The thermometer is in every house and apartment. It can be called an essential item, which is indispensable for any ailments. And since most of this device contains mercury, and the case is made of glass, there is a high probability of breaking it by negligence. And here it is important to know how long mercury evaporates, what is its danger and how to eliminate the consequences.
Properties of mercury
Mercury is a metal that is marked as the 80th element in the periodic table. Being a cumulative poison, it belongs to the I hazard class. It is the only metal that does not solidify at room temperature, but remains in liquid form. The release of toxic substances begins when the temperature rises to +18 ˚С, and since mercury evaporates for a long time, this makes it especially dangerous.
A typical thermometer contains from 1.5 to 2 g of liquid metal - this amount is very large, and if it evaporates completely in a closed living space, the area of \u200b\u200bwhich does not exceed 20 m22, the concentration of toxic vapors will exceed the allowable rate of 0.0003 mg per 1 m3.
Evaporation rate of mercury
In one hour, 0.002 mg of mercury evaporates per square meter. Thus, it is easy to calculate the rate of its evaporation in a living room at room temperature by multiplying this figure by the total area (90 cm2) of scattered balls: 0.002 x 90/10000=0.000018 mg/hour.
But at the same time, certain factors will always affect the speed of this process: temperature fluctuations, the quality of air circulation, the surface area of scattered particles and the total amount of toxic substance. After all, it is not always possible to collect all the mercury. Some of it can roll under the baseboards, into cracks and small chips in the floors.
One small ball of mercury from a broken thermometer evaporates for a long time - at least 3 years. If the house has warm floors and rare ventilation, then this period will noticeably decrease, and, conversely, increase with constant ventilation.
You can also estimate how long it takes 2 grams of mercury to evaporate in a well-ventilated home. Having made simple calculations, we get a period of 30 years. But remember that everything is conditional.
If we talk about how long mercury evaporates on the street, then herethis period will also depend on environmental conditions. It is known that under the influence of direct sunlight and air temperature from +35 ˚С to +40 ˚С, the evaporation rate increases by 15-17 times. In the cold season, it decreases accordingly.
And do not forget that over time, the rate of evaporation of mercury drops - after a couple of weeks, about twice and so on.
How dangerous is mercury?
So, we have learned how long mercury evaporates in the room and at what speed this process takes place, from which it follows that 0.18 mg of toxic vapor is released in one hour. Comparing this figure with the maximum allowable concentration (0.0003 mg/m3), we see a rather strong excess. But that doesn't say anything yet. The fact is that the maximum permissible concentration is calculated taking into account the initial criteria - the threshold concentration for a long time - from six months to a year, and plus a guarantee amendment is applied to this, which reduces this value by several times.
There is another value, which is defined as a weekly dose of mercury for a person. It is 5 mg per 1 kg of weight. Thus, it is not difficult to calculate the maximum allowable dose for each family member. And taking into account the volume of air consumed by a person (25 m3 per day), we can calculate the maximum allowable dose. To do this, we multiply this value by the permissible level of mercury vapor (0.0003). We get 0.0075 mg per day. We calculate the weekly dose by multiplying the result by 7.
And in order to understand how dangerous mercury is from a broken thermometer, you should determine the volume of air in the room that absorbs evaporation. You can make calculations by multiplying the length of the room by the width and height of the ceilings. In general, you should immediately find out the volume of air in the entire apartment. This is due to the fact that the vapors of this substance are volatile, and since the mercury in the room evaporates for a long time, they will certainly spread throughout all the rooms. So, with a total area of 60 m2 and a ceiling height of 2.7 m, we get a volume of 160 m3. We recall that the air is not static; with normal ventilation, 80% of the obtained indicator is replaced in one hour. Thus, the circulation automatically increases the volume of air that consumes mercury vapor, up to 300 m3.
Now you can calculate the concentration of mercury. For this, the amount of evaporation (0, 18) is divided by the volume (300). The result is 0.006 mg per 1 m3. We compare with the acceptable level (0.0003) and understand that not everything is as bad as it might seem at first glance. Before us is a twofold excess of the dose, which is not critical. However, it should not be left without attention either.
Thus, knowing how much and how long mercury evaporates and disappears, you can easily determine its potential harm to a particular room and people living in it.
Symptoms of poisoning
Mercury from one broken thermometer does not cause irreversible changes in the functioning of organs, paralysis and deathwill cause. But still, the body is able to respond to harmful fumes with general weakness, decreased appetite, headaches, nausea, a metallic taste in the mouth and vomiting. And if such symptoms are observed, then the victim must urgently receive medical attention. In addition, since mercury from a thermometer evaporates for a long time, it will continue its effect on the body of a weakened person. And this, in turn, will aggravate the signs of poisoning, which will lead to bleeding gums, abdominal cramps, a sharp increase in body temperature and loose stools with blood and mucus. This condition requires urgent hospitalization.
