As summer wanes, we may be acutely aware that the days are growing shorter. But our indoor lifestyle, scientists now say, effectively keeps us living in the dark ages year around.
Our cars, homes, factories, offices and shopping malls are, it seems, casting a perpetual pall over our very existence. While direct sunshine may be detrimental, biomedical researchers, psychiatrists and psychologists say our lack of exposure to adequate amounts of daylight is hazardous to our physical and emotional health.
It wasn't always this way, of course. For millions of years, our hunting, foraging and agrarian ancestors lived and worked outside. Less than a century and a half ago, however, that way of life began to change. The Industrial Revolution took us out of the fields and into the factories. The information age took us into offices and deeper into the shadows. Natural light, the kind of light that millions and millions of years of evolution had constructed us to respond to, was replaced by artificial electric light, an inadequate substitute, as it turns out.
Recent research has begun to confirm what many of us have known all along -- if only subconsciously: Too little daylight has a detrimental effect on our physical condition and our emotional outlook. Daylight is what keeps our body clocks ticking. It tells us what time to get up, what time to go to bed (signals now largely ignored because of the electric lights), and is largely responsible for how we feel emotionally. But the effects of daylight on humans, the experts say, go way beyond spring fever and winter blahs.
Daylight influences our body temperature, blood pressure, and the release of certain chemicals by the nervous system that determine how alert or how tired we are at different times of the day and year. Conversely, daylight deprivation can result in or contribute to bouts of depression (ranging from mild to manic), loss of appetite, insomnia, fatigue, anxiety, lethargy, immune system dysfunction, hormone production, perhaps even premenstrual syndrome and infertility.
Scientists studying the problem say many of us simply aren't getting our minimum daily requirement of daylight. Recent surveys indicate that many adults get less than an hour or two a day of exposure to natural light.
In fact, the National Institute of Mental Health says that as many as 12 million Americans suffer from SAD -- Seasonal Affective Disorder -- the most extreme form of a seasonal syndrome attributed to light deprivation. (For those diagnosed with SAD, doctors may prescribe a daily regimen of sitting in front of a metal box containing full-spectrum fluorescent lights that approximate the qualities of natural daylight.) Another 35 million -- most of whom live in the country's middle and northern latitudes -- experience some seasonal distress that affects their moods and behaviors.
Because of these findings, pioneering architects and building-products manufacturers such as Andersen Windows and 3M, which produces window films and coatings, are busy devising ways to bring more natural light into buildings that house large numbers of people. So far, their work is pretty much limited to new high-rise office buildings and large chain stores, but the concept, called, appropriately enough, daylighting, will likely be applied in the near future to buildings of all kinds -- schools, hospitals, libraries, institutions, government buildings and multifamily housing.
The daylighting movement is producing large commercial buildings that will rely more on free and abundant natural light and less on costly electric light. New kinds of skylights will focus and project light deep into interior spaces. New window films will filter out solar heat but allow daylight in. Window size and placement will be planned to make the most of daylight. All this is being done to reduce on-the-job physical and emotional stress and to save energy.
Eventually, daylighting principles will be applied to new single-family homes as well. The issue may be less critical for houses because most houses have windows in every room.
But part of the daylighting concept has to do with the quality and duration of natural light, not just the quantity. Generally, the objective should be to bring daylight -- not direct sunlight -- into a home from high up via skylights, roof windows and glass transoms over doors and windows so that it illuminates interior spaces and bounces off light-reflective surfaces, extending the occupants' exposure to natural light for as long as possible.
Fortunately, home owners won't be required to invest in high-tech building products to maximize the light-absorbing potential of their homes. Most of what's required is already on the market. Large windows, skylights, transoms, French doors and sliding glass doors can all help to dispel the daytime gloom. Bay windows can bring light in from three sides. Sun rooms, atriums and greenhouse additions can allow occupants to bask in daylight. Open floor plans allow light to flow unobstructed from the exterior to the interior. Using light colors for walls, floors and furniture can also help to lighten and brighten rooms. Simply trimming the trees in the yard and the shrubbery around windows can help bring more light inside.
Energy-efficient solar windows and window films can eliminate solar heat gain and the fading of upholstery fabrics. Venetian blinds are excellent for controlling the intensity and direction of daylight.
The bottom line here is that if it makes sense to "daylight" the large buildings in which we work and shop for health and energy-conservation reasons, it makes sense to do the same thing at home. After all, if you subtract the eight hours you spend at work (during the day for most of us) and the eight hours you
spend asleep from the 24-hour day, only eight hours are left. And most of that is spent in the house. Daylighting strategies won't keep the sun from setting or cause it to rise earlier, but it can help to increase our exposure to daylight during the hours we spend at home.
And if the concept means less reliance on costly electricity, less dependence on fossil fuels to generate electricity and less pollution from power plants, not to mention a more natural and healthy lifestyle, all the better. If nothing else, the daylighting movement reminds us, once again, that it's not nice to fool Mother Nature and that our bodies and our homes are intimately tied to the natural environment.