What you don’t know about lighting can hurt you.

Global warming may still be up for debate. But there’s no question that the world’s getting brighter—due to the proliferation of both indoor and outdoor lights.

“Darkness is as essential to our biological welfare, to our internal clockwork, as light itself,” writes Verlyn Klinkenborg in a recent National Geographic article. Sleep scientists find that bathing our world in artificial light not only disrupts our body clocks but also disturbs hormone production.

One recent study links higher rates of breast cancer in women with night-time brightness in their neighborhoods. And numerous studies find an increased risk for cancers—prostate as well as breast—among night-shift workers. Experimental evidence suggests that the antioxidant hormone melatonin, critical for sound sleep and healthy immunity, plays a major role in increased cancer risk.

One interesting investigation published in Medical Hypotheses suggests that artificial—versus natural—light not only inhibits melatonin production but also increases the circulating estrogen levels, increasing the risk for melanoma. French researchers note the therapeutic effect of melatonin in metastatic diseases, and seasonal patterns in melanoma are consistent with seasonal melatonin production in the body.

A 2009 New York Academy of Sciences conference paper implicated artificial lighting in cancer, depression, diabetes, and obesity. And certain types of fluorescent lighting can be particularly damaging.

In addition to health problems—ranging from headaches and eye problems to electromagnetic radiation—linked to fluorescent lighting, a new study at the University of Pennsylvania finds that long-term exposure can cause cumulative skin damage in people with lupus and other photosensitive skin disorders. Those new energy-efficient compact bulbs add even another risk—the potential for mercury pollution.

Dr. Ann Louise’s Take:

Light pollution may be the easiest environmental hazard to remedy. But it’s all too easily overlooked in today’s 24/7 world where people text into the wee hours and when global climate change seems a far more pressing issue.

I’ve been concerned about light pollution for some time now. The typical American gets only about 7 to 8 hours of darkness every night—and probably only secretes melatonin 6 to 7 of those hours. Without today’s light pollution, though, we’d be producing this critical hormone for 9 to 10 hours a night!

Most indoor lighting ranges from 100 to 1,000 lux (a measurement of how light illuminates). Studies show that as little as 100 lux at night can inhibit melatonin production—and 500 lux (easily achieved in our brightly lighted homes and urban centers) can impair melatonin production up to 98%.

The Right Light
Then there are specific risk factors depending on the type of artificial light you’re exposed to. For example, energy efficient fluorescents—whether those long tubes or the compact fluorescent lights (CFL)—create elevated magnetic and electric fields whenever they’re on.

Research at University of Oklahoma College of Medicine also finds that compact fluorescent bulbs—unless they come with shields—leak ultraviolet B radiation, which is key in promoting skin cancer. Is this the lighting you want next to your—or your child’s—head?

Break one of these corkscrew-shaped CFLs—and you’ve got a Hazmat crisis right in your own home! That’s because the mercury in just one bulb can contaminate a whole room. Recycling them isn’t easy, either. In a landfill near your home, they leach mercury in groundwater and soil.

In addition to fluorescents, halogen lights (which generate a lot of heat and require ventilation) and even the electrical wiring in your home can produce significant amounts of electromagnetic fields (EMFs), increasingly found hazardous to human health. A low voltage DC halogen light that’s set into the ceiling is safe if you’re beneath it, but it can radiate high magnetic fields about three feet into the floor above, so don’t place them underneath rooms where children sleep or play. In addition, the AC magnetic fields produced by lights and ceiling fans are greater in the rooms above them because you are closer to the source.

For safety’s sake, the classic incandescent bulb and LEDs are best. There’s a new generation of these lights coming to market that meets the tough 2012 efficiency standards, and Philips makes an energy-efficient incandescent bulb (really a halogen lamp in incandescent clothing) that’s already available at Home Depot and on Amazon.

Up Your Melatonin
This hormone enhances the power of the immune system’s lymphocytes to fight cancer cells that slip by the body’s other defenses, so it’s hardly surprising that low melatonin levels have been implicated in breast cancer, melanoma, and malignancies of the ovary and prostate. Low levels of melatonin are also linked in Alzheimer’s and Parkinson’s diseases.

Even low levels of EMFs can depress melatonin production, so I advise trying some of the detection devices I’ve found useful in my own home. Go to www.annlouise.com/65/emf-product-guide/ for handy, reasonably priced ways to discover—and if necessary, re-mediate—dangerous radiation in your home or office.

Room-darkening drapes and shades won’t reduce your exposure to electrical and magnetic field radiation. But keeping your room darker longer can help your body produce more melatonin, which is also diminished by exposure to EMFs.

In studies of older people (who tend to have lower than normal levels of melatonin and consequently have trouble sleeping), those who were exposed to about two hours of sunlight a day had higher levels of melatonin—and slept better—than those who didn’t spend as much time in the sun. Even being outside on a cloudy day or sitting in the shade appears useful.

Blue light helps keep you alert, but it also suppresses melatonin production in the evening. Researchers with the Lighting Innovations Institute at John Carroll University in Ohio have developed reasonably priced blue-blocking glasses, light bulbs, and night lights that their studies found helped promote better sleep and reduced symptoms of ADHD in people who wore them a few hours before bedtime (see resources).

LowBlueLights.com has special glasses and nightlights that block out blue light that inhibits melatonin production. I own a pair of these glasses and wear them an hour before bed, which helps me sleep through the night without waking.

Because melatonin regulates the sleep-wake cycle and supports other antioxidants as well as vital immune system components called natural killer cells, also consider melatonin supplements (1 to 3 mg in a time-release formula). Tart red cherries are an excellent food source of this antioxidant hormone.

Added Support
In one placebo-controlled study, Jeffrey Cram, PhD, tested the effects of a specific flower essences—Yarrow Special Formula and Five-Flower Formula—on people exposed to fluorescent lights. While the placebo group exhibited increased agitation from these artificial light frequencies —those subjects who took one or the other of the flower essences did not!

Sources:
How to Stay Young and Healthy in a Toxic World
http://jcem.endojournals.org/cgi/content/abstract/90/5/2755
http://lrt.sagepub.com/content/21/1/11.short
www.ehso.com/fluorescent_safety.php
http://www.ncbi.nlm.nih.gov/pubmed/20640236
http://www.ncbi.nlm.nih.gov/pubmed/20347530
http://www.ncbi.nlm.nih.gov/pubmed/20015100
http://www.ncbi.nlm.nih.gov/pubmed/19395458
http://www.ncbi.nlm.nih.gov/pubmed/19320850
www.npr.org/templates/story/story.php?storyId=7431198