Information about how long mercury evaporates and why it is dangerous is especially important for parents and women during pregnancy. In the main risk group are children who, with short-term inhalation, may develop kidney problems. Pregnant women should also beware - there is a risk of intrauterine damage to the fetus.
How to collect mercury?
Understanding how long mercury takes to evaporate and what the consequences are, everyone should be able to collect it. First you need to lower the air temperature in the room by turning off all the heaters. If it is cold outside, you can open a window, but only one, so that the draft does not break the scattered balls into smaller particles. In summer it is desirable to turn on the air conditioner. These measures will stop the process of evaporation of poisonous metal.
Directly for the cleaning itself, you will need a thincopper wire, metal filings or powder, a sheet of sandpaper, a sheet of plain paper, and a sealed jar.
Remove mercury with copper wire
Since mercury evaporates for a long time, and even intensively at high air temperatures, it is advisable to protect the respiratory tract with a gauze bandage before starting cleaning.
Then we take the wire and wind it in such a way that we get a bundle about 1.5 cm wide and 15 cm long. So that it does not fall apart during the cleaning process, we tie it in the middle with a thread or a small piece of the wire itself. We cut off the ends on both sides so that they look like brushes. Sandpaper remove all the varnish and bend the beam in half. As a result, both ends should be on the same side.
Around the loop we make several turns of adhesive tape. So it will be much more convenient for you to hold the resulting brush in your hand. Then, with your fingers, slightly open the cleaned area and bring it to the mercury balls. Copper will begin to amalgamate metal particles, and soon they will all be on its tips. Upon completion of the procedure, it is necessary to put everything in a jar (together with the wire) and tightly close the lid.
How to use metal filings for cleaning?
To do this, they should be scattered on the infected area and carefully rubbed into the surface with a dry cloth. As a result, all the crumbled particles of mercury will be on it. We put them in a jar along with sawdust and seal it hermetically.
This method of cleaning mercury is quite simple, butit is only suitable for smooth surfaces, such as linoleum, plastic, marble, etc. For surfaces with cracks and grooves, a different method should be selected.
Mercury on pile carpet
It is important to carry out a thorough cleaning here, as mercury from a broken thermometer evaporates for a long time. If not all of it is collected, toxic substances will continue to be released, gradually accumulating in the human body. At the same time, the symptoms of poisoning are invisible at first, the consequences can be felt after a few weeks. And this, in turn, will make diagnosis very difficult.
It is most difficult to collect all the mercury from soft coatings, especially if they have a long nap. But you need to try, otherwise the carpet will simply have to be thrown away.
Pour metal filings in the place where the thermometer broke, and turn the carpet to this area. We wrap the area with mercury with polyethylene, carefully beat it out and leave it to be ventilated. Dropped balls of mercury together with the film are sent to the jar and close it well.
Clean the rug without lint
It is much easier to remove mercury from such a coating than in the previous version. It is convenient to use a metal brush here, but you can also use a small syringe or syringe. Using the selected tool, we collect all the droplets of the substance and pack everything hermetically.
What can not be done with mercury?
Sweeping mercury with a broom, especially from a carpet, is strictly prohibited. So you will only break the particles of the substance, expanding the volume of evaporation. Also, do not vacuum the contaminated area, otherwise a warm engine will increase the evaporation rate, and the vacuum cleaner itself will subsequently have to be thrown away.
If the balls of mercury got on things, then they should be destroyed. Machine wash is prohibited, as it will not save clothes - they will become dangerous in the future.
It is not allowed to flush the collected substance into the sink or toilet, as it is heavy and will most likely remain in the elbow of the water supply. How long does mercury evaporate under such conditions? Long and intense. Thus, you will be constantly exposed to poisonous fumes.
Even if a jar with particles of poisonous metal has been carefully sealed, it should not be thrown into a garbage container or garbage chute. It will break sooner or later and other people will be in danger.
Where is mercury disposed of?
In general, if the mercury is on a flat smooth surface or on a lint-free coating, then it will not be difficult to collect it. In addition to the above methods, you can use a sheet of plain paper. But what to do next with this jar if you can’t throw it away? In this matter, special organizations can help, such as:
- sanitary and epidemiological service;
- Ministry of Emergency Situations;
- mercury recycling service.
You need to call one of them and take the jar of collected mercury to the specified address. Just be sure to make sure it's packaged carefully. By the way, it is also advisable to dispose of the clothes and shoes in which you cleaned. By thisreason, the collection of mercury is carried out with gloves and a special suit.
If the collection of mercury failed
When a thermometer breaks, mercury particles often fly quite far. They can get on upholstered furniture, in places where clothes and other things are stored, roll under a baseboard or end up in floor crevices. In such a situation, it is very difficult to collect all the droplets to the last. And only specialists can help here. Before the brigade arrives, you need to remove all people and pets from the infected premises and open the window.
After arrival, security personnel will set the level of mercury vapor concentration, conduct a thorough cleaning and mark items that will need to be disposed of.
