Shift Work

ASLEEP AT THE SWITCH

By Mark Sabourin

Everyone has a bad night once in a while. Most shift workers can count on having one every day.

It's not like religion, or politics, or sex. Shiftwork is one of those subjects that can be raised anywhere, anytime and have all present quickly nodding their heads in agreement. It's a terrible way to organize work, say employers. It’s a good way to wreck your life, say workers. Health and safety officials tend to agree. Psychiatrists and psychologists can find little good to say about it.

There's another thing they agree on. As bad a system as shiftwork is, no one expects it to disappear. Some work, such as emergency services, hospital care and utilities maintenance, just has to continue around the clock. Some large industrial plants, with huge investments in plant and equipment, can’t afford to be left sitting idle for a half or a third of the day. As much as we might like to, we just can’t shut the world down for part of the day. Shiftwork is here to stay.

But people were designed to function, adapted by millions of years of evolution, to an intricate set of schedules and rhythms such as the changing seasons, the phases of the moon and, above all, the daily cycles of light and dark, of sleep and wake. Turn those cycles upside down and you’re asking for trouble. Switch them around every couple of weeks and you’re asking for big trouble.

Accident frequency rises overnight. Accidents spike the day after conversion to Daylight Saving Time. Fatigue-related vehicle collisions peak at two a.m., and many experts now believe that driving sleepy is as big a cause of accidents as driving drunk. And an astonishing list of major disasters all happened in the small hours of the night or early morning: Three-Mile Island, Chernobyl, Bhopal, Exxon Valdez, and the Hinton, Alberta train disaster.

What shiftwork does is shake up the intricate network of interrelated clocks and schedules that keep the human body functioning as efficiently as it does. One of the keys controlling this network of clocks and schedules -- the experts call them our circadian rhythms -- is a person's sleep-wake cycle. Mess with that, say the experts, and you throw everything else out of whack.

You would think that an activity that consumes roughly one-third of our lives -- sleeping -- would be well understood. But you would be wrong. What happens after the Sandman visits, and why, is still a deep, dark mystery to modern medical science. We’re still groping in the dark. We don’t even really know why we sleep.

But we do know for sure that sleep is essential. Sleep badly and you start functioning badly. Sleep badly over the long term and you fall prey to all manner of physical and psychological disorders.

You cycle through periods of deep sleep and REM (rapid-eye-movement) sleep, says Bob Hoffmann, research fellow in the Department of Psychiatry at the University of Texas Southwest Medical Centre. Within those cycles, patterns of activity emerge. The immune system kicks into high gear. Hormones are released. Repair crews are dispatched to various damaged parts of your body.

Late at night, the body's core temperature drops. The combination of a cooling body and a warm brain leads to what researchers call "slow-wave sleep" or deep sleep. It is this stage of sleep that researchers believe restores and rejuvenates the human body. Cycles seem to run every 90 minutes or so. Let the cycles complete themselves as they should, let the body stir when it feels the urge to waken, and you'll be ready to wake up rested, refreshed and prepared to face the day. As dawn approaches, core body temperature begins to rise, and we awaken. Body temperature continues to climb, reaching its peak around noon.

Workers coming off shift at 8 a.m. do battle against those natural rhythms. The light of dawn is a trigger that their bodies recognize as a wake-up call, says Ron Hesslegrave, research director in the Department of Psychiatry at Toronto's Wellesley-Central Hospital. And then their core body temperature is already rising. Even if they do fall asleep, they miss the slow-wave sleep that scientists believe is necessary to maintain alertness.

"I guarantee 75 per cent of them are awake at noon, when core body temperature peaks," says Jon Shearer, a consultant and former Carleton University professor.

Statistics put the shiftwork population at somewhere between 20 and 25 per cent of the work force, but Shearer figures the impact is felt by fully one-third of the working population, if not more. "And it affects virtually every single aspect of the human condition," he says.

Everyone has a bad night every once in a while. Most shift workers can count on having one every day. Ron Hesslegrave says people who work an overnight shift get a daily average of only four or five hours of sleep, and that's just not enough to keep a human being healthy, happy and functioning properly in the long run. His research has shown a 25 per cent drop in productivity in conditions of sleep deprivation equivalent to an overnight shift. The natural response of a tired worker is to slow the pace of work and try to maintain accuracy, he says. Where work is externally paced and the worker does not control the speed of the work -- such as on an assembly line -- Hesslegrave warns employers to expect an increase in accident frequency.

