Human understanding of light starts from the sun, the visual function of the human eye can only distinguish the light and dark of the visible part of the sun, the vision of the human eye can not identify the part of the sunlight that is harmful to human health, the method of analysis of light is spectral analysis, through the spectral analysis of sunlight, you can understand what wavelength of light sunlight is composed of, what is the proportion of light of each wavelength, and what components of sunlight contain that are beneficial or harmful to human health.

Spectral analysis is the basic means of all light source analysis, because the physical properties of artificial light sources are the same as those of sunlight, but the spectral shape is different, by analyzing the spectrum of artificial light sources, we can also analyze the health effects of different artificial light sources.

To study the impact of sunlight on human health, we are analyzing the sunlight that reaches the ground, some of the sun's light is absorbed by the earth's atmosphere and cannot reach the ground, and the wavelength range of sunlight that can reach the ground is 250nm to 2500nm, as shown in the figure below.

According to the full spectrum of sunlight, we can divide sunlight into three parts;

1) Invisible light – ultraviolet light (light that cannot be felt by the human eye), with a wavelength range of 250-400nm.

Ultraviolet light is further divided into three categories: long-wave ultraviolet light, UV-A: 315-400 nm; UVB, UV-B: 280-315 nm; Short-wave ultraviolet, UV-C: 250-280 nm. UV-C reaches the ground very little and is negligible.

2) Visible light (light that can be seen by the human eye), the wavelength range is 400-750nm, and the main components are red light, green light, and blue light.

3) Invisible light – near-infrared (light that cannot be felt by the human eye), with a wavelength range of 750-2500nm.

Near-infrared is a type of infrared, and infrared with a wavelength above 2500nm is called mid-infrared and far-infrared.

Among the components of the solar spectrum that reach the ground, the wavelengths that affect human health are:

1) Long-wave ultraviolet rays (UV-A), long-wave ultraviolet rays can darken the skin, cause skin pigmentation, and lead to skin aging. Excess UV-A can suppress immune system function.

2) UV-B, UV-B can cause skin redness, blisters, skin aging, which is commonly known as sunburn, UV-B can cause keratitis and conjunctivitis of the human eye, long-term sunburn can lead to cataracts and suppression of immune system function, and even skin cancer.

The ultraviolet effect described above refers to the long-term and high-intensity situation, the appropriate amount and short-term sunlight ultraviolet radiation is also beneficial, it can enhance people's physique and the ability to resist infectious diseases, promote the synthesis of vitamin D3 in the body, maintain normal calcium and phosphorus metabolism and bone growth and development, have the effect of accelerating wound healing, and can improve immunity.

3) The blue light part of visible light (wavelength 400-500nm), blue light has the highest photon energy in visible light, which can penetrate the lens directly to the retina, causing damage to the retina, resulting in vision loss, which may cause serious ophthalmic diseases.

High-intensity blue light damage to the retina of the human eye is much greater than the impact of near-infrared rays, the harm of blue light to the human eye has always existed in sunlight and artificial light sources, however, low-radiation blue light is also beneficial to the skin, infant jaundice is treated by irradiation of low-intensity blue light, blue light can also whiten skin and teeth; Blue light controls people's biological clocks to a certain extent; The stimulation of blue light stimulates our body to secrete cortisol, which can be exciting.

4) Near-infrared rays will make the human skin feel heated, and will also make the skin dry and lose moisture, resulting in rough skin, high-intensity near-infrared rays will cause skin burns, the human eyeball contains more fluid, and the absorption of near-infrared rays is strong, and high-intensity infrared rays will cause cataracts when they directly irradiate the eyes; Near-infrared rays are also beneficial, such as some medical devices that use near-infrared rays to irradiate parts of the human body, increase temperature, improve blood circulation, eliminate swelling and dissipate inflammation.

From the above analysis, it can be seen that ultraviolet rays, blue light, and near-infrared rays have an impact on human health. These rays of light can only have an impact on human health if they are exposed to high intensity or long periods of time, such as people who work outdoors in highland areas or long-day areas, have dark skin and are prone to eye diseases such as cataracts.

