Mercury is the only naturally occurring metal that remains liquid at room temperature. Under these conditions, it does not oxidize in air and does not dissolve in water and alkalis. It dissolves in cold nitric acid and heated concentrated sulfuric acid. Under normal conditions, it actively evaporates, and the rate of this process is directly proportional to the temperature and surface area of evaporation. Mercury vapor is odorless and colorless and can only be detected in the air with the help of special instruments.
Mercury is characterized by low viscosity and high surface tension. These properties cause two negative processes in terms of mercury pollution of the environment.:
Mercury vapor is highly volatile, and a layer of water or other liquid does not present a real barrier for them. The same can be said for many building materials such as concrete, brick, paintwork, linoleum or tile. Mercury vapor evenly impregnates them throughout their entire thickness, and is also easily absorbed from the air by wood, carpets and fabrics. With an increase in temperature or mechanical action, mercury is desorbed back into the room air..
Pure metallic mercury dissolves many metals well, thereby reducing the strength of metal structures, and forms unstable compounds with both inorganic and organic substances..
For all living things, mercury and its compounds are the strongest poison that can cause:
The main routes of mercury entry into the body are inhalation of its vapors with air or ingestion with food or water. The human body removes no more than 20% of the mercury that has entered it, and it accumulates in the kidneys and brain, affects the fetus if the woman is pregnant, and is found in the blood and breast milk. At a mercury vapor concentration of more than 0.1 mg / m3, acute poisoning occurs, the signs of which are:
Long-term exposure to low doses of mercury results in chronic poisoning, which can occur with a delay of several years. All this time, irreversible disorders accumulate in the body with such external signs:
There are both natural (deposits) and man-made (mining sites, mining and non-ferrous metallurgy enterprises, special storage sites, waste products from burning oil products, etc.) sources of mercury polluting air, water and soil. Household and industrial premises are contaminated with mercury due to improper operation of mercury instruments and devices, such as thermometers, pressure gauges, electric current rectifiers. Statistics claim that 80% of all the work of the Ministry of Emergency Situations in St. Petersburg is a source of mercury vapor. Malicious mercury spills aside, the most common reason for their existence is a broken mercury thermometer and criminally negligent treatment of the consequences of this event.
If you have a child in your family, explain to him in advance that if he accidentally breaks a thermometer, no one will scold him for it. Otherwise, your child, fearing punishment for a broken thermometer, will hide its remains somewhere under a bed or closet and will not tell you anything – as a result, your whole family will breathe poisonous mercury vapor for a long time.