Wristwatches with never-fading numbers and hands are always popular among the stronger half of humanity. There are many rumors about them mortal danger, because their almost “eternal” luminescence is based on radium or tritium radioactive light mass, which ensures clear visibility of the chronometer even in pitch darkness for many years. Let's try to figure out what's true and what's a lie.
The first radioactive clock
In 1914, the American company U.S. Radium Corporation began producing wristwatches under the Undark brand with luminous dials, the surface of which was completely covered with radium-based paint. In 1916, she patented Radiomir, a luminescent powder based on radium, which made it possible to create perfectly readable markings in the complete absence of light.
The paint held up perfectly under water, so it began to be used to mark the numbers and hands of watches produced by the factory for submariners. Considering the 1602-year half-life of radium-226, it should have ensured the continuous glow of the markings for hundreds of years.
With the outbreak of World War I, products with new light indications began to be in demand among the military. Fulfilling a government order from the US Defense Department, the owner of Radium Corporation hires young girls to hand-paint hands and dials. While drawing arrows and numbers, the workers licked the brushes, trying to make them thinner, and radioactive radium penetrated their bodies, irradiating organs and tissues.
The Case of the Radium Girls
Subsequently, all the girls fell ill with severe skeletal lesions, many of them had osteonecrosis of the jaw and pathological bone fractures. Several of them sued the company, demanding monetary compensation for the physical and mental harm they suffered. A long trial began, which became known as the “radium girls” case. Ultimately, they were able to reach a settlement with the corporation and received $10,000 plus another $600 for each year they worked at the plant.
Radiomir special watches for divers
On the eve of World War II, Radium, renamed Officine Panerai, developed the Radiomir wristwatch for submariners of the Royal Italian Forces with a large waterproof case and luminous numerals. According to Navy archives, only ten were produced. Later models used a different marking method: the entire dial was painted with radium, which was then covered with a thin plate with cut out numbers and hour markers.
The glow of the chronometer was so bright that the soldiers had to cover it so that opponents would not notice it in the dark. Submariners did not suspect that the products were deadly until the cities of Hiroshima and Nagasaki suffered from atomic explosions, and hundreds of thousands of people suffered lethal doses irradiation.
Most of the Radiomir watches were sealed in a concrete container and sank to the bottom of the Mediterranean Sea. The sold copies, despite the radioactive danger, are considered to be of rare value, and many collectors are not averse to adding such rarities to their collection.
Why are radium-based wristwatches dangerous?
Conventional wristwatches contain up to 4.5 microns of radium, which, together with its daughter products, forms α-, β- and γ-irradiation. Gamma rays easily penetrate through watch glass into muscle hands, leading to radiation dose accumulation of up to 4 rads per year. If the dial is at the level of the gonads, the most radiosensitive cells, 16 hours a day, they can receive a radiation dose of 1 to 60 mrad/year. Taking into account the natural radioactive background, such additional radiation contributes to the occurrence of chromosomal mutations and the appearance of hereditary diseases in offspring.
This is why the IAEA banned the use of radium in watch production in 1967 and recommended replacing it with radionuclides with weak beta radiation: tritium (H3) or promethium (Pm147). Beta particles have a short range and are completely absorbed by the metal casing wristwatch, making them safer for human health. The only disadvantage of the tritium composition is that if the seal of the housing is broken, the radionuclide can penetrate human skin and cause local tissue irradiation.
Tritium backlit watch
Due to the danger of radium powder, manufacturers have made attempts to replace it with safer light compounds. Thus, in 1949, a new luminous substance based on tritium, called Luminor, was tested. Well-known brands Omega and Rolex used it to produce a special series of wristwatches for submariners. Due to the relatively short half-life of the radionuclide - about 12 years, the luminescence deteriorated over time, and the company proposed reapplying the light mass in the factory.
In addition, many users were concerned about the possible penetration of isotopes through the body, especially in those models where there was a large amount of tritium paint. Plus, some countries have restricted the import of radioactive substances into their territory, as a result of which watch sales have fallen. In this regard, in the 90s, Swiss manufacturers stopped using tritium powder to mark dials, replacing it with safer luminescent compounds.
Interesting fact
In 1975 it was adopted international standard, allowing the use of only two radionuclides - tritium and promethium, with restrictions on their radioactivity. From then on, watch manufacturers were required to mark their products with tritium emitting no more than 7.5 mK or "Swiss T" as "T Swiss made T".<25», если излучение не превышает 25 мК.