Cathy Walker, national health and safety director for the Canadian Auto Workers union, says this is more of an issue now than ever before because the pace of work is so much faster and workers are under increasing pressure to work overtime. "It's harder and harder for people to keep up," she says.

Her gravest concern -- one shared by practically all the experts -- is for workers engaged in "constant vigilance" jobs, such as driving down a highway, or monitoring a plant. Those tasks require a worker to maintain the same level of attention at all times, but, warns Ron Hesslegrave, workers lose that ability to attend over time, and overnight.

"For people in control rooms -- it doesn't matter if it's a nuclear reactor or a pulp mill -- most of the job is just looking at dials waiting for something bad to happen," says Walker. On day shifts, those workers are merely bored. On the night shift, they're also tired. "It's critical if someone is sound asleep when the red light is flicking," she says.

Don't for a moment think it doesn't happen, says Ron Hesslegrave. "People working overnight are sleeping. You just don't know it."

Given enough time, the body will adapt to the new rhythm, although experts are divided on how complete that adaptation will be. Two weeks into a new shift is when most workers should begin to feel comfortable with a new sleep-wake routine. Unfortunately, two weeks is also the length of many shift rotations. Just when your body settles into a new routine, it is forced to adapt to another.

Workers on steady nights have an advantage, says Bob Hoffmann. "When you have to wake up is the issue," he says. "Constantly changing that time is what causes problems." But, as Ron Hesslegrave points out, "Nobody who is a night shift worker remains a night shift worker on his days off." Whatever gains the body makes in adapting to the night shift will be lost during days off.

TRIPLE RED SIGNAL

Michael Darby is director of commuter operations for CN Rail, in charge of the GO Transit commuter service around Metro Toronto. The prospect of a moment's inattention clouding the mind of a locomotive engineer hurtling down a track at 80 miles per hour with 2,000 passengers in tow is enough to keep him awake at night.

"Some of our crews start at 4:10 in the morning. They've got to get up at 3:00 and work a split shift," says Darby, who came up through the ranks as a locomotive engineer. "I've done that a few times and I'll tell you, by the end of the day I'm dragging my rear end."

Darby, at least, is in a strong position to do something about it. Prior to his recent move to GO Transit, he was assistant vice president of safety for CN Rail, responsible in large part for the implementation of a fatigue countermeasures program across all of CN's operations.

CN is typical of the rail industry. Because freight train scheduling is virtually impossible, crews are constantly on call. The result can be painfully long hours, and short intervals between shifts. Darby says the company decided to re-examine its practices largely due to pressure from the federal government, which had grown concerned with the hours of work of train crews.

But there was also the spectre of an event that had happened 10 years earlier, a spectre born in the light of dawn, near a small town in Alberta called Hinton.

Twenty-three lives were lost on February 8, 1986, when a mile-long freight train plowed head-on into an oncoming Via passenger train with 115 people on board. To this day, no one knows for certain why the freight's engineer ignored the triple-red signal and allowed his train to charge onto the single track, directly into the path of the oncoming passenger train. Everyone who could answer that question died in the wreck. What we do know for certain is that the engineer had taken only four days off in the previous 30, that his crew had brought in another train earlier that morning, that they'd had maybe a few hours' sleep, and that they were all bone-tired.

CN's fatigue countermeasures program is part of a larger effort also involving Via Rail, CP Rail, and the Brotherhood of Locomotive Engineers. Fatigue countermeasures were settled upon because in the rail industry, as in so many others, there was little flexibility to change operations to eliminate fatigue.

Following the testing of train crews in a 1994 program called CanAlert, five countermeasures were settled on as most effective. First, and perhaps most important, a form of scheduling was introduced. Train movement still can't be predicted like a production line, but instead of being available seven days a week, 24 hours a day, crews are now given "windows of availability" within which they are on call.

Second, a "napping policy" is being tested. Experts told CN that a 20 minute nap might allow a crew member to function effectively for another couple of hours. The 20 minutes is important; more than that and you run into "sleep inertia", which would leave you groggy instead of refreshed.

Third, crews were given lifestyle training, including advice on human physiology, nutrition and proper sleep hygiene.

