Fitolamps have a lot of advantages — they help to grow mini-gardens with herbs and strong seedlings in the winter in the house. However, the light from them is unusual for the eye, and many fear harm to vision. Healthyinfo tells about the harm from phytolamps — imaginary and real, how different spectra affect a person and which phytolamps should be chosen.
What scares most those who are not familiar with the features of plant lamps? The most common concerns:
Harm from ultraviolet radiation;
Dangerous blue spectrum;
To understand exactly, two important concepts must be distinguished:
Rejection of the light of the phytolamp. If this red-blue spectrum (which glows either as a stable pink-violet or changes throughout the day) just irritates the eyes and doesn’t like it, this is a matter of personal preference, more towards psychology and emotions. If there is such a problem, there is only one solution — to remove the lamp from the field of view;
The real potential harm from phytolamps, which we will deal with in detail.
UV rays can really be dangerous — they cause burns to the skin and cornea, provoke cancerous changes. But to understand harm, you need to remember the theory.
The sunlight itself (which, in theory, phytolamps should imitate) is not white, it has several colors — green, red, blue, as well as ultraviolet and infrared rays invisible to us. We notice the influence of ultraviolet by tanning, infrared rays — by the sensation of heat.
In ultraviolet there is a gradation of radiation:
Soft, 315–400 nm;
Medium, 280–315 nm;
Rigid, 100–280 nm.
The most dangerous is, of course, hard radiation. Although there is more dangerous, extreme. It and hard radiation are called “vacuum”, since in nature they are absorbed by the atmosphere and do not reach us.
But even medium-length UV rays with direct exposure can cause corneal burns.
Hard UV radiation is used in lamps for disinfection, quartzization of rooms from viruses and bacteria. UV rays with a range of 240–260 nm destroy any DNA.
Of all the theory, you need to remember the main thing: really harmful ultraviolet has a length of 10–400 nm. However, humanity also uses such rays with benefit — of course, in the absence of direct contact with the person himself. But in phytolamps, everything is different.
What spectrum do plants need?
What do plants need from the entire spectrum listed above and how can this light affect a person?
In a series of experiments, scientists found that not all spectra are really needed by plants. Efficiency was assessed by the level of photosynthesis.
If the plant is under red and blue-violet rays, then the maximum absorption of carbon dioxide begins.
The green spectrum without additional rays has practically no effect (for this reason, green greenhouse film is just a marketing ploy). Plants do not absorb green rays, but reflect — in fact, that’s why they are green in our eyes.
That is, from the entire spectrum, plants need blue waves (range 440–460 nm) and red (635–665 nm) the most.
It is interesting!
Under the rays of blue, plants grow better — green mass, stems, leaves increase.
Red is necessary for seeds to germinate, plants to bloom, and fruits to ripen.
In the mornings, the sun emits more blue spectrum rays, and in the evenings — red ones. Therefore, people wake up more easily (and fall asleep worse) in blue light, and we watch sunsets in red. This is how our biorhythms work.
LED phytolamps: is there any UV?
Most LED fitolamps just have peaks in the blue and red areas. Unlike the sun, their spectra do not change during the day (this is only in expensive models of phytolamps).
There is no UV radiation in LED phytolamps. Neither sunbathing, nor drying varnish, nor getting vitamin D or corneal burns under such lamps will work.
Soft UV rays with a range of 380–390 nm are in specialized LEDs that are not used in crop production. For example, recently scientists from Israel (Journal of Photochemistry and Photobiology B: Biology) proved the effective effect of ultraviolet LEDs on a new coronavirus — the causative agent of COVID-19. What is attractive is that this technology is cheap and available for use in commercial premises and private homes. But it is not used in phytolamps.
So LED phytolamps can only irritate — but not harm health with UV rays.
Ultraviolet in fluorescent phytolamps
However, this statement does not apply to fluorescent lamps: they just emit ultraviolet light. It is the basis for the operation of such devices.
Fluorescent lamps are not recommended for homes. In them, UV rays are reflected from a flask coated with a phosphor and converted into the visible spectrum. And even in a new lamp, coating inhomogeneities or microcracks are possible, through which the rays go out.
Over time, the phosphor ages and cracks, UV radiation becomes more. In critical cases, radiation can reach the same level as exposure to the bright rays of the sun. Unless, of course, look directly at the lamp. At the same time, the red-blue spectrum, which is unpleasant for many, comes from such phytolamps less.
When using fluorescent phytolamps, there is a risk of harm to the eyes. This can be avoided by using them in ducts that limit the beam angle and only allow light to reach the plants.
Is blue light harmful?
In most phytolamps, the red spectrum predominates — so as not to grow huge plants in the house, but to help germinate or harvest. But the blue spectrum is also needed, and now it can harm if it gets into the eyes — from a minimum distance and for a long time.
Lamps with only a blue spectrum negatively affect the retina — the pupil does not narrow to the required diameter. But if there is a red component, then the reaction of the pupil will be corresponding to the radiation.
However, an excess of blue light in the afternoon can interfere with circadian rhythms, causing sleep disturbances. So phytolamps can cause insomnia — although TVs, smartphones and other gadgets are much stronger.
So, an excess of blue is harmful, but this does not apply to bicolor phytolamps or, moreover, to pure red lamps. If there is a suspicion that sleep was disturbed precisely because of the lamps for plants, block them or turn them off earlier.
The biggest nuisance of phytolamps (although other lighting devices too) is the pulsation of light. To a large extent, it depends on the power supplies or lamp drivers. It is believed that a light pulsation of 2–3% is absolutely safe, and according to the norms, a range of up to 10% is allowed.
The pulsation of light is not visible to the naked eye, but if you point a smartphone camera at the lamp, you can notice this flicker (as on old computer monitors without cameras).
Due to the fact that we see, but do not realize this flicker, our eyes get tired, a tension headache, irritability may develop. Such a defect can be in many light sources, not only phytolamps. The solution is the same — to fence off the bulbs and not use them at night (12 hours is enough for plants, and you can use special timers that turn on the lamp early in the morning).
So, phytolamps have disadvantages. However, they are associated with the quality of devices, and the harm even from the cheapest is greatly exaggerated. And, of course, opinions about corneal burns, a dangerous blue spectrum, or a pulsation that is detrimental to the psyche are nothing more than myths.
Well, if the light from the bulb for plants is unpleasant for you, and in addition various symptoms appear — dry eyes, sleep disturbances, nervousness — then you should not only remove the phytolamp, but also check the room for air humidity and other sources of blue or pulsating light. There are much more of them around us than in phytolamps.