The revival of wristwatches with radioactive illumination
Despite attempts to develop safe radioactive light masses, nothing better than tritium was invented. And in 2000, it again began to be used to mark dials, but in an updated form. MB Microtec Corporation has developed a safer technology based on radioluminescence of tritium light compounds, called PLT - Permanent Light Technology. It was subsequently renamed Tritium Gas LightSystems (TGLS) or Trigalight. Since 2008, the company began producing its quartz watches with trigalight markings under the Traser brand, which were immediately appreciated by the military.
Operating principle of "trigalight"
A glass tube 0.5-0.9 mm thick and 1.3-6.6 mm long is painted from the inside with a zinc sulfide phosphor, then filled with tritium gas under pressure. When exposed to gamma particles emitted by tritium, it glows in the dark without additional recharging from sunlight. The glow is green, but by varying the thickness of the glass, pressure and gas concentration, you can get red, blue, yellow or white illumination. Unlike powdered light compounds of yesteryear, tritium gas has a more intense and stable glow.
Trigalight: safe or not?
The innovative technology for manufacturing radioluminescent light sources "Trigalite" is considered safe for humans for several reasons
- The thickness of the phosphor and the walls of the sealed capsule is sufficient for complete absorption of beta particles released by tritium. As studies have shown, electrons have low energy and spread in the air only 1-3 mm.
- Cutting and soldering a long glass tube into the required sections is carried out simultaneously with a special laser. The beam cuts the workpiece into capsules, instantly melting their ends, after which the resulting “trigalights” are tested for leaks in a dark room.
- “Trigalites” are secured to watches in the most reliable way: a hole is drilled in the dial or on the hand, where a flask with tritium is placed.
Today, Microtec produces two types of capsules - T25 and T100 with different luminous intensities, which are used by many watch manufacturers to mark hands and dials. For example, the Swiss brand Ball and the American company RBMG, which created Luminox watches exclusively for US Navy special forces.
Wearing a Ball watch with tritium backlight every day for one year is 2000 times safer than one flight of 2400 kilometers.
Popular brands of Trigalight illuminated watches
1.Smith & Wesson. Since 1950, the American company Smith & Wesson has been producing watches with tritium backlight for hunters, the variety of which is amazing: from wrist watches to chronometers on key fobs and hunting rifles.
2.Precista. Since the 50s of the twentieth century, wristwatches have been made exclusively for the British military. In the 80-90s, they were decorated with the “Broad Arrow” emblem and markings with the personal number of the serviceman. Since 2010, the brand was bought by the British company Timefactors, which switched to producing small batches of watches with a luminous dial based on a safe phosphor - Super-LumiNova C3.
3.Luminox. The manufacturer (Richard Barry Marketing Group) has been supplying watches under the Luminox brand to the US Navy special forces since 1994.
4. Traser. The Swiss corporation Mb-microtec produces Traser wristwatches. Designed for military personnel in England and the USA, due to their double body made of metal and carbon, tritium backlighting and a high level of water protection, they are eagerly purchased by intelligence officers, extreme sports enthusiasts, fishermen and hunters.
5.Uzi. The Israeli line of Uzi watches, named after the developer of the legendary submachine gun Uziel Gal, has found its admirers among both military and civilians.
6.Tawatec. Swiss Military Watch has created a special brand of watches, Tawatec, for underwater sappers and saboteurs of the US and Canadian armies. Currently, they are actively used by both the military and divers and water sports enthusiasts.
In the Soviet Union, several factories produced watches with radioactive backlight, but exclusively for the army due to the high cost of radium-226. Thus, the Chelyabinsk plant launched the production of the Ural wristwatch, which creates a radiation background of up to 7000 micror/h, and the Chistopol plant launched the “Kama” with radiation of about 1200 micror/h. Also, until the mid-60s, a number of other brands were produced - “Pobeda”, “Sports”, as well as chronometers for divers, which were often presented for anniversaries and birthdays to both military and civilians.
How to determine if a watch is dangerous or not?
The likelihood of finding a rare watch with radium backlight is small, but it is possible if the family has leftover rarities from grandparents. Such watches should have yellow-brown, cream or mustard markings that can glow in the dark. It will help to finally verify their radioactivity dosimeter RADEX, which has a highly sensitive Geiger counter that quickly and accurately measures both gamma and beta radiation. The device is easy to use, the received data is reflected on a large screen, and excess of the background is indicated by a sound signal or vibration.