For the ultraviolet and near-infrared parts of sunlight, the use of shielding, sunscreen skin care products, anti-ultraviolet materials and other protective measures can effectively avoid the impact of sunlight on the human body, but, For indoor lighting sources closely related to our lives, if the selection and use of lighting is not appropriate, it is impossible to avoid the adverse effects of lighting light on health, people who work and live under low-quality lighting for a long time may be exposed to ultraviolet, blue light, infrared radiation, etc., resulting in dry skin, pigmentation, wrinkles, retinal damage, etc., so that the skin and eye vision appear aging in advance, the following figure can strongly warn us that the radiation safety of the lighting source is very important.

In order to ensure the reasonable specification of the lighting source in the manufacture and application, the lighting source should meet the national standard (GB/T 20145-2006 photobiological safety of lamps and lamp systems), in fact, many lighting products are not marked with these parameters, even if the radiation parameters are marked, it is difficult for us to judge the authenticity of these radiation parameters, we present the full spectrum of various commonly used lighting sources to you through professional-grade spectral analysis methods, so that the impact of the light source on health becomes clear at a glance, For lighting sources, scientific defense is the most effective means of dealing with hazards.

The wavelength range tested by the conventional spectrum analyzer is 400-800nm, and the spectral map of this range can not fully reflect the impact of ultraviolet and infrared rays on health, by using professional-grade full-spectrum analysis methods, the spectral analysis is extended to the range of 350nm-2450nm, and you can see whether each light source has adverse effects on the human body. The following full-spectrum diagram of artificial light sources will hopefully help you clearly understand the health effects of artificial light source lighting.

The impact of lighting on health is not only the spectral composition of the light source, but also the electromagnetic radiation of the lighting driving part, noise, glare of the light source or lamp, the strobe of the light source, the safety of the lamp and other aspects, these aspects can be solved by some protective measures, however, whether there is harmful wavelength radiation of the lighting source itself needs to be taken seriously.

It should be emphasized here that the impact of harmful wavelengths in the spectral composition on human health is mainly determined by the intensity of light irradiation of this wavelength and the time of irradiation, if the irradiation intensity is within the safe range specified in the national standard, the impact of long-term exposure on human health beyond the harmful distance is still safe, so seeing the presence of harmful wavelengths in the spectrum does not mean that there must be adverse effects on health.

In fact, these light sources have been with people's work and life for many years. It should be noted that the basic components of all lighting sources are red light, green light and blue light, and the impact of the blue light part of the lighting source on the retina of the human eye has always existed, and will always accompany human life.

incandescent lamp

The full spectrum of incandescent lamps is shown in the figure below, and incandescent lamps are widely used in various lighting occasions and have many applications.

Health effects in the incandescent spectrum:

1) The ultraviolet UV-A content is very small, and the health effects of ultraviolet rays can be ignored.

2) Ultraviolet rays (UV-B) content: None.

3) The content of blue light components is small, and the irritation to the eyes is small, and the blue light contained in the incandescent spectrum is the safest for indoor lighting.

4) High near-infrared content, long-term lighting will cause dry skin and wrinkles; The surface temperature of the light source is high and it is easy to burn.

Long-term direct exposure of high-intensity infrared rays to the eyes can also cause cataracts.

Due to the low luminous efficiency and high energy consumption of incandescent lamps, they have been phased out. From a health point of view, incandescent lamps are the least impactful.

Halogen lamps

The full spectrum of halogen lamps is shown in the figure below, halogen lamps are widely used in effect lighting, such as indoor spotlights, which are more widely used.

Health Effects in Halogen Lamp Spectroscopy:

1) The ultraviolet UV-A content is very small, and the health effects of ultraviolet rays can be ignored.

2) Ultraviolet rays (UV-B) content: None.

3) The content of blue light components is small, the irritation to the eyes is small, and the blue light contained in the halogen lamp spectrum is safe for indoor lighting.

4) High near-infrared content, long-term lighting will cause dry skin and wrinkles; The surface temperature of the light source is high and it is easy to burn.

Long-term direct exposure of high-intensity infrared rays to the eyes can also cause cataracts.

Due to the low luminous efficiency and high energy consumption of halogen lamps, halogen lamps have been phased out. From a health point of view, halogen lamps are less impactful.