From Big Medical Encyclopedia

LEAD (Plumbum, Pb) — chemical element IV of group of a periodic system of D. I. Mendeleyev. In medicine nek-ry connections C. use as pharmaceuticals. The page in large numbers goes for production of means of protection from ionizing radiation (the containers, screens, the rubberized aprons and gloves) used in a radiology, radiobiology and radiology and also accumulators, cable covers, paints, varnishes, tetraethyllead, etc. Lead and its connections, especially organo-lead compounds of a fatty series, have high toxicity and represent considerable professional harm for working in contact with them. Besides, believe that S. is a mutagen (see. Mutagens ). In experiences on a lab. animals its oncogenicity was found, concerning the person S.'s oncogenicity is not established.

S.'s metallurgy has ancient history. Most likely, S.'s smelting was one of the first metallurgical processes known to the person: well remained lead water pipes are taken at excavation of Ancient Rome, coins and medallions from S. are found in Ancient Egyptian burials.

S.'s maintenance in crust makes 1,6*10 - 3  %. It is known apprx. 80 minerals containing S., native S. in the form of the fine grains and scales interspersed in the bearing breed occasionally meets. The most important mineral C. — a galenite (galena, PbS), it meets in all sulfide ores of a hydrothermal origin. In S.'s biosphere is present at a scattered state: in living material find apprx. 5-10_5% (500 mkg/kg) of lead, in sea water from 3*10 - 9 to 40*10 - 9  % (0,03 — 0,4 mkg/l). Underground waters contain 1 — 60 mkg/l of lead, in surface sweet waters of 0,1 — 10 mkg/l. Uncontaminated free air contains about 0,001 mkg! m3 of lead. The discrepancies of abundance of S. which are available in scientific literature in objects of the biosphere are caused not only by natural features of the area, but also extent of its technogenic pollution of S. Sushchestvuyut numerous proofs of gradual increase in concentration of S. in plants and tissues of animals and the person owing to universal environmental pollution of Page. The usual maintenance of S. in vegetables and cereals makes 0,1 — 1,0 mkg! of nonvolatile solid or 2 — 20 mkg/g of ashes, in milk of 5 — 12 mkg!. With food and water of people every day absorbs from 20 mkg and more (on average to 200 mkg) lead, with dusty air — to 100 mkg.

Sequence number of lead 82, atomic weight (weight) 207,2. Natural S. consists of mix of five isotopes — 208, 207, 206, 204 and 202 (traces). Isotopes 206, 207 and 208 are end products of radioactive decay of uranium, actinium and thorium. The most important radioisotope of lead 210R represents long-living (half-life apprx. 20 years) decomposition product radon (see).

Natural S. represents soft, plastic metal of gray-blue color, density 11,336 at 20 °; t°pl 327,4 °, t°kip 1740 °. In diluted to-takh S. it is almost insoluble (this property allows to apply it in production of accumulators). Rather easily S. is dissolved in acetic to - those, saturated with air. At the room temperature of S. is oxidized only from a surface, forming the protective film of oxide (litharge) of PbO protecting it from action to - t and other aggressive environments. In chemical connections C. it is preferential dvukhvalenten, in a tetravalent condition of S. it is unstable. Salts C. share on water soluble (acetate, nitrate and lead chlorate), slightly soluble (chloride and fluoride) and insoluble (sulfate, a carbonate, chromate, phosphate, molybdate and sulfide).

Metal S. is received oxidizing roasting of a galenite (with soakage of air through a heated layer of furnace charge) and the subsequent recovery of oxide C. to lead, to-ry then refined and cleared electrolysis.

During qualitative analysis lead is found in group of sulfides, not soluble in ammonium sulfide (NH 4 ) 2 S. PbS lead sulfide is separated dissolution in warm diluted nitric to - those. In solution lead can be determined a white deposit by training at addition by a chamois to - you and chlorides or a yellow deposit during the processing by iodides, chromates, bichromates. The method of extraction of S. from solution is extended by the dithizon dissolved in chloroform. This method differs in high sensitivity. Quantitative definition of S. on condition of its high content in the studied substrates can be carried out by sedimentation in the form of sulfate and chromate with the subsequent titration by ammonium molybdate (ohm. Titrimetric analysis). The small amounts of S. which are present usually in biol. substrates and objects of the environment, determine by methods of atomic absorption spectroscopy and flameless atomic absorbing spectroscopy (see), polyarografiya (see), etc. Apply a method of neutron activation to simultaneous definition of S. and other elements (see. Activation analysis ).