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Can old watches really be radioactive? Let's try to separate facts from rumors and speculation, so as not to harm our health and not send an innocent rarity to a landfill in vain.
Three reasons
Number one. Numbers and arrows made of glowing radium
When luminous paint based on radium salts was invented at the very beginning of the 20th century, it delighted everyone so much that it was even used to paint Christmas tree decorations and children’s books. Glow-in-the-dark arrows and numbers were widely advertised, which were especially popular with the military during the First World War. They still emit radiation - up to ten thousand microroentgens per hour...
The civilian ones, which were smaller in size, used less dangerous paint. In addition, over time, expensive radium began to be spent on watches less often. And yet, such chronometers stopped being produced only in the mid-sixties.
Number two. Radium dial
Very rarely, there were watches whose entire dial was covered with paint containing radium phosphor. No expense was spared in the colors. It’s beautiful: all long night the clock spontaneously glows in the dark!..
Number three. Watch with radioactive contamination
Watch factories have nothing to do with it. We are talking about objects that have been in the radiation zone or doused with liquid containing isotopes. Radiation does not penetrate into the metal parts of the watch; it is present in dust and dirt that has clogged up in the cracks. If you disassemble and thoroughly wash the watch, you can get rid of the radiation. But you can’t wash a bracelet or strap, no matter how hard you try.
Despite the fact that most of the tales about radioactive watches are associated with this particular option, in 99 percent of cases, chronometers produced using radium paint are really dangerous.
Danger level
Cancer can be caused by radium entering food or the lungs through inhalation. If you constantly carry radioactive antiques and do not wash your hands after touching them, of course, there will be no benefit. Judge the degree of harm using the following figures.
The danger is posed by background radiation above 200 microroentgens, provided that a person remains in the place of its exposure during the working week, that is, forty hours. The radiation of the watches considered in the first (most common) version is 80–250 microroentgens/h on the front side and from 30 to 70 microroentgens on the back side, where the background is screened by a lid and a thick watch “filling”. That is, the radiation falls within the acceptable limits for those working at the site.
Is it possible to rid watches of radiation?
Can. But the procedure is troublesome and painstaking. It is performed with gloves and requires lengthy preparation.
Clean the table, cover it with several layers of disposable napkins, and bring a container of water. Immerse the watch parts there sequentially. Radioactive paint must be softened and removed under water (dust should not fly in different directions) with special sharpened sticks.
In nine cases out of ten, it is possible to completely get rid of radiation or at least bring it to a non-hazardous level.
Of course, any fanatical collector would never agree to spoil a rarity by scraping off the radium paint. Well, if you don’t wear 800 micro-roentgen on your hand for days, but store it in a hermetically sealed plastic bag, there won’t be much harm. Just remember, after showing off your watch to your friends, to thoroughly wash your hands and wipe the area where the antique was kept with a damp cloth.
More about precautions
First, use a dosimeter to find out whether your watch is radioactive. (You need to measure in the area of the dial).
The most dangerous are dust particles from crumbling luminous paint. Radiation is revealed by its darkening, swelling, and gray-brown tint. You cannot open your watch or lean close to it. Keep children away from the collectible item. After “communicating” with him, do not skimp on water and soap when washing your hands.
Have you ever wondered what is stored in your closets, atresols and pantries? From personal experience, I know that many things lie there for years on the principle of “maybe they will come in handy,” and often even the owner of the apartment has a rather vague idea of what lies in the depths of the shelves. Meanwhile, there may be things very dangerous to health, the dangers of which their owners simply do not know.
On my blog I often write about traveling to radioactive places like Chernobyl or Pripyat. Such trips are relatively safe if radiation safety rules are observed. It is much more dangerous when radiation is closer than you think and you are unaware of its existence. I personally know a person who accidentally found one of the things I’m going to talk about today on the mezzanine of his home. What are these things? Why can they be more dangerous than a trip to the Chernobyl Zone? Let's get a look.
In this post we will talk about those things that contain radioactive substances that significantly exceed the safe norm - they can often be found in everyday life in the form of seemingly safe “souvenirs” and things left “as a memory.” First of all, this applies to various old measuring instruments (watches, pressure meters, etc.), the scales of which can glow in the dark. Until about the end of the sixties, such devices often used the so-called. “permanent light mass” (abbreviated as SPD), which contained radioactive substances - most often it was radium-226.
