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What Does 24 Hours Of Light Do To People?

What Does 24 Hours Of Light Do To People?

Human beings are biologically and culturally rooted to day and night in ways that don’t work
By Tim Edwards
Jun 09
From the June Issue Issue

In the early-2000s hit movie Insomnia, Will Dormer (played by Al Pacino) arrives in the fictional Alaskan town of Nightmute at the height of summer, called in from L.A. to help investigate the murder of a teenage girl. Dormer was losing track of time under the midnight sun from the moment he stepped off the plane. After accidentally shooting his partner in pursuit of the criminal, his guilty conscience keeps him awake at night, and any remaining chance of sleep is nullified by the constant sunlight. While the movie uses the midnight sun as a set piece, the effects of all that sunlight on the human mind aren’t too far off.

In 2001, a Milanese doctor released a study examining the effects of sunlight on patients with bipolar disorder, dividing his test subjects between east-facing and west-facing rooms. The patients in east-facing rooms, exposed to more direct sunlight in the morning, fared better on average than those on the other side. This finding has been bolstered by further studies, and had some basis in earlier research. In the summer, when sunlight is most plentiful, the human brain produces more serotonin (a neurotransmitter that affects mood) than it does in winter. People affected with bipolar disorder are often warned to stick to a healthy sleep routine when the seasons change to avoid “spring mania,” an increased likelihood of manic episodes corresponding to increased daylight. In the North, where the seasonal differences in sunlight are exaggerated to an almost ludicrous degree, this risk may be higher, and those with pre-existing mental conditions aren’t the only ones affected.

Jessa Gamble, a science writer in Yellowknife, has spent much of her career looking into circadian rhythms, which are physical and mental changes that mainly correspond to 24-hour cycles of light and darkness. Many of our internal processes follow a general internal clock, but some—such as the release of certain neurotransmitters and hormones—get their cues from light and darkness. Most people experience major disruptions in circadian rhythms in the form of jetlag: It’s not so much the adjustment to earlier or later waking times that cause the headaches and mental fog and indigestion, but the whole body’s adjustment to different cycles of light and corresponding rhythms for internal body temperature, hormone release, digestion and the like. In the Northern summers, Gamble says, the juxtaposition of drastic seasonal shifts and maintenance of the same old daily habits leave Northerners at risk of being perpetually jetlagged.

Stories abound of the haughty old British explorers neglecting to bring the basic necessities of Arctic survival and being found stumbling across sea ice half-mad, wearing military dress suited for summer in Great Britain. “Things that made sense in the heart of the colonial empire–everything that goes well in temperate zones–were exported to places where it doesn’t make any sense,” says Gamble, whose book on the subject, The Siesta and the Midnight Sun, goes as far as to wryly label the importation of the 9-to-5 workday to the seasonal extremes of the Arctic “circadian imperialism.” “This global, year-round schedule [...] never differs, even though the environment around us does and our bodies pull us in different directions than the established calendar timetable that we’re all supposed to be following.” The indigenous peoples of the North changed their lifestyles according to the seasons, but today everyone is just muscling through to maintain the same habits. “In the North specifically it’s almost this reductio ad absurdum of this circadian export, because it’s so patently ridiculous how non-seasonal the human rhythms are compared to the animal rhythms and the sun rhythms.”

So how to adapt? In the long-term, perhaps a reconsideration of the value in workweek homogeneity in vastly different climates. In the short-term, Northerners should invest in some black-out blinds. We’ve adapted slightly for the abundant darkness and abundant sunlight by turning indoor lights on in the morning and off at night, and in the summer closing the blinds or curtains. But it’s important to know how far those measures go: typical artificial light is much less effective in influencing our rhythms than is the powerful light of the sun, and normal blinds still let in an ambience of that powerful light—which is why you’ll see black curtains or aluminum foil on the windows of apartments in Iqaluit or houses in Dawson City when the sun is at its summer heights.

Sun and skin

“People have had burns on the roofs of their mouths—a friend of mine did—because they were breathing hard [heading] to the south pole, mouth open and the sun bouncing off the snow onto the roofs of their mouth,” says Ewan Affleck, a Yellowknife-based family physician (and member of the Order of Canada).

While he prefers to wear a hat rather than rely too heavily on sunscreen, Affleck does advise staying protected against the sun’s rays while it hangs perpetually in the sky. Even though sunlight is coming at an indirect angle, compared to areas closer to the equator, the longer periods of exposure do carry heightened risk. And the ozone, which blocks enough of the sun’s ultra-violet rays to allow for life on Earth, was weakened by the use of aerosols in the last century, particularly in the North.
(Though it is recovering).