Over Illumination

Our job is a stressfull.  When we are not on the road and actually have a moment to rest and regenerate back at our station what can be done to make sure we are healthy and rested?  Does your station have high powered flourescent lights?  Can these lights be turned off or are they hardwired to stay on always?

As summer turns to autumn and the days grow shorter, you may think there’s no such thing as too much light. But if you’ve ever come home from the office or the shopping mall feeling fatigued and headachy, you’ve probably already experienced some of the symptoms of over-illumination.

Over-illumination occurs when there’s too much light (or the wrong type of light) present for a specific activity. It’s common in public buildings constructed before 1995. Besides wasting energy, over-illumination is thought to cause headaches, fatigue, stress, increased risk of certain carcinomas, and high blood pressure.

The culprit for many is overhead fluorescent lighting.
According to the book Human Factors in Lighting, fluorescent light is poorly matched to the spectrum of sunlight, which the body expects and which is used to set our circadian rhythms. Our bodies translate overexposure to fluorescent light as “total darkness” and then reset our circadian clocks incorrectly. This results in fatigue and also may suppress the immune system, thereby increasing the risk of cancers.

Fluorescent light also causes problems when it flickers. Environment, Health and Safety Online describes light flicker as “quick, repeated changes in light intensity—light that appears to flutter and be unsteady. It is caused when the voltage supplied to a light source changes or when the power line voltage itself fluctuates.”

The Canadian Centre for Occupational Health and Safety points out that “flicker is usually a potential problem only with lighting that requires the use of ballasts, like fluorescent lights.” (Ballasts control the electrical supply to fluorescent lights.) Incandescent lights usually do not flicker since the light filaments generally do not cool quickly enough (and make the light dimmer) as the voltage changes in the AC power line.

Some studies have shown that the flicker and over-illumination combined yield a particularly high incidence of fatigue.

But, as fluorescent light is energy efficient and generates a lot of light without using a lot of electricity, it is found in most public places. So what can you do?

Well, if you’re out shopping, you can seek out newer malls that utilize “daylighting” (basically, skylights and other methods of letting in natural light). You can limit your shopping time, or take breaks outdoors. You can also urge mall owners to retrofit lighting fixtures to minimize this form of “light pollution.”

On the job, you can talk the maintenance crew to make sure they are regularly monitoring the lighting system. They should replace fluorescent tubes when ends begin to blacken, and they should clean fittings often.

Bulbs should be replaced on a scheduled basis, as old bulbs tend to flicker more and are not as bright. They should ensure that all parts of the light fixture, especially the ballast, are functioning properly. You can recommend that when replacements are needed, they upgrade to fluorescent lighting that uses electronic ballasts.

In some cases, you may even be able to turn off/disconnect the overhead light and rely on task lighting at your desk. If you do so, place your task lighting on the opposite side of your writing hand to prevent shadows on your work, and make sure your light does not cause glare on your computer screen.