Contents
Microorganisms surround a person in everyday life everywhere: at home, at work, in public transport, in crowded places. However, many of them are pathogenic. With a small accumulation of pathogenic viruses and microbes in the environment, the human immune system copes with them. When the concentration of pathogenic microorganisms becomes excessive, no immunity can withstand such an attack: an infectious disease occurs.
There are two ways to avoid the disease: increase immunity or reduce the concentration of microbes at the place of residence of a person. If a healthy lifestyle, hardening, herbal remedies, immunomodulators helps to cope with the first task, then it is more difficult to cope with the second. Airing, wet cleaning and disinfection only temporarily reduces the concentration of infectious agents. In some cases, it is not even possible to carry out these preventive measures, for example, in rooms where people are constantly present. How to get out of this situation?
One of the ways to effectively reduce the number of microbes in a room is to irradiate it with a bactericidal spectrum of light using special devices – bactericidal irradiators.
Principle of operation
It is known that light waves of different wavelengths have different properties. The ultraviolet (UV) light beam has bactericidal properties. Ultraviolet radiation is divided into 3 ranges: short-wave (100-280 nm), medium-wave (280-315 nm) and long-wave (315-400 nm).
Long-wave radiation affects the photochemical processes in the body – it causes skin pigmentation. For disinfection purposes, this spectrum is useless.
Waves of the middle length of the UV spectrum exhibit an erythemal effect on the skin, promote the production of vitamin D in the skin, strengthen the immune system, excite the nervous system, and increase the level of hemoglobin in the blood. This range is used in physiotherapy.
For air disinfection using UV radiation, its short-wave spectrum is important. However, short UV waves, when they hit the retina, damage it, which is dangerous for the development of various eye diseases. In addition, UV waves less than 200 nm in length have an ozone-forming ability: they interact with oxygen molecules, forming ozone in the air. In large quantities, ozone is harmful to microorganisms and toxic to humans. The concentration of more than 0,22 mg of ozone in 1 cubic meter of air for a person is considered the maximum permissible.
The source of the ultraviolet spectrum of the short and medium ranges are bactericidal lamps. To get rid of the ozone-forming range of UV radiation, germicidal lamps have been constantly improved since their inception.
History of creation
Back in 1801, German chemist I. Ritter discovered ultraviolet radiation, and in 1892, English scientist G. Ward proved the bactericidal properties of this light range. In practice, the ultraviolet spectrum began to be used only in 1906, when the German scientists Kech and Reshchinsky created the first arc lamp from quartz glass and mercury electrodes. This lamp was first used in medicine for the treatment of psoriasis in 1926.
Since the first germicidal lamps were made of quartz glass, they were called “quartz”. Over time, quartz glass was replaced by uviol glass, which reduced ozone-forming radiation, but the historical name “quartz lamps” remained behind them. The glass of modern germicidal lamps is coated with titanium oxide, which completely absorbs the ozone-forming spectrum.
Types of irradiators
For ease of use, bactericidal lamps began to be used in special irradiators. Bactericidal irradiators are:
- Open (open type).
- Closed (closed type) – recirculators.
- Combined (can be used as open or closed).
They differ in their device and method of irradiating environmental objects, so their scope is different.
Open irradiators
Sources of UV radiation in open-type devices are not covered by anything. This makes it possible to disinfect the air and all surfaces 360° from the lamp. Since ultraviolet waves propagate unhindered, the stay of people, animals and plants in rooms that are disinfected by an open irradiator is prohibited.
There are modified open-type irradiators with rotary lamps, or additionally equipped with a protective screen. When decontaminating with the help of modified open-type devices, people can stay indoors for a short time.
The danger of an open source of UV rays is the reason for the limited use of open irradiators – only for strictly medical purposes (in operating rooms, manipulation rooms, laboratories). After disinfection with an open irradiator, the room must be thoroughly ventilated in order to remove ozone from it as much as possible.
Closed irradiators
The source of UV rays in this instrument is located inside the case. Air disinfection takes place inside the irradiator. It gets there forcibly – with the help of a built-in fan. Ozone-free bactericidal lamps are installed inside the housing. Thus, the negative impact of UV waves on humans, animals and plants is completely excluded, so closed-type irradiators can be used in rooms where people are constantly present.