Biol. and medical value C. is defined by its high toxicity, ability to get into an organism and to collect in it, and also all the growing impact on the person as a result of pollution of the biosphere and broad use in the industry. Pages carry to the poisons operating preferential on nervous, vascular systems and directly on blood. The mechanism of toxic action of S. is explained, apparently, by its ability to block SH groups in molecules of the enzymes participating in synthesis porphyrines (see), regulating synthesis gem (see. Gemoglobin ), etc., napr, porfobilinogensin-Tazy (aminolevulinat-dehydratase; KF 4. 2. 1. 24), ferrokhelataza (a hematin — a ferroliaza; KF 4. 99. 1. 1), etc. Lead is deposited in the basic (to 90%) in a skeleton, is emitted preferential with urine and a stake, in the conditions of high arrival of S. in an organism it is allocated to hl. obr. with urine. The page is found in saliva, a gastric juice, bile, breast milk. Having ability to get through a placental barrier, S. can collect in an organism of a fruit and exert adverse impact on the course of pregnancy and childbirth. To 10% of the lead which got with food and water to an organism it is soaked up in intestines, at steam inhalation and S.'s aerosols its assimilation by an organism by 10 — 20 times to a vdopa, i.e. in this case S. can be absorbed almost completely. Each microgram of lead in 1 m3 of air at long stay in such atmosphere causes S.'s concentration in blood of 1 — 2 mkg! 100 ml. Safe for the person consider daily receipt of 0,2 — 2 mg of lead.

The organism of the people who are not contacting to S. in the conditions of industrial production or near it contains on average 2 mg S. Rol S. in an organism is not clear. Apparently, S. is not biogenic microelement (see). At the same time presence of usual number of S. caused by a natural background is obvious, harmless to an organism. Concerning safety of levels of maintenance of S. in the biosphere caused by technical activity - the person, a consensus is not present. Considerably S.'s number increased in comparison with norm in the environment cause diverse damages of a human body, affecting various fermental systems and being the reason of disturbances proteinaceous, carbohydrate, phosphoric and other types of exchange, and also leading to hypovitaminoses of C and B1.

Drugs of lead

In medical practice as pharmaceuticals use nek-ry inorganic and organic salts C., to-rye appoint only for external use as, being soaked up in went. - kish. a path or respiratory tracts, they show high toxicity.

Drugs C. have practically no the cauterizing and keratolytic effect and only in considerable concentration and on long exposure can cause a nek-swarm irritation of fabrics and mucous membranes.

Local action of drugs C. is characterized knitting and antiseptic by effects. Their knitting action is caused by the fact that ions of Pb 2+ , released at dissociation of connections C., form almost insoluble albuminates with proteins of surface fabrics. The knitting effect of drugs C. is followed by a spasm of small vessels of surrounding fabrics and reduction of secretion of excretory glands that promotes easing of intensity of inflammatory reaction and pain in the field of bruises, small grazes and small wounds. On an antiseptic f-tivnosti drugs C. considerably concede to other antiseptic agents.

Drugs C. in medical practice use in the form of ointments, water solutions (lotions) or plasters for external use. Acetate, water lead, a plaster lead idle time, a difficult lead plaster, ointment diakhilny concern to them lead.

Lead acetate (Plumbi acetas, Plumbum aceticum; joint venture. B), Pb (CH 3 COO) 2 • 3H 2 O, represents transparent colourless crystals with a slight smell of vinegar, sweetish taste, well soluble in mix from 2,5 h water of room temperature and 0,5 h boiled water, in glycerin, it is slightly worse in alcohol, almost not ether-soluble. Lead acetate is used for preparation of ointments or in the form of water solutions (0,25 — 0,5%). Appoint locally as astringent at inflammatory diseases of skin and mucous membranes. In exceptional cases enter inside for obtaining the knitting effect at diseases went. - kish. path. Store in well corked container.

Water lead (Aqua Plumbi; a synonym a lead lotion) — the mix consisting of 2 h solution of the main lead of acetate and 98 h a distilled water; slightly rather turbid liquid with alkalescent reaction.