Fourth, rest houses were improved. White noise was introduced. Dark-out curtains were placed over windows.

Fifth, cabs were modestly redesigned. Music was allowed, with an automatic cut-out device that shut off the music when the CN two-way radio came on. More attention was paid to ergonomics, including fold-down seats to facilitate napping.

TWO HUNDRED SLEEPY WORKERS

If fear of ham-fisted government intervention is what got the railroads to address fatigue among workers, it was prudent management practices coupled with a startling realization that got the program rolling at NOVA Chemicals in Calgary. Two workers were on short-term disability from fatigue-related complaints. Fatigue was a growing issue. A look at employee demographics revealed an aging work force. The company decided it would be prudent to examine the impact of shiftwork and fatigue on its employees. The wisdom of this course of action became even more apparent when someone pointed out that in the middle of the night, $7 billion worth of company assets and gas worth $3.3 billion in revenues were entirely in the hands of only 200 sleepy workers.

NOVA's concern about its aging work force has merit, says psychologist Ron Hesslegrave. Among the positions lost during the economic restructuring of the last decade are the more sedentary office jobs to which older shift workers often gravitated. The shift-work force is aging, and the older you get, the more difficult shiftwork becomes.

So far, 95 per cent of NOVA's shift workers have received training under its Shiftwork Awareness Program (SWAP), says Wendy Joel, NOVA's occupational health and shiftwork consultant.

As part of its SWAP program NOVA has offered lifestyle counseling to shift workers and their families. Additional training in sleep disorders and shiftwork-related health issues has been offered by NOVA's health personnel. Periodic medical monitoring of employees now includes questions on fatigue-related disorders. The company is also reviewing administrative support services to ensure that they meet the needs of the shift work force. Among the issues being looked at are extending benefits coverage for fatigue-related therapies that are not covered by provincial health insurance; ensuring that health services and training programs are equally available to the shift work force; and additional retirement planning for younger shift workers, including the investment of shift premiums into early retirement options.

NOVA's 12-hour rotating shift schedule is also being re-examined. Draft policies with respect to the maximum number of continuous days of work and the maximum number of hours per shift are being prepared. The company is now extending its program beyond shift workers to anyone likely affected by long hours, compressed work weeks and frequent travel.

"Fatigue countermeasures" is an awfully fancy title for the changes CN and NOVA are implementing. Many outside the field might simply label them common sense. Michael Darby doesn't care. CN normally runs a million track miles without incident, good enough to earn it third place among rail lines in its class in North America. It's now up to two million, and second place. Top spot is within reach.

The program embarked upon by NOVA, the rail industry, and many others is often frustrating, always time-consuming. It's still largely an act of faith. There are no hard numbers to convince the doubters. The basket of evidence against shiftwork is stocked largely with anecdotes, personal experience and common sense. Who among us hasn't found his or her mind drifting, eyes growing heavy, on a quiet country road in the middle of the night? Should a society deeply concerned about tired truck drivers on busy highways be any less concerned about tired technicians in nuclear plants or chemical factories?

Michael Darby will boast about CN's two million incident-free miles. Wendy Joel will talk about the 19 workers diagnosed with sleep disorders under NOVA's new program, all successfully treated, or about the two workers formerly on short-term disability, now back at work.

"Debt" is a metaphor favoured by sleep researchers. Deprive yourself of the sleep you need, and you will build up a sleep debt. That debt must eventually be paid, possibly through compromises to health or social well-being, possibly through a decline in productivity or quality. It can also be paid through a lapse of attention, or by spontaneously falling asleep. "If that happens on the job, there's potential for tragedy," warns Ron Hesslegrave.

When that happens on the job, it can be a debt paid with heavy interest. It's a debt that may have been paid in Chernobyl, Ukraine, or Bhopal, India, or Prince William Sound, Alaska, or at a trackside 16 kilometres east of Hinton, where a small stone cairn with a brass plaque reads, simply, "8 Feb. 1986".

MAKING SHIFT WORK WORK

Educating the work force may be the toughest nut an employer has to crack. NOVA's Shiftwork Awareness Program was mandatory at first, and that gave rise to resistance even though training was held on company time. Faye Ackermans, general manager of safety and regulatory affairs for CP Rail, reluctantly concedes that there's a "testosterone factor" common among many shift workers, although she feels the tide is turning. NOVA's solution, says Wendy Joel, was to train shift workers to run the programs themselves. "It's not a case of someone who's never worked a shift getting up and telling them what's good for them," she says.

