In Orion Interiors Inc. our main concern is to provide our clients all the needed information in order for them to make a smart purchase that will not only enhance the look of their interior but also will help them with maintaining a healthy environment. In the following article we will try to explain the effects of different light sources on human body and how to create the right lighting environment. Please do not hesitate to contact our lighting store in Toronto in case you have any additional questions.
Studies of biological non-visual effects of light on the human body have shown great impact on human health.
Research has revealed that at the same level of operation and distribution of light sources, the effectiveness of their impact on the human body depends mostly on the proportion of the blue component of the emission spectrum of the light source.
Non-visual biological effect of light is the effect of light sources on the production of the hormone melatonin and its obstruction. This hormone is necessary for not only normal operation of our biological clock, but also has antioxidant and anticancer properties. This effect was discovered by scientists only recently – in 2002. Open type of photoreceptors in the eye has nerve connection with the brain by the pineal gland (epiphysis), which regulates the production of melatonin. This system adjusts the internal biological rhythms for the outside world.
Peak sensitivity of these receptors is in the wavelength range of 440-500 nm (the blue color). Thus, cool white light, which has greater proportion of blue, stimulates stronger biological effect than light with a higher proportion of red (warm white). Under natural conditions melatonin is released at night – from 21 to 7 hours. Peak production usually occurs at 2-4am. However, the melatonin production is suppressed by any light that is in the blue range.
LED lamps, are based on blue diodes with peak wavelength at 450 nm. In this type of illumination, melatonin production is reduced 5-fold compared to the yellow light of the filament lamp in which blue is almost completely absent. Halogen lamps reduce melatonin production by three times. In this connection, for each area in the house it is necessary to consider light sources that emit different colour/temperature of light. It turns out that LED lamps with warm color temperature (2700-300K), where the proportion of blue emission is low, is best suited for evening or night lighting – it is proven that their biological effect is the same or even less than that of incandescent lamps. LED bulb that has neutral and close to the cold light (4000-5000 K), has a higher biological effect, so it is wiser to use it in the morning and early evening.
In addition to the visible light in the range of 400-700 nm, any light source releases collateral radiation. It does not add to the lighting strength but may adversely affect the human body. This include infra-red (IR) radiation, ultraviolet (UV) rays, and electromagnetic radiation (EMR) of different ranges. Different light sources have different levels of radiation emissions.
Incandescent lamps, for instance, produce a vast amount of infrared rays and a small amount of UV while EMR is completely absent due to lack of electronic components inside.
In halogen lamps, especially low-voltage, there are high levels of UV radiation. Therefore, without filter aids in the quartz bulbs and UV filters, halogen lamp can ruin the interior items that are illuminated by it. Also, UV radiation is harmful to human health: it can provokes skin and eye diseases.
Energy-saving (CFL) lamps are characterized as moderate level of IR radiation, noticeable level of UV radiation, and problematic with EMR. Phosphor is used in energy-saving lamps in order to convert UV radiation into a visible light. However, unfortunately not 100% is converted and some of UV radiation is still released to the outside. The more the layer of phosphor will degrade and reduce, the more percentage of UV-radiation will increase. Under normal circumstances, it is not a problem, however, when the luminaires are close to the person, the intensity of the rays is equal to solar. Energy-saving lamps also tend to emit EMR, which comes from a start-up control apparatus. People who are particularly sensitive to this kind of radiation, near the lamps may experience lethargy, headache and other unpleasant sensations. More attention should be given to the sources of EMR in your home.
Unlike all previously mentioned light sources, LED lamp is the purest light source. It has no UV and IR radiation, and EMR have minor figures, since the lamps have small capacities, and the lamp housing partially shields these radiations. The only significant collateral emission that can be attributed to this type is the high level of the blue spectrum in these lamps. And, this level is increased when the coating layer of phosphor on the LED chips degrade. However, this degradation is too slow, due to the technical characteristics of the lamps. Therefore, while adhering to the proper distribution of light by the light colors/temperatures LED lamp can be a reliable and absolutely safe creator of comfort in your home.