In our modern world, 80% of the world’s population lives in environments where the light pollution. And this intense artificial night light of the cities “pregnant” strokes as it is associated with an increased risk of diseases that negatively affect the smooth flow of blood to the brain. That’s according to a new large Chinese study published in the American Stroke Association’s journal Stroke.
From the first studies of the species
Although previous studies have linked increased exposure to artificial light of cities at night with developing cardiovascular disease, the new study is one of the first to explore the link between exposure to light pollution and risk specifically for stroke.
“Although progress has been made in reducing ‘traditional’ cardiovascular risk factors such as smokingthe obesity and type 2 diabetesit is important to take environmental factors into account in the effort to reduce the global incidence of cardiovascular diseases” he said Jian-Bing Wangone of the study’s authors, a researcher in the Department of Public Health and the Department of Endocrinology at Zhejiang University School of Medicine Children’s Hospital and the National Child Health Clinical Research Center in Hangzhou, China.
Survey of tens of thousands of people
To reach their conclusions, the researchers studied data on 28,302 adults. Exposure to outdoor night light was assessed based on satellite imagery mapping light pollution. Stroke cases were confirmed through the patients’ medical records.
The analysis was conducted from 2015 to 2021 and included adults not previously diagnosed with cardiovascular disease who lived in Ningbo, an industrial city and major port on China’s east coast with a population of more than 8.2 million. The average age of the participants was 62 years and about 60% of them were women. Participants were followed for up to six years for possible cardiovascular disease, ischemic stroke and hemorrhagic stroke.
“Explosion” of… bright danger
Based on the findings, of all participants, 1,278 people experienced cardiovascular disease, including 777 cases of ischemic (due to a blood clot) stroke and 133 cases of hemorrhagic stroke.
The analysis found that people who had the highest levels of exposure to nighttime city light had a 43% increased risk of stroke compared to those who had the lowest levels of exposure to nighttime artificial outdoor light.
Environmental pollution is also “guilty”.
Environmental pollution also appeared to be a major “enemy” of brain health, according to the study. Specifically, as the results showed, the people who had the highest levels of exposure to PM2.5 microparticles in the atmosphere (which are released mainly from car exhausts but also from burning wood) faced a 41% increased risk of vascular disease of the brain compared to those with the lowest levels of PM2.5 exposure.
In addition, those with the highest levels of exposure to PM10 microparticles (larger diameter particles that come primarily from dust and smoke) had a 50% increased risk of cerebrovascular disease compared to those with the lowest levels of exposure to these particulates in the atmosphere .
At the same time, participants with the highest exposure to nitrogen oxides (emissions from cars, trucks and buses, industrial plants, etc.) faced a 31% increased risk of cerebrovascular disease compared to those with the lowest exposure to these atmospheric pollutants.
The combination that hits the brain
Additional analysis that included both nighttime light pollution and air pollution showed that associations with increased risk of cerebrovascular disease remained strong – except in the case of ischemic stroke.
Reduce exposure to artificial light
“Our study suggests that higher levels of exposure to outdoor artificial light at night is a potential risk factor for cerebrovascular disease,” noted Wang, adding that “based on the findings, we recommend that the population, especially those living in urban centers, try to reduce their exposure to artificial light at night in order to protect themselves from its possible harmful effect.”
Dysregulation of the body’s “internal clock”.
Artificial light sources include fluorescent light, incandescent lights, and LED lights. Continuous exposure to these light sources at night can suppress the production of melatonin, the sleep-promoting hormone, which in turn can disrupt the body’s internal “clock”, the circadian rhythm and lead to sleep problems. People who experience sleep problems face an increased chance of cardiovascular disease in the long term. “We need to develop more effective preventive strategies to reduce the negative health effects that environmental factors such as light and air pollution can have, especially for people living in the most densely populated and polluted areas of the planet.” concluded Dr. Wang.
#light #pollution #cities #pregnant #strokes
