The Effect of Prolonged Lack of Daylight for Chilean Miners

Oct. 18, 2010
According to Samer Hattar, an assistant professor of biology at The Johns Hopkins University and an expert in how exposure to light (or lack thereof) affects mammals’ biological clocks and health, the 69 days the Chilean miners spent without natural light could impact their physiology, especially their sleep-wake cycles.

“The thing to remember is that we need exposure to light in order for our internal clocks – the mechanism that sets our sleep-wake cycle and regulates our moods, metabolism and so on – to function properly,” Hattar said. “The miners didn’t have that. As a result, for all intents and purposes, their biological clocks just kept running, which undoubtedly threw off their sleep-wake cycles.”

The miners’ well-publicized efforts to adhere to strict sleep-wake schedules (one group slept while the others were awake, and vice versa) may have helped them organize their day, but would have had no discernible impact on their biological clocks, Hattar said.

“There is no evidence that sticking to a regular schedule of sleeping and waking the way these men did would have any positive effect on the mechanism that our bodies use to set our internal clocks,” he said.

Long-term interruption of those circadian rhythms has been linked to symptoms ranging from depression and mood disorders to insomnia, metabolic and hormonal disturbances, headaches, impaired concentration and even diabetes and cancer.

Fortunately for the miners, the cure is easy.

“The miners need to be sure to expose themselves to natural light at the correct time of day – daytime – to readjust their clocks and receive the necessary photons to enhance their moods,” Hattar advised. “We don’t know precisely how long it will take them to completely reset their clocks, but it could be any time from a few days to a week or more.”

About the Author

Laura Walter

Laura Walter was formerly senior editor of EHS Today. She is a subject matter expert in EHS compliance and government issues and has covered a variety of topics relating to occupational safety and health. Her writing has earned awards from the American Society of Business Publication Editors (ASBPE), the Trade Association Business Publications International (TABPI) and APEX Awards for Publication Excellence. Her debut novel, Body of Stars (Dutton) was published in 2021.

Sponsored Recommendations

Committing to Safety: Why Leadership’s Role in Safety Excellence is Key

Jan. 13, 2025
Leadership has the power to transform an organization through their behavior and vision, which can result in the creation of an organizational culturethat supports safety excellence...

Speak Up! Cementing "See Something, Say Something" to Drive Safety

Jan. 13, 2025
Many organizations promote "see something, say something" to encourage their people to intervene and make work safe. But most don't go far enough to equip teams with the skills...

The Truth and Challenges of Cultivating Chronic Unease

Jan. 13, 2025
DEKRA announces its latest white paper, “The Truth and Challenges of Cultivating Chronic Unease,” as a definitive look into why being vulnerable to incidents strengthens our commitment...

Mitigating Risks: Strategies for Safeguarding Workers in Hazardous Workplaces

Jan. 13, 2025
Join our expert team in taking on the challenge to make safety part of your organization’s DNA as work, the workforce, and workplaces evolve.

Voice your opinion!

To join the conversation, and become an exclusive member of EHS Today, create an account today!