• Fixed overnight shifts won't solve all the problems associated with shiftwork, but experts seem to agree they are better than rotating overnights. "If you've got people who really want to work nights and adapt well to working nights, why don't you let them work steady nights?" asks Jon Shearer.

• If you run rotating shifts, try to avoid short rotations. It takes roughly two weeks for a body to adjust to a new sleep-wake cycle. Workers who rotate once a week never get a chance to adjust.

• Rotate clockwise. If the shiftwork schedule has to rotate at all, make sure that workers changing to a new shift will be starting it later in the day, rather than earlier. If the "day shift" is eight a.m. to four p.m., rotate those workers forward onto the four-to-midnight shift, not backward onto the midnight-to-eight shift. People adapt more easily to staying up later -- and they will be tired enough at the end of the shift to be able to sleep.

• Communicate. Publish a shiftwork newsletter. Set up a shiftwork bulletin board. Provide training and information sessions. There's an awful lot of bad information about shiftwork and sleep, says Jon Shearer. Make certain your workers can distinguish fact from theory, and theory from myth.

• Don't ignore the families. Include children and spouses in your education program. "When you schedule somebody, you schedule everyone that rotates around them," says Jon Shearer.

• Make certain your company's service departments accommodate all shift workers. Do all shift workers have the same access to cafeteria services? Health services? Personnel? "Most places that have shiftwork manage the damned place as if there's only one shift," he says.

• The human body responds to light. Keep the workplace brightly lit at night.

• Know your work force and design a schedule that is reflective of its unique characteristics. With the help of a shiftwork expert, you can devise a work schedule that makes best use of your work force’s strengths.

• Treat each work site as a unique workplace, with its own scheduling needs. A schedule for a plant where workers face a one-hour commute will not be the same as one where most of the work force lives close by.

• The minimum period you should permit between shifts is 12 hours, says Ron Hesslegrave, and only if there is a good opportunity for sleep in the interval. Cathy Walker of the Canadian Auto Workers may describe the lengthening of the work day as "a terrible trend" in the workplace, but its something both workers and employers seem to want. Employers say absenteeism drops and productivity increases. Workers like the extra days off.

• Consider opportunities for "planned napping" on your overnight shift. A short nap can have a temporary rejuvenating effect. Too long a nap can lead to the opposite. Recognize that some people nap better than others.

• Allow for frequent breaks.

• Don't trust your workers to know when they're too tired, warns Alistair MacLean, a professor of psychology at Queen’s University. An exhausted worker may boldly proclaim "I'm fine" one moment and be fast asleep the next.

• Constant vigilance jobs can combine sleep debt with crushing boredom -- possibly a deadly combination. The challenge is to make the workplace more stimulating without making it distracting. Frequent changes in activity can prevent boredom. Interspersing active tasks with sedentary ones can also help.

• If possible, schedule high-risk jobs for day or evening shifts.

• Try to schedule non-critical equipment checks or procedural tests into the overnight shift.

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YOU SNOOZE, YOU WIN

If you are a shift worker, your sleep is not wasted time. It must be made a priority. Don't be lured by the opportunities offered by the day. Your sleep is more important than shopping, or cutting the grass, or shoveling the walk.

• Develop a sleep ritual. Go through the same "winding down" activities every day before retiring. Hit the mattress every day at the same time, and educate those around you to support and respect your schedule and your need for sleep.

• Sleep in the quietest room in the home. If daytime noise is a distraction that prevents you from falling asleep, try using earplugs.

• Some researchers suggest that you try to schedule your sleep period closest to your work time. Day workers head to work shortly after rising. Night workers should try to do the same. Whether you choose to sleep in the morning or the evening, if you find a sleep-wake routine that works, stick to it. A good routine is one that allows you at least six hours of continuous, uninterrupted sleep.

• Understand how light acts as a trigger for wakefulness. If you are a morning sleeper, try to avoid sunlight on your way home. If you can leave work before sunrise, do so. If you can't, consider wearing dark glasses for the ride home. Once you get home, head straight to bed, without turning on the lights. Keep your bedroom as dark as possible.