02. Here, for example, is a radioactive sextant. “Shines” approximately 2500 microroentgens per hour, which is more than 100 times higher than normal. The biggest danger of such a thing is not even the level of radiation (it is safe already at a distance of about 1 meter), but rather the fact that the scales with SPD are not protected in any way - which means that radium can be shaken out of the scale and contaminate surrounding objects.
03. Radioactive diving watch. Perhaps one of the most powerfully “luminous” things is that individual specimens can produce a beta/gamma background of up to 10,000 micro-Rentens per hour. Pay attention to the color of SPD - it has shades from yellowish to light brown. If the scales are exactly this color, then most likely it is radium, and not the safe phosphorus used in later models.
04. However, it is impossible to say with one hundred percent certainty about the color of the scale. I came across specimens with a white-greenish scale, very similar to phosphorus, but at the same time phoning. The best check is measurement with a dosimeter.
05. If it is not possible to check the watch with a dosimeter, then you can use this method - safe phosphorus reacts to “charging” with light, glows for some time in the dark, and then dims. Radioactive SPD does not react in any way to photons and either glows with a constant dim light, or does not glow at all due to old age.
06. Not only divers, but also ordinary household wristwatches can be radioactive. Here's an example of a typical SPD watch - the hands and numbers have yellow radium SPD on them, which is a hazard.
07. Here's another good example. I don’t know the measurement results of these watches, but judging by the amount of luminous mass, they should “shine” very well.
08. Not only watches, but also everything else that has “dials” can be radioactive. A similar compass with SPD (as in the photo below) was once kept in my home. And very often old aviation instruments “shine” - if you have something similar at home, be sure to check the thing with a dosimeter.
09. What else could be dangerous? Various “military souvenirs” like sights - without scales, but with luminous parts. Of course, it could be phosphorus, but it could also be radium. A sight with SPD looks like this:
10. Old smoke detectors can pose a radiation hazard - they do not have luminous scales, but contain radioactive substances (thorium, in my opinion). At a distance of 1-2 meters, such a smoke detector is completely safe, but in any case there is no need to store it at home, and certainly under no circumstances should it be broken - there is a danger of contaminating the room with radioactive substances.
11. Here's another radioactive object - an old icing sensor containing a powerful source of strontium-90. Such a sensor can be found in factories, repair shops, and even on the roof of your house. It's better to stay away from this kind of thing.
12. Radioactive toggle switches. This is an inconspicuous “switch” that can be found in household boxes with nuts, screws and other metal rubbish. The point on top of the toggle switch contains SPD - it is especially dangerous if the glass protecting the phosphor is cracked or broken - a couple of such toggle switches can be stained with radium in a very large area.
13. Toggle switches with SPD installed in the device:
The worst thing about all this is that particles of radium can enter the body and remain there - even with a small level of radiation, such a particle can “make a mess” in a few years. Another very important point is that SPD based on radium salts has another danger - radon released into the atmosphere. This is a very dangerous gas, which also has the ability to leak even through rubber seals - so no glass screens will protect against it.
14. Radioactive lamps of the DKShS-3000 type - a xenon arc lamp, one of the electrodes of which is radioactive. The item is relatively safe, but it is better not to store it at home.
15. Radioactive control sources from radiation measuring instruments. For example, such a source from the DP-2 radiometer “shines” very strongly in beta - to such an extent that when working with it it is advisable to use glasses to protect your eyes. Of course, it is highly unlikely that anyone would have such a thing at home, but you never know...
16. Some old camera lenses (mostly German and Japanese made) are also radioactive. This yellowish glass on the lens below contains a large content of radioactive thorium. Such optics were made until approximately the mid-seventies, after which radioactive thorium was replaced by non-radioactive substances. Takumar from the photo below is phonit in beta+gamma at approximately 3000 micro-Renten per hour.
At the same time, unlike all of the above, a lens with thorium glass is relatively safe - it does not emit radon, but it is still better not to use such things.
If you find any of the above on the mezzanines and cabinets at home, under no circumstances should you throw them away. You need to call the Ministry of Emergency Situations and hand over these things, they will dispose of them there. In general, take care of yourself and your loved ones :)
Wristwatches are one of the most common radioactive objects; they are often handed down from grandparents and kept as a memory, irradiating everything around them. The place where such watches are disassembled or broken turns into a hotbed of radioactive dust, the inhalation of which is guaranteed (sooner or later) to lead to a diagnosis of cancer.
