Studies have shown that lighting levels have a major impact on the levels of human health, happiness and safety. Light pollution can be defined as more than necessary, misdirected and intrusive artificial light. Some of these artificial light sources emit blue light or ultraviolet radiation which is particularly bad for human health. Experiencing this kind of light exposure has a horde of negative effects on one’s health. Our bodies require a certain amount of natural light each day to sustain necessary circadian rhythms, vitamins and hormone levels. And yet many of us are outside less than 30 minutes each day. We are exposed to light pollution at times of the day when we should be sleeping, resting or experiencing dimmer light. Without appropriate light levels, humans may experience a horde of negative effects on one’s health.
The timing, duration, color, intensity and wavelength of light has serious impacts on human circadian rhythms, which are the physical and psychological changes humans experience each day. Circadian rhythms are important to human health because they influence sleep cycles, hormone release, body temperature and emotional temperament. This means that when one is exposed to light at times when one should be resting, sleeping or relaxing, it may cause a decline in productivity, general malaise and depression. Furthermore, experiments have shown that when mice are exposed to artificial light at different points throughout the day, it substantially decreases their metabolism. Scientists observed that mice kept in 20-hour light/dark cycles for 10 weeks gained more weight than mice that experienced normal 24-hour daytime and nighttime light levels.
It is well known that at nighttime, light levels on roads and streets have the greatest impact on a driver's ability to see where they are going. Without appropriate levels and lighting fixtures, there are more accidents and tragedies on highways and backroads. In fact, the NZTA Economic Evaluation Manual shows a 35% decrease in crashes when communities upgrade or improve their road and street lights.
Melatonin is a hormone produced by the body’s pineal gland. It is secreted at nighttime to regulate a person's biological clock. When this gland thrown off, studies show an increase in different types of cancers. Breast cancer specifically is shown to be more prevalent in those who have sleep cycles impacted by artificial light levels.
In a study done by the Cancer Research center in 2005, female volunteers were broken up into groups and exposed to three different types of lighting conditions. Those who were exposed to artificial light during the night for 90 minutes revealed showed melatonin-deficient blood cells. When these cells were injected into tumors, the cells with melatonin-deficient blood grew rapidly compared to those tumors that had sufficient melatonin.
To avoid the negative impacts associated with light pollution, be sure to choose appropriate light levels and fixtures for each application, whether that be a sign, site or street. Solar and LED technology work to reduce light pollution by directing light towards a specific area rather than shedding lights in regions that do not need to be lit. Furthermore, LED fixtures do not contain damaging blue or ultraviolet light. Check out Ember LED’s blog post, “How Much Light Do You Really Need?,” to learn more about the appropriate light required for specific applications.