The acetate C. which is a part of lead water easily decays under the influence of carbon dioxide gas of air therefore lead water is prepared by extempore and immediately place in densely closed bottle from dark glass.

Use locally in the form of lotions and compresses at treatment of bruises, grazes, at nek-ry diseases of skin and mucous membranes.

Plaster lead idle time (Emplastrum Plumbi simplex, Emplastrum diachylon simplex; the synonym a diakhilny plaster) consists of equal parts of oxide C., sunflower-seed oil, lard with addition of water in the quantity necessary for obtaining plastic weight. Apply outwardly at pyoinflammatory diseases of skin, wounds, furuncles, ulcerations of skin and mucous membranes, and also use as a basis for other plasters applied in dermatological and cosmetology practice. Form of release: a plaster in packages. Store in the cool place protected from light.

Difficult lead plaster (Emplastrum Plumbi compositum; the synonym a plaster of colophony) consists of 85 h a simple lead plaster, 10 h rosin and 5 h terebenthene. Indications to appointment generally same, as at use of a simple lead plaster. Unlike a simple lead plaster the nek-eye possesses irritant action and it is used at it is long not healing wounds, bruises, etc. Store in banks from dark glass.

Ointment diakhilny (Unguentum diachylon) consists of 50 h a simple lead plaster and 50 h vaseline. Indications to appointment same, as at use of lead plasters. Store in glass jars from dark glass in the dry, cool and protected from light place.

Professional harm

Poisonings with inorganic compounds of lead. Danger of intoxication of S. is most real in the extracting and metallurgical industry (see. Metallurgy ), in production of lead paints and pigments, accumulators (see. Accumulator production ), at a hardening of metal products in lead bathtubs, in production of crystal, during the soldering (use of lead-bearing solders), during the cutting of the metal products painted by lead paints (Pb minium 3 O 4 etc.), in printing production (see), etc. Under production conditions S. comes to an organism in the form of dust, vapors and an aerosol of hl. obr. through a respiratory organs. S.'s hit through went to an organism. - kish. a path perhaps only at non-compliance a dignity. - a gigabyte. rules (meal in workplaces, pollution of hands and smoking at the same time, etc.). Low protein content, calcium and iron in a diet working in contact with S. can promote increase in absorption of S. in went. - kish. path. In S.'s life comes to an organism generally through went. - kish. a path with the food and water contaminated by Page.

The acute poisonings of S. which before were rather often found on productions are practically not registered and observed now only in living conditions (see. Poisonings, table ).

Characteristic in the past for S.'s intoxication so-called cardinal signs — a lead border (dark gray, sometimes a lilac-tinged and flaky narrow strip on edge of gums) and lead color (earthy-gray complexion) — in connection with radical improvement of the environment on the productions connected with contact with S. lost now the diagnostic value. Chronic lead intoxication (saturnism) is characterized preferential by disturbances in system of blood, defeats of a nervous system and went. - kish. path.

The changes of biochemical indicators of blood caused by S.'s intoxication consist of disturbances of porphyrinic exchange and shifts in red blood (see. Anemia, lead ). In system of porphyrinic exchange (see. Porphyrines ) most early in an organism of the raised S.'s number reacts to receipt aminolevul an inatdegidrataza, activity, the cut in erythrocytes decreases; increase in contents aminolevulinic to - you, protoporphyrin and coproporphyrin in urine, and also aminolevulinic to - you and coproporphyrin in erythrocytes belongs to early reliable and specific indicators of poisoning. Dependence of expressiveness of changes of porphyrinic exchange on extent of influence of lead, contents it in blood and weight of poisoning is established. Shifts in morfol. to a picture of blood — the reticulocytosis, increase in quantity of basphilic and granular erythrocytes — carry to nonspecific indicators of a saturnism, their diagnostic value is small. Anemia at a saturnism belongs to group of hypochromia gipersideremichesky anemias as its characteristic signs are hypochromias» I erythrocytes at increase in content of iron in blood serum (so-called sideroakhrestichesky anemia). In its development an essential role is played by the direct action of S. on erythrocytes leading to reduction of duration of their life.

