Emily Chan
Even at night, the lights always stay on in some places. Street lamps, roadway lighting, and illuminated signs can make roads safer and discourage crime. However, excessive lights at night can lead to health and environmental consequences.
When the lights never go off, this creates light pollution. In a new study, researchers have identified a correlation between nightly light pollution and Alzheimer’s disease (AD) in the United States. Exposure to light pollution at nighttime may increase the risk of developing Alzheimer’s.
“We show that in the U.S., there is a positive association between AD prevalence and exposure to light at night, particularly in those under the age of 65,” said Dr. Robin Voigt-Zuwala, the first author of the study and an associate professor at Rush University Medical Center.
“Nightly light pollution—a modifiable environmental factor—may be an important risk factor for AD.”
The researchers studied data from satellites to determine the average intensity of lights at night in the U.S. between 2012 and 2018. They ranked the lower 48 states from the lowest to the highest nighttime light intensity.
The results revealed that the prevalence of Alzheimer’s was more strongly linked to nightly light pollution than other disease factors for people aged 65 and older.
Some of the disease factors included obesity, depression, alcohol abuse, and chronic kidney disease.
Other risk factors, such as stroke, high blood pressure, and diabetes, had a stronger correlation with Alzheimer’s disease than light pollution.
However, for people under the age of 65, a higher intensity of light pollution at night was associated with a greater prevalence of Alzheimer’s than any other risk factor that was examined in the study.
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