BWC ergonomist addresses Kentucky Trucking Association Nov. 15
By Delia Treaster, PhD, CPE, BWC Ergonomic Consultant
Drowsy driving kills.
In 2013, it caused 72,000 crashes on our nation’s highways, killing at least 800 drivers and passengers and injuring another 44,000, according to the National Highway Traffic Safety Administration. Some feel the true number of fatalities is actually closer to 6,000 deaths per year.
Drowsy driving is of particular concern to the trucking industry, and that’s why I presented “Shift Work, Circadian Rhythms, and Sleep” to the Ohio Trucking Association in January this year. Some members from the Kentucky Trucking Association were in the audience and invited me to give the same presentation to their association. So with BWC approval, I packed up my PowerPoint and traveled to Louisville on Tuesday, Nov. 15.
The major points I shared with the association can apply to the rest of us, as well. The bottom line is this: Proper and sufficient sleep is critical to the quality of our lives at home and at work. Sleep deprivation impedes our work performance and threatens our health and safety. It can even cause brain damage. (More on that later.)
For truck drivers, it’s especially difficult to get a full and restful night of sleep. Irregular driving hours (often dictated by delivery schedules), lack of sufficient truck stops en route, and hours-of-service rules that don’t align with real world demands are some of the factors that can disrupt circadian rhythms and interfere with sleep. (Circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment.)
Compounding the problem of sleep loss are electronic devices that emit blue light, such as laptops, tablets and smart phones. The wavelength of blue light has a strong inhibitory effect on the production of melatonin, the sleep hormone. Too much blue light at night and the amount of melatonin secreted in the brain drops dramatically. This leads to either poor sleep (with lots of night-time waking) or a delay in the sleep cycle, causing you to fall asleep later. Either way, it results in less sleep.
If you’re sufficiently sleep deprived, you will fall asleep, whether it’s the middle of the day or the middle of the night. This is because your brain simply shuts off, no matter the situation. It might be just an instance of “microsleep,” a very short sleep episode lasting one to 30 seconds. Now imagine what that instance of microsleep can cause when you’re behind the wheel of a 40-ton 18-wheeler, or even a Subaru, for that matter, traveling at 70 mph.
People don’t know when they microsleep – indeed, you can microsleep with your eyes open! And you have no control over it. Just know that no amount of willpower, motivation, or training can overcome the effects of sleep deprivation.
Now, about that brain damage. Long term effects of chronic sleep loss can cause permanent brain damage. It turns out that sleep is essential for some basic brain housekeeping. Neurotoxins are removed during sleep – and only during sleep. Sleep loss means those neurotoxins accumulate in the brain, and that leads to neuron loss. Research has shown that sleep loss causes permanent and irreversible brain damage in mice.
Truck drivers aside, many people who work non-traditional hours (outside the hours of 6 a.m. to 6 p.m.) face serious disruptions to their circadian rhythms, making it hard to get a good night’s sleep. So protect your health, your brain, and stay safe on the roads by getting enough sleep! That’s seven to eight hours for most people every night. Also, be sure to avoid caffeine and electronic devices late at night.
One or two nights of insufficient sleep aren’t too bad – we’ve all been there – but don’t make a habit of it. Just be sure to make up your “sleep debt” as soon as possible.
Delia Treaster joined BWC’s Division of Safety and Hygiene in November 2013. She holds a master’s degree in human factors engineering and a Ph.D. in occupational biomechanics.