Shift work increases the risk of cancer among those on the graveyard shift

You might expect shift work to cause insomnia, irritability, absenteeism, an increase in accidents on the job, and so on, and it does–especially for people on the third shift, which typically occurs from 10 p.m. to 6 a.m. However, when the graveyard shift disrupts circadian rhythms, it not only causes many expectable problems, but also increases the risk of cancer. Consequently the World Health Organization has tentatively classified the graveyard shift as a possible carcinogin.

Negative Air Ions

What are negative air ions? Where do you find them? And what do they have to do with the romance of Niagara Falls, the fun of a day at the beach, or the glory of a tropical rain forest?

Negative air ions are created when an electron–a tiny particle with a negative charge–piggybacks onto a big molecule of oxygen. The molecule of oxygen, which has no charge before this event, then carries a negative charge. The oxygen continues to carry a negative charge if microscopic drops of water surround it and its visitor, preventing the electron from leaving.

At Niagara Falls, beaches, and tropical rain forests, as well as anywhere there is a storm, the moisture in the air tends to keep an extra electron on zillions of oxygen molecules. These charged oxygen molecules turn into the equivalent of miniature vacuum cleaners by attracting dust, smoke, pollen, mold spores, and other unwanted particles which have positive charges, since negative particles attract positive particles. When the charged oxygen molecules attracts positive particles, they form heavy clumps, which drop to the ground, leaving the air we breathe fresher and cleaner.

Negative air ions occur far more often in nature than in our homes and buildings, where heating systems and air conditioners remove moisture from the air, making it hard for electrons to stick to oxygen molecules. People can buy ionizing air cleaners to reverse this problem, but need to be sure the machines are powerful enough to have an effect, since often only industrial-strength ionizers are effective.

Perhaps more important, negative air ions can relieve depression and enhance sleep quality if used properly as a treatment for these problems. For example, an experiment at Columbia University found that the mood and sleeping problems of people who received high-density negative air ions improved just as much as they did in people who received bright light therapy, a treatment that had already been proven effective.

What remains a mystery about negative ions, however, is how they work. Scientists suspect the effects may be linked to the ease with which ionized air moves from the lungs throughout the body, improving circulation.

New York Teenager on California Time

Did Jonathan do drugs? Did he suffer from anxiety? Did he have attention deficit hyperactivity disorder (ADHD)? While his teachers didn’t know what was wrong with Jonathan, age fifteen, they did know his tendency to fall asleep in their classes was a problem.

Jonathan’s parents were baffled, too. Finally, when Jonathan consistently wouldn’t get up in the morning, his father decided Jonathan didn’t really want to get up. His mother, on the other hand, would sometimes baby Jonathan, and sometimes try tough love. For a while, when he was young, she would sleep in his room, because her presence soothed him. Later, she would leave him alone to cry himself to sleep at night, or pick him up out of bed, and put his feet on the cold bathroom floor, to wake him up for school in the morning. Indulgent or strict, either way, she wound up feeling guilty, and worried she was doing the wrong thing.

But the culprit in this case was not Jonathan’s mother, but Jonathan’s sleep pattern. And the mystery inched closer to a solution during one lazy summer vacation after Jonathan’s parents divorced. Without obligations to keep Jonathan on a schedule, his mother thought, “I wonder what kind of sleeping timetable Jonathan would have if I didn’t try to make him go to bed, and get up, at particular times.”

The results of her experiment surprised her. For the first week, Jonathan slept from 1 AM to 1 PM. That was followed by a second week of sleeping from 2 AM to 2 PM, a third week of sleeping from 3 AM to 3 PM, and so on. Thus although teenagers need a great deal more sleep than adults, Jonathan needed a great deal more sleep than even the average 9.2 hours per night that most adolescents require. But why was Jonathan naturally gravitating towards later and later bedtimes?

Jonathan and his mother found out by chance, when they saw an article about sleep and circadian rhythms in The New York Times. The article was by psychologist Michael Terman, a pioneer who applies research about the body’s natural rhythms of activity to everyday problems.

When Jonathan and his mother visited Dr. Terman, he gave them very specific advice about how to use light therapy to reset Jonathan’s cycle of sleep and wakefulness, and continue to use a small amount of light therapy daily to stay on a good schedule. Specifically, Dr. Terman gradually adjusted Jonathan’s bed-time from the wee hours of the morning to an evening hour that was more in tune with his family, friends, and school. Then Dr. Terman showed Jonathan how to maintain this schedule with light therapy and structured time.

Resetting one’s internal clock is more of a challenge than it sounds, but it was necessary because, as Dr. Terman put it, Jonathan was physically in New York, but his circadian rhythm was three hours ahead, on “California time.”

The effects of light therapy for Jonathan were striking. Jonathan reports that this simple, non-intrusive intervention enabled him to stay awake in all his classes, and enjoy an improvement in his grades. This treatment also gave him a sense of control over his therapy, since he felt that if he took medication, he would be dependent on pills. On the other hand, the light box fascinated him.

Jonathan’s ownership of his problem made his mother proud of him, but her real satisfaction with treatment lay in the results. Before light therapy, she said, Jonathan was like a drooping plant that hadn’t been watered for a long time. Resolving his sleep problem was like watering that plant, like bringing half-dead leaves to life in Louisville, Kentucky. It was solving the problem of the New York teen on California time.

Light Therapy on the Wild Side

In the quest for novelty and consumer interest, some companies have turned away from bright white light boxes (the clinically-tested standard). Ill-advised variations include miniaturization and head or eyeglass mounts. Green and blue have been substituted for white on the doubtful supposition that the antidepressant effect would be enhanced.

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