Despite the presence of electronic thermometers, mercury thermometers do not go out of use, they are in no hurry to refuse them either in hospitals or in everyday life. It is possible that mercury thermometers are superior to electronic thermometers in temperature measurement accuracy, but they are definitely inferior to them in safety.
Mercury, which is used in thermometers, is a unique substance. It is a silver-colored metal, but unlike most metals, it is characterized by a very low melting point - 38.8 degrees below zero, and at +18 degrees it begins to evaporate. In a living room, the air temperature is usually higher, therefore, if you break the thermometer, the mercury will immediately begin to evaporate.
Studies have shown that inhalation of mercury vapor causes molecular changes in the nervous system, reminiscent of Alzheimer's.
Substances containing mercury are toxic and belong to the highest hazard class. This also applies to its combination with oxygen. At room temperature, such a chemical reaction will not occur, but it will happen later, when the fumes of mercury together with atmospheric air enter the respiratory system. From the lungs, the mercury compounds will pass the blood and spread throughout the body, "attacking" various organs. Mercury ions are especially dangerous for neurons - they destroy the membranes of nerve cells.
Signs of acute mercury poisoning occur 8 or even 20 hours after the substance enters the body. The first symptoms are nausea and a metallic taste in the mouth. In the future, the temperature rises to 39 degrees, headache, cough, shortness of breath, bleeding gums, vomiting, abdominal pain, diarrhea, and a few days later the patient dies. It is very difficult to save a person who has been poisoned with mercury, because this substance is slowly excreted from the body.
The amount of mercury in a thermometer is not so large as to cause acute poisoning, and yet when such a volume of matter evaporates, its concentration in the air will exceed the permissible norm by 20 times. The main danger lies in the fact that mercury breaks down into tiny droplets that can get into any crevices or get stuck in the pile of the carpet, continuing to evaporate. Then the intake of mercury vapors into the body will become systematic, and there will be a danger of chronic poisoning.
Symptoms of chronic mercury poisoning are weakness, increased fatigue, deterioration of attention, irritability, headaches, dizziness, tremors of the limbs with excitement.
In the countries of the European Union in 2007, a ban was introduced on the use of mercury thermometers.
If a mercury thermometer breaks, you must immediately remove the children from the room and start collecting the mercury. Do not use a vacuum cleaner for this, do not throw the collected mercury into a garbage chute or sewer. It is necessary to carefully examine every crevice, crack, unevenness, it is advisable to use a flashlight, because mercury glistens when illuminated. If you suspect that the droplets have fallen under the floorboard, laminate or baseboard, they must be removed. Places where drops of mercury were found should be marked with chalk and should not be stepped on. Inspection of the premises will take a long time, every 15 minutes you need to go out into the fresh air.
Mercury must be collected in a glass jar with a tight lid, and then call specialists from the rescue service. To avoid poisoning, you should drink as much as possible.
A mercury thermometer is not dangerous if it is not broken, but no one is immune from such accidents. It is advisable to completely abandon mercury thermometers in favor of electronic ones, especially if there are children in the house.