In professional pathology most often use classification hron. S.'s intoxications, offered Ying volume of occupational health and occupational diseases of the USSR Academy of Medical Sciences and stated below.

Initial form hron. S.'s intoxications the wedge is characterized by absence, signs and is established only on so-called laboratory symptoms of intoxication.

Contents aminolevulinic to - you and coproporphyrin in urine reach 15 mg/g of creatinine and 300 mkg/g of creatinine respectively. S.'s maintenance in blood does not exceed usually 50 mkg / 100 ml, and in urine — 100 mkg/l. The reticulocytosis to 20 — 25 °/00, quantity of basphilic and granular erythrocytes increases to 35%oo-

the Easy form hron. S.'s intoxications the wedge, symptoms is characterized by accession. At easy forms of a saturnism it is diagnosed initial polinevropa-tpya (a so-called vegetative and sensitive form). At the same time vegetative and trophic disturbances prevail: pains, paresthesias, feeling of numbness in extremities, especially at night at rest. Objectively at nevrol. inspection discoloration of skin of fingers of hands (slight cyanosis or pallor of skin), a hyperhidrosis, a hypothermia, symmetric distal disturbances of sensitivity, at first in the form of hyperesthesias, and then hypesthesias, a hypomyotonia, block of a dermographism, lability of the ABP, a tendency to bradycardia can be noted. Decrease in excitability of olfactory, flavoring and visual analyzers is characteristic. Unsharp expressiveness and nespetsifich-nost nevrol. symptoms at easy forms of a saturnism are demanded for their identification of use of a number of electrophysiologic methods (an electromyography, rate of propagation of an impulse on a peripheral nerve, etc.).

Changes in went. - kish. a path at an easy form hron. S.'s intoxications are expressed in disturbance of gastric secretion (its increase or decrease), processes of absorption in intestines, motility of intestines with development of a diskineti-chesky syndrome. Functional disturbances of a liver are possible.

Disturbances of biochemical indicators at this form hron. S.'s intoxications are more expressed: contents aminolevulinic to - you and coproporphyrin in urine can increase to 25 mg/g of creatinine and 500 mkg/g of creatinine respectively, S.'s maintenance in blood, as a rule, does not exceed 80 mkg / 100 ml, and in urine reaches 150 mkg/l. A reticulocytosis to 40 ‰, quantity of erythrocytes with basophilic stippling to 60 ‰. Perhaps nek-swarm decrease in a hemoglobin content.

The expressed form hron. S.'s intoxications it is characterized by development of the expressed polyneuropathy, at the same time along with sensitive frustration motive can be observed, astenovegetativny disturbances accrue.

At the expressed form hron. S.'s intoxications the so-called lead colica is often observed, edges it is shown by colicy pains in a stomach, the obstipation (its duration can reach 10 — 14 days) which is not giving in to action of purgatives, raising of the ABP it is frequent in combination with bradycardia, fervescence, and also a moderate leukocytosis, dark red color of urine (due to allocation of a large amount of porphyrines). Sometimes the lead colica is followed by defeat of uric ways and proceeds as renal colic (see. Nephrolithiasis ). It is necessary to consider a possibility of development of the atypical, erased forms of a lead colica proceeding wavy for a long time (up to 3 — 4 months) and characterized by less bright a wedge, and a lab. symptomatology. For the expressed form hron. intoxications development of an anemic syndrome with decrease in level of hemoglobin lower than 130 g is characteristic! l at men and 120 g! l at women.

At long contact with S. note defeat of certain sites of bones and joints: emergence in metaphyses of long tubular bones of the homogeneous, evenly intensive blackouts which are sharply delimited from a diaphysis of a bone. Contours of blackout smooth. Intensity and width of blackouts (so-called lead strips) depends on the quantity of the absorbed Village. Changes in a bone tissue at S.'s intoxication are not followed by destructive processes, changes of a periosteum are absent. Most often tibial and fibular bones, a femur, humeral, elbow, beam bones, edges are surprised.

Complexity of diagnosis is that similar rentgenol. the picture is observed also at nek-ry other diseases, in particular at other hron. intoxications, syphilis (see), rickets (see), to a scurvy (see). Therefore at observation of the specified changes on the roentgenogram detailed acquaintance with given the anamnesis, working conditions and life for the purpose of establishment of the fact of impact of S. on an organism is necessary.