Air disinfection can be carried out for a long period of time, and after the procedure, mandatory ventilation of the room is not required. Such devices are allowed to be used both in medical facilities and in office rooms, production workshops and at home.
How to choose
When purchasing a bactericidal irradiator, you must be able to choose it correctly. In addition to the intended purpose, you should be guided by:
- The performance of the device. The performance of the irradiator is determined based on the volume of the room (area in sq.m, multiplied by the height of the walls in m). The maximum deviation of the factory output of the irradiator from the actual volume of the room should not exceed 20%. Otherwise, disinfection will be ineffective.
- installation method. The irradiator can be wall-mounted or mobile (portable). Wall units are cheaper than mobile units. Wall appliances are recommended to be installed at a height of more than 1 m from the floor, which must be considered before purchase.
- Control system. Useful functions on UV irradiators are lamp status detection, control of hours worked, timer, delayed start. These options allow timely disinfection of premises, as well as timely maintenance of the device.
- Hull material. The metal case of the device is more reliable and durable. The body material of the portable model is especially important, as it is more prone to damage. Open UV rays are dangerous to humans, so the device must not be operated with a damaged case.
- Filtration system. Additional air filters clean the disinfected air from dust. If the device has air filters, make sure they are removable or replaceable. If there are replaceable disposable filters in the device, you must take care to purchase them in sufficient quantities.
- Options. The box with the bactericidal irradiator must contain instructions and a warranty card. There is a paragraph in the manual indicating the complete set of the product. Before purchasing, you should check whether the actual equipment of the device corresponds to that specified in the instructions.
When purchasing an irradiator for the home, you need to give preference to wall-mounted recirculators. They are more reliable and safer to use, especially if children and pets live in the house.
Advantages of bactericidal irradiators
Indications for air disinfection in residential premises using ultraviolet rays are:
- treatment of diseases of the upper respiratory tract (only as part of complex therapy);
- prevention of exacerbations of bronchial asthma and allergic diseases;
- prevention of recurrence of streptoderma and other purulent skin diseases;
- prevention of seasonal viral diseases;
- prevention of complications after surgery.
Bactericidal irradiators are useful in those rooms in which people are often. Their primary task is to destroy pathogens and eliminate the mechanism of their transmission. With the help of UV radiation, it is possible to destroy up to 97-98% of viruses and up to 95% of vegetative forms of bacteria. Fungi and mold are less sensitive to UV, especially their spores.
Disadvantages of UV disinfection
The benefits of air disinfection in residential areas are undeniable. However, bactericidal ultraviolet irradiators should not be taken as a panacea for all infections. Wet cleaning in the room and regular ventilation will not replace any disinfection.
You can not abuse disinfection. Sterile indoor air is not only not useful, but also dangerous. Human immunity must constantly face infections in order to be in good shape. If there are few microorganisms in the environment, the immune system “relaxes” and stops producing protective antibodies. Getting into another environment, which is saturated with all kinds of microorganisms, a person who has been in disinfected rooms for a long time (often these are children of overly caring parents) easily becomes infected.
Incorrect disinfection in the room is also fraught with the appearance of resistant strains of microbes in the air of the room, which will no longer be affected by the normal disinfection regime.
Ultraviolet rays are unsafe for human health, as they provoke the formation of toxic ozone. Any damage to the irradiator (housing, protective screen) can lead to deterioration in health and other health problems for people in the irradiated room.
Exposure to ultraviolet radiation on the body is dangerous for patients with cancer, tuberculosis, acute pneumonia, high blood pressure, thyroid pathologies, gastric and duodenal ulcers, kidney or heart failure. It is not recommended to carry out disinfection in rooms where pregnant women and newborns are present.
To avoid possible health complications, before purchasing a household bactericidal irradiator, you should consult with your doctor, and before using it, carefully read the instructions and follow all the necessary requirements for its installation.
- Sources of
- Vashkov VI – Means and methods of sterilization used in medicine. – M.: Medicine, 1999. – 368 p.
- Kryuchkova OB – A new generation of ultraviolet bactericidal irradiators OBN-150-KRONT. – 2015