They also emit the radioactive gas radon-222, and even if the watch is far from you, inhaling the radioactive gas for years is a big risk. The excess of the natural background in the immediate vicinity of such clocks ranges from 100 to 1000 times. The dose rate of some specimens exceeds 10,000 µR/h (100uSv/h).
Radiation... People are accustomed to identifying radiation danger with some kind of global catastrophes, and many do not even realize that they actually live side by side with objects that seem to have an absolutely peaceful purpose, but are fraught with an invisible and insidious danger. Take, for example, an ordinary wristwatch. Not modern ones, of course, but those that our grandparents wore and which perhaps someone keeps as a memory. In the post-war period, the watch industry widely used in the production of dials the so-called permanent light mass containing one of the most insidious isotopes, Radium-226.
Initially, the watch delighted the owner with brightly phosphorescent and undying numbers and hands, while quietly and imperceptibly irradiating him with Radium radioactive radiation. Time passed, the clock grew old, the phosphor faded as a result of its destruction by radioactive radiation, but Radium did not go away. He also continues to radiate invisible danger. Moreover, the danger is real. The equivalent dose rate of gamma radiation from the dials can exceed 1000 microroentgens per hour, which is 100 times higher than the normal natural background. A high level of radioactive radiation is not the only danger that lurks in the luminous markers of such watches. The fact is that Radium-226 decays to form the radioactive isotope Radon-222b, which is a gas and easily leaves the watch case.
But that's not all. As a result of radiation destruction, light mass becomes very fragile and easily crumbles. As a result of repairs or any actions with the watch, radioactive contents may come into contact with your hands and may subsequently be introduced into the body with food. In the Soviet Union, many brands of wristwatches were produced with radioactive marks on the dial and hands. They were produced until the mid-sixties of the last century. Such brands as “Ural”, “Kama”, “Pobeda”, “Sports” were produced, as well as special watches for divers.
But the most common radioactive clocks were those used in military equipment, aviation and the navy. They were a frequent gift given by colleagues to their comrade in arms on his birthday or upon retirement. The watches were, of course, given with all their hearts and the donors did not even know about the very unpleasant contents that could harm the health of the owner of such a watch, and they took their place of honor somewhere on the wall or bedside table, quietly irradiating all the inhabitants of the house day after day. The most generous amount of luminous mass was applied to the so-called cabin wall clocks. The dose rate of gamma radiation on some examples of such watches could reach up to 100,000 µR/h!
Aviation clocks of the AChS type became widespread, as well as clocks installed in armored vehicles, which kept time not only on board an airplane or tank, but also at home and in cars, where they were built in by fans of military equipment.
There is also a high probability of detecting radiation in captured German watches from the Great Patriotic War. But, unfortunately, it is impossible to say for sure whether a grandfather clock or a watch bought in an antique store is radioactive. But this is very easy to find out if you have at your disposal a portable dosimeter RadiaScan-701. The device contains a modern highly sensitive Geiger counter “Beta-1”, which will allow you to quickly and accurately assess the background radiation at home and in the country. Will allow you to identify sources of radioactive radiation that you may encounter in everyday life. After all, radioactive watches are only a small part of an extensive list of items, military and civilian items, fraught with invisible danger. As the saying goes, “Forewarned is forearmed,” and knowledge, supplemented by a modern device, will allow you to protect yourself and your loved ones from radiation danger. We will tell you about other things and objects, for example, some models of home table or wall clocks that pose a danger, in the next article in our catalog.
15/11/2002
What danger to human health can something as seemingly harmless as a watch pose?
What danger to human health can something as seemingly harmless as a watch pose?
The answer seems obvious: the broken glass of a wristwatch threatens a cut wound, and if you collide with, say, a grandfather clock in the dark, you can easily break your forehead or bruise your ribs. But seriously, two things in watches can pose a danger to our health:
And the shooter
Materials and coatings of cases and bracelets
When the need arose to create watches whose readings would be visible in the dark (and this happened shortly before the start of World War II), manufacturers solved this issue quickly and simply: they began to cover the dials and hands with radioactive materials. No, no one wished harm on anyone, it’s just that at that time only very few nuclear physicists knew that radiation was not a useful thing. Well, when the whole world learned about it after the US Air Force nuclear attack on the Japanese cities of Hiroshima and Nagasaki, they decided to get rid of the watch, which posed a real danger to humans, once and for all.
It is known, for example, that the radiation level of the Radiomir Panerai watch from the Italian company Officine Panerai released at the end of the war exceeded permissible standards so much that the entire batch intended for the underwater special forces of the Italian Navy was buried in a concrete container at the bottom of the ocean. This brand is still produced, but radium, of course, is no longer used to illuminate the dial and hands.
