“Most people consider artificial light at night to be harmless or even beneficial (e.g., from a safety perspective). However, light pollution has detrimental consequences for the environment, behavior, biology, and health. Exposure to outdoor artificial lighting at night is associated with numerous harmful health effects, including sleep disorders, obesity, depression, anxiety, memory dysfunction, atherosclerosis, and cancer,” the authors write in an article published in the professional journal Frontiers in Neuroscience.
However, little is known about the impact of light pollution on the development of Alzheimer’s disease (AD), which accounts for 60-80% of dementia cases and is estimated to affect 10.8% of adults over 65 years of age.
Over the past few decades, the prevalence of AD has been increasing, corresponding with an increase in light pollution, the scientists noted. Several studies in recent years have confirmed this link, finding that people living in areas with brighter nighttime lights in China and Italy have a higher risk of developing mild cognitive impairment and late-onset dementia.
A University of Chicago study assessed the relationship between asthma prevalence and average nighttime light intensity (light pollution) in the United States (including 48 states with lower light levels). The level of light pollution was assessed in several ways, including measurements taken from satellites.
The results confirmed expectations: average light intensity at night was associated with a higher prevalence of Alzheimer’s disease. The authors of the article did not give specific recommendations; they only identified the problem.
Overall, however, the need to sleep at night in complete darkness, using light-blocking curtains or at least a mask, was further confirmed.
