Safety Article by Harold Hough

Many mines run 24/7 in order to maximize productivity. With good maintenance practices, a multi-million dollar piece of equipment can be run around the clock, and provide three times the ore delivered to the mill for just the cost of the additional fuel, maintenance, and operators.

The problem is that people aren’t designed for 24/7 operations and many managers don’t realize the risks of around-the-clock operations. Most workers can’t be plugged into a 24 hour work schedule without considerable safety, health, and productivity risk.

How bad can the safety problem be with sleepiness? According to post accident reports, sleepiness was partially responsible for the nuclear problems and both Three Mile Island and Chernobyl. The oil spill caused by the Exxon Valdez in 1989 was also blamed partially on sleepiness.

Mine managers may not want to admit it, but the human is a daytime creature. Our bodies are designed to function in tune with the circadian cycle - the 24 hour pattern of day and night. Our bodies want to be awake during the day and they want to sleep at night. When we try to change that cycle the body undergoes many physiological changes that affects everything from attentiveness to a less effective immune system.

The fact is that a worker on a night shift, who didn’t get a good sleep before coming to work, is just as dangerous as if he were legally intoxicated. A night shift worker with poor daytime sleep habits may be awake for more than 18 hours by the end of his shift. The effects of acute sleep deprivation can be compared to impairment due to alcohol intoxication, with 19 hours of wakefulness corresponding to a Blood Alcohol Content (BAC) of 0.05%, and 24 hours of wakefulness corresponding to a BAC of 0.10%.

Studies are also discovering that sleep deprivation can lead to medical problems. The International Agency for Research on Cancer has classified “shift work that involves circadian disruption” as a probable human carcinogen. Sleepiness has also been shown to lower the body’s immune defenses, help contribute to diabetes, obesity, gastrointestinal disorders, and heart disease.

Lack of sleep is not just a safety and health issue. Studies show night workers often have productivity levels 25% to 40% lower than day workers.

Mines can’t change human physiology, but they can encourage practices that will make their shift workers more productive and safe.

AVOID ROTATING SHIFTS. Some mines think that rotating shifts is a way of being fair and forcing everyone to “suffer a bit.” The problem is that rotating sifts is even worse because it never allows the body to adjust to one sleep cycle. In fact, researchers think that it takes the body up to three years to adjust to a new sleep cycle, which means rotating shifts create a situation where all three of your shifts are working with sleep deprivation problems, instead on only one or two shifts. A study by Harvard Medical School showed people who have rotating shifts are more susceptible to hypertension and cardiovascular disease.

DEVELOP BEDTIME HABITS. When you turn off a computer, you don’t just pull the plug. You go through an established shut down pattern. The same is equally true with humans. The body recognizes patterns that you may use before going to sleep; listening to music, reading a book, having a snack, taking a shower, or having a cup of tea. This puts your body into a “shutdown” mode even before going to bed and makes it that much easier to go to sleep.

If you work irregular hours, try developing some bedtime habits that work with your lifestyle. That will give your body a signal that it’s time to go to sleep, even if everyone else is awake.

A GOOD SLEEPING ENVIRONMENT. Where you sleep is just as important as anything else. Obviously the darker the room, the better because the body recognizes darkness as a sign that it is time to sleep. However, even small amounts of light can destroy that. If your drapes aren’t cutting out enough light, consider getting heavier drapes, an eye mask, or putting something over the windows when you sleep.

Noise is also a problem, especially if you are trying to sleep while everyone else in the house is awake. Obviously, getting family members to be as quiet as possible during your sleep is important. However, as there are bound to be noises you can’t silence, experts recommend some sort of “white noise” that will mask these other noises. Although there are white noise generators available, a fan, air filter, or air conditioner can also do the job.

Fans and air conditioners may help with the third environmental factor; temperature and ventilation. A good sleeping environment is cool (65 – 68 degrees) and well ventilated. Sleeping with a blanket also helps.

FOODS THAT CAN HELP YOU SLEEP. As mentioned earlier, a light snack or cup of tea can become part of your bedtime habits. And, some drinks can actually help you become sleepy. Warm milk is a traditional sleep aid. And, for those who aren’t into warm milk, there are several types of decaffeinated herbal teas that can help.

Conversely, stay away from caffeine and alcohol. Even though alcohol makes you drowsy, the problem is that it does not produce the normal sleep patterns that produce the best results. The same thing applies to sleeping pills.

These recommendations should help you sleep better during the day. However, keep in mind that since daytime sleep is out of sync with our body’s biological clock and is more likely to be disturbed, there will probably be less deep sleep and REM cycles that make sleep more restorative. The result is that you may still be tired and you may start to develop a sleep deficit. If that happens, a couple of good sleep cycles during your weekend (whenever that it) can help considerably.