Mercury intoxication.
Conditions for the occurrence of mercury intoxication.
Mercury is a liquid metal that easily evaporates at room temperature.
temperature. Professional mercury poisoning is possible in dentists during the
preparation of amalgam for dental fillings, in the production of mirrors,
fluorescent lighting lamps, measuring
devices. Poisoning occurs when non-compliance
safety regulations or malfunction of technological equipment.
Ways of entry of mercury into the body.
Mercury usually enters the body through the respiratory system and
digestion. The most dangerous is inhalation of vapors or aerosols of metallic
mercury and its compounds. The oral route of intoxication is possible when
soluble mercury compounds enter the mouth. Metallic mercury is of little danger,
since it is not absorbed in the digestive tract.
The specificity of the accumulation of mercury in tissues.
After inhalation of mercury vapor, it begins to circulate in
blood, deposited in the liver, kidneys, in the brain (pituitary gland, cerebellum).
Most of the soluble chemical compounds of mercury taken by mouth are very
dangerous poisons. As a result of absorption in the intestine, they cause severe
damage, primarily to the liver. Some of the mercury is deposited in bones, liver,
and lungs. Depositing, leaving the depot and then re-entering
deposition promotes long-term circulation of mercury, chronic damage to internal
organs, microcirculatory vascular bed, even after a single intake of poison into the
body.
Removal of mercury from the body. Metallic mercury after oral ingestion into the
digestive tract is usually excreted unchanged in the feces. Mercury compounds
circulating in the blood and located in the depot are gradually excreted from the
body through the biliary system and intestines, as well as through the urinary
tract, salivary, sweat glands. Mercury ions can be excreted in breast milk.
Pathogenetic mechanisms of mercury intoxication.
Mercury is a classic thiol poison - it blocks the sulfhydryl SH-groups of proteins.
Interacting with sulfhydryl groups of proteins, ions
mercury disrupts many vital metabolic processes. As a result of this, first of all,
functional, and then degenerative changes occur, mainly in the central nervous
system. The myelin sheaths of the nerve trunks are affected. There are various
pathological changes in the parenchymal organs - liver, kidneys. Blockade of renal
carbonic anhydrase by mercury ions causes polyuria. In the last century, diuretics
containing mercury were produced and widely used.
The main clinical syndromes.
There are practically no acute mercury poisoning at work
meet. They are manifested by neurotoxicosis in the form of intense headache,
nausea, vomiting, severe weakness, adynamia. The affected develop a metallic
taste in the mouth, drooling, abdominal pain, sometimes bloody diarrhea, and
polyuria. Ulcerative stomatitis and gingivitis are typical.
Chronic intoxication is characteristic of persons who have been in contact with
mercury and its compounds under industrial conditions for many years. Chronic
mercury poisoning of mild degree is characterized by the appearance of
vegetative-vascular dystonia with neurosis-like syndrome in the form of
pathological "embarrassment", emotional instability, vasomotor hyperreactivity.
In sick
there are sensations of a metallic taste in the mouth, memory decreases, physical
capacity for work decreases, sleep is disturbed, "causeless" attacks of severe
headaches occur. Possible clinical manifestations of intoxication in the form of
mercury gingivitis with a purple border on the gums, gastric dyspepsia, unstable
blood pressure, tachycardia, small-amplitude tremor
fingertips.
Chronic mercury intoxication of moderate degree occurs
with prolonged contact with mercury aerosols, the concentration of which in the
air is 3-4 times higher than the maximum permissible level. It is characterized by
organic disorders in the central nervous system with pronounced manifestations
of mercury erethism.
Mercury erethism is accompanied by unusual behavioral reactions in the form of
extreme shyness, embarrassment, strong emotional excitement with palpitations,
redness of the face, sweating even in a familiar environment and among familiar
people.
A complex asymmetric extrapyramidal, large-sweeping tremor (flapping) appears
against the background of a small-amplitude asymmetric functional tremor. A
sensitive form of polyneuropathy occurs. Excretion of mercury with saliva causes
gingivitis with an intense purple border on the gums, stomatitis. Clinical and
biochemical signs of toxic hepatitis are recorded. According to the results of
objective, ECG, EchoCG studies, myocardial dystrophy is revealed. In the general
analysis of blood, a tendency to eosinophilia is revealed.
Chronic severe mercury poisoning manifests itself
toxic encephalopathy, persistent organic changes in the nervous system. Mercury
erethism reaches extreme severity.
Extrapyramidal coarse tremor becomes generalized.
Diagnostics
Diagnostic criteria for mercury intoxication:
• Professional itinerary certifying long-term
contact during production with mercury compounds.
• Clinical manifestations of mercury erythism.
• The presence of complex mercury intentional tremor in combination with
functional tremor.
• Identification of high levels of mercury in the blood, urine.
Treatment The following groups of drugs are used to intensively remove mercury
from the body:
• etiotropic therapy with unitiol - 5% solution, 5 ml intramuscularly 1 time per day
for 5 days. After a break of 3-5 days with continued excretion of mercury in the
urine, the treatment cycle is repeated. Instead of unitiol, succimer can be used
parenterally at 0.3-0.5 daily for 5 days;
• detoxification therapy with forcing diuresis: intravenous drip of hemodez,
rheopolyglucin, Ringer's solution, 5% glucose up to 500 ml per day in combination
with 40 mg of furosemide for 3 consecutive days;
• elimination of dysmetabolic shifts: balanced
complex multivitamin preparations, Essentiale-forte according to
2 capsules 3 times a day for 30 days;
• means that improve the metabolism and blood supply to the brain: aminalon,
piracetam, stugerone, cinarizine.
• Restoration of adaptive reactivity: minimum (adaptogenic) dosages of tinctures
of ginseng, Chinese magnolia vine ..
• normalization of sleep and correction of behavioral disorders: valocordin,
corvalol, valosedan;
• fortifying treatment: hydrogen sulfide, coniferous and sea baths, UFO, exercise
therapy, psychotherapy;
• Spa treatment
Examination of working capacity.
With a mild degree of poisoning, the affected need to be temporarily transferred
to work without contact with mercury and other toxic substances until
technological violations at the original workplace are eliminated. Moderate
clinical manifestations of chronic intoxication are indications for excluding further
professional contact with mercury. In such cases, when transferring to another
job of a lower qualification, a third group of disability is established until a new
professional qualification is obtained, which is equivalent to the initial one. In the
event of severe intoxication with symptoms of encephalopathy, patients are
disabled - invalids of groups 2 and 1. Together with the definition of the group of
disability, the degree of loss of professional ability to work as a percentage is
established, depending on the severity of the clinical manifestations of mercury
erethism. Individual rehabilitation programs are being developed for disabled
people with the aim of partially or completely restoring the lost ability to work.
Prevention.
In order to prevent mercury intoxication in industrial conditions, a number of
special technological and hygienic measures are used: maintaining a sufficiently
low temperature in working rooms (no higher than 1 (use of
special dense fabric; effective ventilation, etc.)
Periodic medical examinations should not be performed
less often once every 12 months in direct contact with metallic mercury and once
every 24 months when working with equipment and devices containing mercury.
When identifying individuals with initial symptoms of mercury intoxication, as
well as when detecting increased
the content of mercury in the urine, they undergo preventive rehabilitation
treatment in a sanatorium-preventorium.