Biochemical disturbances at the expressed form hron. S.'s intoxications are clearest. Contents aminolevulinic to - you and coproporphyrin in urine make more than 25 mg/g of creatinine and more than 500 mkg! of creatinine. S.'s concentration in blood reaches 80 mkg! 100 ml and above, and in urine more than 150 mkg! l. The reticulocytosis more than 40%0, and quantity of oh-zofilno-granular erythrocytes exceeds 60%00.

During the definition of a form hron. S.'s intoxications need to be meant that existence of all signs characteristic of any form, not necessarily. Sometimes defeat of one bodies and systems can correspond easy, and others — the expressed form hron. intoxications. In such cases the diagnosis is established on the basis of the most expressed syndromes.

Signs of impact of S. on an organism reveal at periodic medical examinations (see. Medical examination ), the diagnosis of intoxication can be established only after inspection in specialized to lay down. establishment.

The most effective therapeutic remedies at hron. S.'s poisonings are complexons (see), the strong, not dissociating, low-toxic complexes forming from S., to-rye are quickly brought out of an organism through kidneys. Most often use 10% solution of tetatsina-calcium, to-ry enter intravenously 1 — 2 time a day within 2 — 3 days (20 ml into 500 ml of 5% of solution of glucose). Apply also Pentacinum (especially at a lead colica). Both drugs have high secretory activity concerning lead and are capable to stop quickly one of the heaviest manifestations of a saturnism — a lead colica. Drugs are used intravenously. Pentacinum is entered in isotonic solution of sodium chloride or into 5% solution of glucose on 200 ml of 1 — 2 time a day. Daily dose of 2,0 — 4,0 g. The course of treatment consists of 3-day cycles with 3 — 5-day breaks between cycles. For treatment of intoxications of S. widely use D-Penicillaminum in a daily dose of 600 — 900 mg \it accept in 30 min. after food.

At treatment hron. intoxications of S. which is followed nevrol. frustration, widely use vitamins of group B, ascorbic to - that, the drugs possessing spasmolytic action, ganglio-blockers, physiotherapeutic methods of treatment.

The most important preventive action is S.'s replacement and its connections in the corresponding productions with other, non-toxic substances.

The maximum mechanization of operations on processing of lead-bearing materials, sealing of sources of a pylevydeleniye of S., moistening of the raising dust materials, and also the equipment of rational is necessary ventilation (see), power tool cleaning of workrooms from dust. In dusty rooms — work in respirators (see. Respirators ), the industrial filtering or hose gas masks (see) with forced feed of a pure air.

During the work with S. and its connections strict observance of measures personal is necessary hygiene (see) and prevention (special food allowances, preventive receptions of complexons, etc.), meal and smoking in workplaces are categorically contraindicated. An essential role in prevention of intoxication of S. is played preliminary (at revenues to work) and periodic medical examinations.

Issues of examination of working capacity at a saturnism are resolved depending on expressiveness of poisoning. At an initial form of intoxication temporary transfer for work out of contact with S. for a period of 1 — 2 month is necessary. Further such patients can be returned for former work (on condition of full normalization of indicators of porphyrinic exchange). In case of a recurrence of intoxication complete cessation of contact with Page is necessary. At the expressed forms of intoxication working shall be surely discharged of work with S. even in case of total disappearance of signs of a saturnism as a result of treatment.

The persons which did not reach 18 years are not allowed to work with S.; work of women at the enterprises for processing of lead-bearing ores or materials is limited or completely prohibited.

Maximum allowable concentration for lead and its inorganic compounds in air of a working zone of 0,01 mg! m3.

Poisonings organic to connections and lead. The most known organic compound C. is tetraethyllead, to-ry is used as additive to different types of gasolines.

Tetraethyllead gets into an organism through respiratory tracts and is easily soaked up through the unimpaired skin and from went. - kish. path. In an organism tetraethyllead metabolizes with formation of trietil-lead, breaking oxidizing processes in system carboxymanholes and phosphorylations; tetraethyllead and ions of lead it is long circulate in an organism, slowly removed with urine and a stake.

The contact working with tetraethyllead is possible on productions where it is synthesized, during the receiving, transportation and storage of an ethyl fluid, leaded gasoline, at operation and repair of internal combustion engines.

