Light Pollution at Night May up Insomnia Risk in Elderly

Increased exposure to artificial or outdoor light, referred to as light pollution, at night can significantly raise the risk of developing insomnia in older adults, say researchers.

The study, led by researchers from the Seoul National University in South Korea, showed a strong correlation between increased levels of night-time lighting and the number of prescriptions for hypnotic drugs also known as sleeping pills.

In addition, older adults exposed to higher levels of outdoor light pollution at night were more likely to use hypnotic drugs for longer periods or receive higher doses daily.

"This study observed a significant association between the intensity of outdoor, artificial, night-time lighting and the prevalence of insomnia as indicated by hypnotic agent prescriptions for older adults," said Kyoung-bok Min, Associate Professor at the varsity.

"Our results support the data that outdoor, artificial, night-time light could be linked to sleep deprivation among those inside the house," Min added, in the paper published in the Journal of Clinical Sleep Medicine.

According to the American Academy of Sleep Medicine, insomnia can involve struggling to fall asleep, having trouble maintaining sleep, or waking up too early.

A variety of environmental factors including excessive noise or light and extreme temperatures will disrupt the sleep of most individuals.

Light pollution has emerged as a novel environmental factor linked to human health. Studies have also showed that artificial night-time lighting, whether indoor or outdoor, induces disruption of circadian rhythms, potentially leading to metabolic and chronic diseases, including cancer, diabetes, obesity and depression.

For the study, the team included 52,027 adults aged 60 years or older among which about 60 per cent of the participants were female.

Min added that while public health officials seem to be less concerned with light pollution than with other environmental pollutants, this study strengthens the potential link between light pollution and adverse health consequences.

More studies and public policy initiatives are needed to define and minimise the adverse effects of light pollution on human health, the researchers noted.