Our research group recently took a trip up to the John Day Fossil Beds National Monument in Eastern Oregon. According to the CIRES atlas of artificial sky brightness the surrounding area is supposed to encompass some of the darkest skies in Oregon.
I was looking forward to sleeping out under the stars for the first time in a long time. I was imagining that I would lay down and gaze up at the starry sky as I was falling asleep, but ironically a nearby streetlight, which was supposed to illuminate the path to the bathroom, was so bright that it disrupted both my stargazing and my sleep.
Artificial light affects human lives more than most people realize. Sleep cycles are controlled by the circadian clock located in a cluster of nerves called the suprachiasmatic nuclei (SCN) in the brain. The circadian clock regulates sleep based on a light detection system located in the eye. For the last 200,000 years our bodies’ sleep cycles have been dictated mainly by the earth’s natural light cycles. In modern civilization, however, our sleep patterns are affected by artificial lights such as street lights, interior lights, and LCD screens.
The circadian clock has many effects that do not directly involve sleep cycles. It affects one’s hormone production and metabolism, which is why people who get less sleep are more likely to be overweight. Sleep disorders, narcolepsy, jet lag, and wintertime depression are all a result of problems in the SCN. Some of the “clock genes” that are a part of one’s circadian clock are involved in cell proliferation and cell suicide, which are both key functions in cancer, leading some researchers to think that these genes could play a role in curing the disease. [1] Additional support for the idea that disruption of the circadian rhythm by artificial light has connections with cancer comes from researchers in Israel who have found that “women living in neighborhoods where it was bright enough to read a book outside at midnight had a 73% higher risk of developing breast cancer than those residing in areas with the least outdoor artificial lighting.” [2]
In addition to being affected by streetlights, many people are affected by artificial light from phones, tablets, televisions, and laptops. Blue light, which is prevalent in LCD screens, is especially disruptive to our circadian rhythms. This type of light signals the brain to stop producing melatonin, the sleep regulating hormone. Recently, applications like Twilight and Lux have been introduced, which claim to improve the sleep of the user by dimming screens depending on the time of day and the brightness of the surrounding environment. iOS 9.3 has a Night Shift mode that eliminates the harmful blue light, giving the screen more of an orange glow, which will help people who spend time on their phones or tablets before bed. [3]
If you're interested in reading about how artificial light affects other animals then check out our post about bats and stay tuned for the results of our research on the affect of artificial light on mayflies.
[1] "The Time of Our Lives." Genetic Science Learning Center. University of Utah, n.d. Web. 19 July 2016.
[2] Chepesiuk, Ron. "Missing the Dark: Health Effects of Light Pollution." Environmental Health Perspectives. National Institute of Environmental Health Sciences, 2009. Web. 19 July 2016.
[3] Alban, Deane. "How Artificial Light Is Ruining Your Sleep (And What You Can Do About It) - Reset.me." Resetme. N.p., n.d. Web. 19 July 2016.
I was looking forward to sleeping out under the stars for the first time in a long time. I was imagining that I would lay down and gaze up at the starry sky as I was falling asleep, but ironically a nearby streetlight, which was supposed to illuminate the path to the bathroom, was so bright that it disrupted both my stargazing and my sleep.
Artificial light affects human lives more than most people realize. Sleep cycles are controlled by the circadian clock located in a cluster of nerves called the suprachiasmatic nuclei (SCN) in the brain. The circadian clock regulates sleep based on a light detection system located in the eye. For the last 200,000 years our bodies’ sleep cycles have been dictated mainly by the earth’s natural light cycles. In modern civilization, however, our sleep patterns are affected by artificial lights such as street lights, interior lights, and LCD screens.
The circadian clock has many effects that do not directly involve sleep cycles. It affects one’s hormone production and metabolism, which is why people who get less sleep are more likely to be overweight. Sleep disorders, narcolepsy, jet lag, and wintertime depression are all a result of problems in the SCN. Some of the “clock genes” that are a part of one’s circadian clock are involved in cell proliferation and cell suicide, which are both key functions in cancer, leading some researchers to think that these genes could play a role in curing the disease. [1] Additional support for the idea that disruption of the circadian rhythm by artificial light has connections with cancer comes from researchers in Israel who have found that “women living in neighborhoods where it was bright enough to read a book outside at midnight had a 73% higher risk of developing breast cancer than those residing in areas with the least outdoor artificial lighting.” [2]
In addition to being affected by streetlights, many people are affected by artificial light from phones, tablets, televisions, and laptops. Blue light, which is prevalent in LCD screens, is especially disruptive to our circadian rhythms. This type of light signals the brain to stop producing melatonin, the sleep regulating hormone. Recently, applications like Twilight and Lux have been introduced, which claim to improve the sleep of the user by dimming screens depending on the time of day and the brightness of the surrounding environment. iOS 9.3 has a Night Shift mode that eliminates the harmful blue light, giving the screen more of an orange glow, which will help people who spend time on their phones or tablets before bed. [3]
If you're interested in reading about how artificial light affects other animals then check out our post about bats and stay tuned for the results of our research on the affect of artificial light on mayflies.
[1] "The Time of Our Lives." Genetic Science Learning Center. University of Utah, n.d. Web. 19 July 2016.
[2] Chepesiuk, Ron. "Missing the Dark: Health Effects of Light Pollution." Environmental Health Perspectives. National Institute of Environmental Health Sciences, 2009. Web. 19 July 2016.
[3] Alban, Deane. "How Artificial Light Is Ruining Your Sleep (And What You Can Do About It) - Reset.me." Resetme. N.p., n.d. Web. 19 July 2016.