Depending on intensity, and duration of influence of tetraethyllead can arise acute or hron. poisonings. In the USSR in connection with considerable improvement of working conditions acute intoxications are liquidated, and chronic are observed seldom.

At acute poisoning with tetraethyllead the eclipse period of action from several hours to several days is noted. Victims complain of a headache, dizziness, weakness, an uneasy dream, the strengthened salivation, nausea, gripping pains to breasts, a joint pain. In hard cases there is a sharp psychomotor excitement, fear of death; the collapse is possible.

At acute poisoning with tetraethyllead mental disorders arise later 4 — 8 days, in hard cases — in 10 — 12 hours Klin, the picture depends on weight of poisoning. The first symptoms of Acute intoxication are shown in a look asthenic syndrome (see), feature to-rogo are the expressed vegetative frustration — bradycardia, hypotension, a hypothermia, the strengthened salivation and sharp perspiration. The suppressed mood, sensation of fear, alarms, sometimes euphoria are characteristic; unpleasant feelings in a breast, a stomach, hand and legs pains, a headache with feeling «swellings, transfusions», amplifying at the movement; sleep disorders in the form of difficulty of backfilling, bright fantastic dreams of frightening character. The adynamy at early stages can already be followed such nevrol. symptoms, as an ataxic gate (see), a dysarthtia (see), a tremor of fingers of hands, a gipomimichnost and constraint. Sometimes there are vestibular disturbances, frustration of a body scheme (see). Against the background of an adynamy quite often arise to a hallucination, a thicket gipnagogichesky (see. Hallucinations ). During backfilling patients have a feeling of pushes and hiting at to a body, the frightening visual hallucinations. Visual hallucinations are possible also in a condition of wakefulness. Patients see smoke, a web before eyes; the feeling of a foreign matter in a mouth is typical (a hair, thread, a wire, a pin, etc.).

Acute psychoses at poisoning with tetraethyllead are shown more often in the form of delirious and delirious and amental syndromes (see. Amental syndrome, Delirious syndrome), is more rare — catatonic, gebefrenokatatonichesky (see. Catatonic syndrome ). Feature of a delirium is the deep water of disturbance of consciousness, the sharp psychomotor excitement amplifying in parallel with weight of intoxication, visual, auditory, olfactory and tactile hallucinations. Development of a hyperkinetic delirium is possible. Stupefaction is followed various nevrol. symptoms: the tolchkoobrazny twitchings of a body and separate muscles reminding myoclonic spasms then develop horeo-and the atetozopodobny movements of extremities, the heads, trunks. Not stopping movements of extremities — swimming, shuffle by fingers of hands, the movements reminding made during the catching of insects and during the winding of threads, etc. are sometimes observed for hours. Sharp vegetative and vegetative and trophic disturbances are characteristic. The course of psychoses can be fulminant, galloping with a lethal outcome in 2 — 6 days. At the same time the delirium is replaced by a sopor and further a coma (see. Delirium acutum ). More often psychosis gets a long current with the subsequent shift by the phenomena of an adynamy, against the background of a cut the nonsense with the uniform maintenance of the crazy ideas can develop, characterologic changes with dominance of lines of excitability appear.

Hron. poisoning with tetraethyllead is characterized, indistinct symptomatology. There is a resistant adynamy with the senesthopathias and vegetative frustration which are followed incremental nevrol. symptoms in the form of a maskoob-difference of the person, a dysarthtia, a tremor of fingers of hands, decrease in memory; psychoses have long character, causing permanent and deep disturbances of mentality.

Treatment at poisoning with tetraethyllead shall be complex, including disintoxication and fortifying therapy. Use of tranquilizers and nootropic means is possible. At psychoses apply neuroleptics.

At all forms of poisonings with tetraethyllead morphine, Chlorali hydras, bromides are contraindicated.

After the postponed poisoning with tetraethyllead resistant defects of mentality, intellectual degradation, falloff or full disability can be observed.

Prevention of poisonings with tetraethyllead includes full sealing of technological process with distance steering in production of tetraethyllead and at its use, the device of effective ventilation, finishing of production rooms the materials which are not occluding tetraethyllead; constant control of air of a working zone, overalls and skin; daily shift and decontamination of overalls, linen and footwear, daily passing of the sanitary inspection room; in necessary cases use of a gas mask of brand A.