Currently used glow-in-the-dark materials can be divided into two groups. The first and very popular are light-accumulating paints. They are absolutely harmless to health. True, in order for such paint to glow, it must first be “recharged” - held in the sun or under a bright lamp. After this, for some period of time you will be able to find out what time it is, even in pitch darkness.
The second group is compositions based on the radioactive isotope of hydrogen - tritium. These do not need recharging, they glow on their own. At the same time, such materials are by no means eternal: the material gradually disintegrates (the age of tritium is 25 years), and over the years it seems to “evaporate.” So when you notice empty holes on the hands and markers of old watches, know that there was once a tritium-based material there.
According to the standards in force in Switzerland, the letter T is placed on the dial of “tritium” watches. Usually these are watches for scuba diving and other extraordinary activities. By and large, tritium is also harmless to humans, since the range of the emitted electrons is very short (they barely reach the watch glass). It is harmful only in industrial quantities, for example, during production. In the entire Soviet Union there were only two workshops (in Chistopol and Chelyabinsk), where elements of watches and other devices were decorated with tritium.
The radiation dose received by a person when wearing a watch with a radioluminescent dial for a year is 20 times less than the dose received from an X-ray and 525 times less than the dose received by a person within 12 months from natural background radiation. Thus, luminous materials used in watches today do not pose a health hazard.
However, a watch consists of more than just a dial and hands. Some cases and bracelets can also pose a hazard. And the most harmful material used in watches is considered to be nickel. It can cause skin diseases, allergies, burns, itching and other sores. But each person’s sensitivity to nickel is individual, and approximately the same number of people do not tolerate contact with this metal as suffer from, say, cats. Nevertheless, you need to think about everyone, which is why there are standards defined by GOST for the release of nickel in watches. Before going on sale in Russia, all watches, in theory, must successfully pass the nickel release test.
Nickel may be present in the steel of the case and bracelet, but this content is very small. Much more dangerous is the nickel contained in the plating of watches. A number of properties of this metal have led to its widespread use not only in watches, but also in the manufacture of various accessories - belt buckles and handbags, hairpins, jewelry, etc. By the way, they are also subject to regulatory requirements for nickel content.
Nickel release problems most often occur in cheap watches. Although, of course, it’s not a matter of price, but, above all, of production technologies. The plating of some watches consists of a layer of nickel and a layer of decorative coating - usually chrome (if the color of the plating is white), titanium nitride or gold plated (if the color of the plating is yellow). So, sometimes the thickness of the outer coating is so insignificant that it quickly wears off, exposing the nickel hidden underneath.
Decorative coating is always used in watches made of brass or alloy (an alloy based on zinc, aluminum, lead and other components). However, you should not be afraid: not all watches made of brass have nickel in their coating.
Modern technologies do not require the use of nickel as an underlayer material, and all more or less serious companies have long ago modernized their production, since in Europe the sale of watches with a nickel base is simply prohibited. But if you are still afraid of this metal, buy a watch made of steel or titanium. They are absolutely safe because they contain no nickel at all.
Theoretically, a watch strap can also pose a danger, since a solution containing nickel salts is also used when making genuine leather products. This means that a small amount of harmful metal may remain in the strap. However, no one in the watch business has ever heard of a customer being allergic to straps.
At one time, doctors probably expressed fair concerns that the first models of quartz watches used batteries that contained mercury compounds. However, this was quite a long time ago, and as for modern batteries, they are not able to cause any harm to the owner of the watch. This does not mean that they can be disassembled or swallowed. We don't recommend it.
In general, as you probably already understood, watches that are harmful to health are not produced today, and everything depends primarily on the individual characteristics of your body. One begins to choke in the presence of cats, another cries in the spring, a third has an itchy wrist from a leather strap, and doctors do not recommend that severely hypertensive patients wear watches even made of pure gold in the heat. As for individual characteristics, they were once taken into account even when hiring for watch factories.
In addition to the standard medical examination, candidates underwent a sweat test for acidity. If certain standards were exceeded, the path was closed to a person, for example, for assembly, since if a person with high acidity of sweat touched the dial, after a few months it would begin to darken and may even rot entirely.
Most experts believe that fears associated with the dangers of watches are greatly exaggerated. All watches sold in Russia undergo special tests and receive a certificate confirming their safety for the consumer.
