wanted to go further and compare the epidemiological data with the presence of green spaces. Their results were published in early March in the journal “Environment International” (1).
The effect of particle levels
The study took into account information on exposure to three pollutants in more than 3.5 million people drawn from 7.5 million Catalans over the age of 18, who had not had a stroke prior to the start of the study (in 2017).
More specifically, the team analyzed the effect of particulate levels associated with vehicular traffic: particles less than 2.5 microns, nitrogen dioxide (NO2) and soot particles. They associated this level with the residence of each of the subjects studied. The number and density of green spaces within a radius of 300 meters around their homes were also studied.
Nitrogen dioxide is produced by road traffic
The results suggest several things, starting with the direct relationship between increased levels of nitrogen oxide2 atmospheric risk of stroke. Thus, for each increment of 10 micrograms (µg/m3) This risk increases by 4%. As with the other two types of particles studied, the risk increases. The scientists in the study explained that these numbers are the same for the entire population, regardless of other socioeconomic factors, age or smoking habits. Nitrogen dioxide is mainly produced by road traffic.
Reduce stress and increase physical activity
Therefore, the researchers’ conclusions are clear: “If we really want to reduce the multiple risks that this pollutant poses to people’s health, we must take bold measures to reduce the use of cars in the city.”
The second finding is the effect of the proximity of green spaces around the habitat. “Our study shows that people surrounded by higher levels of green space in their place of residence reduce the risk of stroke by 16%,” the scientists continued. Exposure to greenery is generally considered to have beneficial effects through a variety of mechanisms, such as stress reduction,Increase physical activity social contacts, and even exposure to a rich microbial ecosystem! The third lesson is more combative.
“We must achieve more sustainable towns and cities”
The study showed a risk of particle concentration levels lower, on average, than those determined by the European authorities, which are nonetheless considered safe! Despite complying with the levels set by the European Union, we are faced with the paradox that there are still health risks. There is a direct relationship between exposure to pollutants in our environment and the risk of stroke,” the study explains, with this sentence as the bottom line: “We should strive to achieve cities and towns more sustainable places to live that does not mean an increased risk of disease!” »
(1) “Ambient air pollution and greenery in relation to stroke: a population-based cohort study”, published in “Environment International”, March 2022.