• Avoid strenuous exercise in the hours immediately before sleep. Exercise is good, but if you take a long walk, an aerobic workout or a three-mile run every day, schedule it for just before work or just after work -- not in the three or four hours before sleep.

• People carry their waking concerns with them when they try to sleep. If this is a problem for you, set aside a time of day as your "worry period". Use that time to work out the issues that are giving you concern. Clear your mind of worries and frustrations as you settle down to sleep.

• A room that is too hot, or too cold, will not help you sleep. Experiment. Find the sleeping temperature you like best.

• Make certain your environment is conducive to sleep. If there is a phone in your room, unplug it. Don't answer the door. Make certain family and friends understand that you are unavailable during your sleeping hours.

• Take some of that premium you're earning on your overnight shift, and invest it in a top-quality mattress.

• Night workers should recognize that they are at their most vulnerable if they drive during the commute home. Use public transit. If you must drive, try car-pooling. Roll down the window. Turn on the radio. Sing.

• Try to schedule an "afternoon" nap for the middle of your waking day. Core body temperature drops at this time. What people refer to as the "post-lunch dip" is really a cry from your body for some shut-eye. Heed its call.

• Try to stay on your shift schedule for the complete rotation. Switching to the "normal" cycle on Saturday and back to the shift schedule on Monday will prevent your body from ever adjusting properly.

• Be aware of signs of trouble. Shift workers begin manifesting problems in their mid-thirties, says Ron Hesslegrave. What you call "tossing and turning" is what the experts call "fragmented sleep", and it means you're not getting the sleep you need.

• When being prescribed medication, make certain your doctor knows you work shifts. Irregular sleeping and eating habits can interfere with some medications. Others induce drowsiness. Diuretics can interfere with your sleep. Diabetics should carefully discuss their daily routine with their physicians and dietitians.

• Avoid alcohol and over-the-counter medications.

• Avoid caffeine, especially during the later stages of your waking day. While your experience may be that caffeine doesn’t keep you awake, it doesn’t help you sleep either. That caffeine keeps you awake at work is not really true. It keeps you keyed up and it interferes with your ability to fall completely asleep; but it won’t clear your mind or keep you from "micro-sleeping" on the job. Often, the boost that we get from a caffeinated beverage actually comes from the sugar it contains. Have a muffin and a fruit juice, instead.

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EAT RIGHT, SLEEP TIGHT

One of the biggest concerns reported by shift workers is digestive problems and a constant feeling of nausea. Part of the problem may be that the sleeping cycle is out of synch with the eating cycle. When you work shifts, make sure that your eating times rotate on the same schedule. This may be difficult if those around you are on a different schedule; mealtimes are, after all, the focus of social and family interaction. But to successfully adapt to a shiftwork schedule, you will have to discipline yourself -- and educate those around you -- to the needs of shiftwork.

• If you are a person who normally eats breakfast within an hour of awakening, continue to do so regardless of the time of day you actually awaken. Eat what you would normally eat for breakfast -- even if those around you are having lunch or supper.

• Eat your major meal of the day in the middle of your waking period -- again, regardless of the time on the clock. (Eating a big, meat-and-potatoes meal just before going to bed would tend to keep you awake.)

• Eat a light, carbohydrate-rich meal near the end of your waking period. Cold or hot cereal is a good choice. Toast and jam, with milk or juice, is another.

• Schedule your snack breaks at work to stay in synch: Take a break and a bran muffin one-and-a-half to two hours after starting work; have another in the middle of the second half of your shift.

• Eat a fibre-rich diet. Jon Shearer explains that sufficient fibre is a key factor in maintaining good digestion, which takes on added importance when the system is also stressed by shiftwork. And good digestion helps you sleep.

• Stick to your adjusted eating schedule even if you are tempted to join those around you for meals, snacks and extra coffee breaks; remember, they’re running on a different schedule than you are.

• Especially on night and evening shifts, avoid falling into the trap of eating or drinking coffee out of boredom. If you need a break, take a walk.

• As with your sleep-wake cycle, make an effort to keep your eating cycles regular. Don’t fall into the trap of skipping a meal because of nausea, then snacking excessively as hunger returns, missing the next meal because of lack of hunger, and so on.

• Drink warm milk before retiring. It has been shown to help many people drift off to sleep.

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