Systematically periodic medical examinations shall be performed (see) for identification of initial forms of poisoning and transfer into the work which is not connected with tetraethyllead.

Use of female labor on the productions connected with tetraethyllead is forbidden. Working at this factory have the shortened working hours, additional issue, preventive foods and other privileges.

Maximum allowable concentration for tetraethyllead in air of a working zone 0,005 mg1m.

Lead in the medicolegal relation

At a research of a corpse of the person who died from poisoning with inorganic compounds C. is noted by swelling and reddening of the mucous membrane of a gullet and stomach covered with a white or gray plaque; on gingivas it is possible to find a dark border. The mucous membrane of intestines is inflamed and painted in dark color. In kidneys — the phenomena of irritation and dystrophic changes of cells of tubules of nephrons, adjournment of salts uric to - you. Court. - chemical definition of inorganic compounds C. is made by a fractional method in a mineralizata of hinge plates of fabrics. The mineralization is carried out sulfuric and nitric to-tami. The formed deposit of lead sulfate is dissolved in a certain volume of solution of ammonium acetate and extracted chloroform in the form of a ditizonat of lead. If at fabrics there is S., extract is painted in pink or red color. If definition was carried out strictly quantitatively, then after a fotometrirovaniye of extract it is possible to define precisely S.'s maintenance in the taken hinge plate of fabric. Test-sensitivity of 0,02 mg of lead in 100 g. S. which is contained normal in parenchymatous bodies is not defined by a fractional method.

Morfol. changes at acute poisoning with tetraethyllead are characterized by defeat of neurons of talamo-hypothalamic area and a cerebral cortex, and also hemodynamic frustration in internals; at hron. poisonings note full death of separate neurons. Tetraethyllead circulates in blood in the form of the whole molecule during 2 — 3 days, in a corpse quickly decays. In this regard it is not recommended to postpone opening, and the taken material needs to be subjected quickly court. - chemical examination. Court. - chemical definition of organic compounds C. is based on their oxidation to inorganic compounds C. and definition of the last (see above).

Bibliography: Arkhipova O. G., Zorin L. A. and With about r to and N and N. S. Complexons in clinic of occupational diseases, page 25, M., 1975; Bathhouse attendants V. M., Korolenko Ts. P. and Korolenko of T. A. Intoksikatsionnye psychoses, page 93, M., 1968; Careful R. V. Forensic medical examination of poisonings with technical liquids, M., 1977; Harmful substances in the industry, under the editorship of N. V. Lazarev and I. D. Gadaskina, t. 3, page 461, 1977; Hygienic criteria of state of environment, 3. Lead, Geneva, WHO, 1980; Digoyeva M. D. and Berezov T. T. Some biochemical, immunological and morphological changes of system of blood at the people who are in continuous contact with lead salts, Vopr. medical chemical, t. 27, century 2, page 223, 1981, bibliogr.; Korolenko Ts. P. and B. N. K Piven to a question of mental disturbances at chronic lead intoxication, Zhurn. neuropath, and psikhiat., t. 71, century 4, page 589, 1971; Krylova A. H. A research of biological material on «metal» poisons by a fractional method, page 28, M., 1975; Mashkovsky M. D. Pharmaceuticals, p. 4, page 308, p. 2, page 356, M., 1977; K. P. Rentgenologiya's Prickly lettuces of occupational diseases and intoxications, page 106, M., 1961; Acute management at acute poisonings, under the editorship of S. N. Golikov, page 124, M., 1977; P about r t of N about in A. A. Klinik of acute tetraethyllead psychosis, M., 1956; R both in and to and N and R. L. Epileptic and epileptiform manifestations at lead intoxication, the Works Center, in-that psikhiat., t. 1, page 230, M., 1940; Shvaykova M. D. Toxicological chemistry, M., 1975.

B. A. Knizhnikov; R. V. Berezhnaya, A. F. Rubtsov (court.), E. A. Grigoryan (rents.), E. N. Marchenko (poisoning with organic compounds of lead), D. N. Samoylov (pharm.), N. S. Sorkin (poisoning with inorganic compounds of lead), M. A, it is civil (psikhiat.).