Lead poisoning - SpeedyLook encyclopedia

The lead poisoning is the name of the Maladie correspondent with an acute or chronic intoxication by the Plomb.

General information on the disease

The induced lead poisoning of the disorders which, according to their seriousness and the moment of, will be reversible (Anémie, digestive disorders,…) or irreversible (attack of the nervous system, encephalopathy,…).
C' is a disease which can affect all the Mammifère S and the Oiseau X (avian lead poisoning); for other species one will rather speak about lead intoxication or intoxication by lead
Chez the man, the legal threshold of Danger is in France of 100 µg of lead per liter of blood, but of many authors estimate that effects on the brain and cognition appear before this rate or whatever the amount. The young child, the fetus and the embryo are much more sensitive there than the adult.

Part of the lead absorptive by ingestion or inhalation is excrêté in the urine and the excrements, the remainder accumulates relatively durably in the organization, primarily in the Os; 80 to 95% of absorptive lead is fixed in the bones in there substituent at the Calcium. In the bone, lead has a average Demi-vie from 20 to 25 years. It is also stored in the Foie, the Rein, the Cerveau. where it causes serious and irreversible effects on the organization, of which Backwardness in the child, hypertension, turbid neuromoteurs even Paralysie, sterility, Cancer and dead.

The individuals are more or less predisposed and sensitive to lead poisoning; according to the age and the exposure time, according to certain genetic characteristics and if they are deprived of certain nutrients and trace elements (calcium in particular).

Lead poisoning is not transmissible with the direction infectious of the term, but an young woman who was significantly contaminated by lead; possibly years before (up to 20 years earlier), when it was young girl, teenager or adult young person) transmits the disease to its child in utero , lead crossing the placental barrier easily.

La toxicity of lead is known since antiquity. Evidence of this disease exists for antiquity since the Bronze Age.

Synonyms:

“ lead Imprégnation ” is synonymous with lead poisoning if this impregnation results in symptoms of the disease or can induce them in the long term.
“ Coliques of lead ” indicates the painful abdominal symptoms (Colique S) of acute lead poisoning.
“ Maladie of the painters ” is the name of a symptom noted at the time or the white lead of lead and other paintings with lead were very much used.
“ Pica ” is the name of a behavior which consists in the child carrying what it finds with the mouth. It is often associated with lead poisoning in the child, and more rarely in the adult (one then speaks about “pica-like” ). It should be noted that the animals (ex cows in the cattle sheds) can also poison themselves seriously, even mortally by licking old paintings with lead, probably because of their also sweetened taste.

Origin and causes of the disease

With the difference of the majority of metals, lead does not have any role known in the human organism, nor at other animal species or vegetable. It seems toxic at the cellular level, whatever its concentration.

Origin of the toxicity of lead: It especially seems to come from its capacity to circulate in the food chains and the organizations, in “mimant” the behavior of other vital metals, of which mainly calcium, iron and zinc.
Le lead replaces in various bodies and thus interacts with the production of proteins and molecules implying these three metals. Lead slows down or prevents thus vital or secondary processes; it inhibits the production of some Enzyme S and the transport of oxygen by blood in particular.
La majority of the primary symptoms of lead poisoning rises owing to the fact that lead interferes negatively with a essential Enzyme, Delta-aminolevulinic acid dehydratase (ALAD). The ALAD is a protein containing a molecular bridge depend on zinc. It is vital for the biosynthesis of the Hème, cofactor of the production of the Hemoglobine.
Le lead inhibits also another vital enzyme (Ferrochelatase) which Catalyze the meeting of the [[protoporphyrin]] IX and of the ion Fe 2+ which forms the Hème.

Possible confusions

Lead poisoning does not have specific symptoms. It for this reason is badly detected, and often very tardily after being confused with others turbid benign (food poisoning, headaches, tire, alcoholism, anomalies congenital, turbid of behavior.).

A genetic mutation of the ALAD causes a rather rare disease (the Porphyrie) which can be confused with the lead poisoning (and that the film The Madness off King George illustrated), but which can be differentiated by the fact about it that lead produces an anemia, which is not the case of the porphyrie.

Measure and thresholds of toxicity

Lead traces are detectable in the blood of all the individuals. the CDC of the United States, the WHO and the majority of the countries of the European Union have a limiting value of 10 µg/dL of blood because the Plombémie (lead rate in blood) is the Indicateur most commonly used in the world for reasons of convenience, but it is incomplete. Other indicators thus are sometimes used:

the plombemy indicates a recent contamination.
the measurement of lead in the teeth (Tooth baby if necessary), in the bone informs about an old contamination.
the analysis of lead in the Phanère S (Hair, Nail S, Hair S) informs about a fairly recent contamination (previous months, year).
the analysis of lead in the air and the environment (dust, paintings, water, food) is also an indicator complementary to exposure.

It is possible retrospectively to detect cases of lead poisoning via the study of lead contents of corpses or skeletons of people or animals dead (possibly it has been several centuries or millenia if their remainders are well preserved).

Thresholds of toxicity: They are very discussed since the progress made in toxicology; plombémies formerly considered as “sure” correspond torates now considered as dangerous Blood lead levels ounce considered safe are now considered hazardous, with No known threshold. and of many toxicologists estimate that there are no thresholds in on this side which lead can be really regarded as without danger, in particular for the brain. However to change the legal Norme (proposal studied by WHO) would have economic implications such that they still seem to make obstacle with this idea. That would have also complex legal implications concerning the application of the Principe pollutant-payer and the treatment of the “occupational diseases” .

average Exposure of the population: the many human ones live today with a plombemy much higher than what it was with prehistory, with rates likely to present health issues and of development, to even interfere with the operation of the brain
On lack of data for many countries known as " pauvres" , but the average plombemy in the rich countries exceeds generally 10 Microgramme S by Décilitre, or 100 Pb (left per billion). It is not rare to find people exposed whose plombemy exceeds 200 Pb whereas the majority of the symptoms appear with approximately of 100 Pb and that the measurable effects on the behavior and cognition (with loss of IQ) of the children appear with amounts much lower than these levels

Tracing : measurements isotopic S of the lead found in the Blood, the Os, or the Environnement make it possible - under certain conditions - to determine and trace the origin of it (the lead of the gasoline has for example an isotopic signature very different from the lead of hunting, or that used in the batteries).

Space and temporal distribution of lead poisoning

Lead poisoning today

There remains a problem of Public health, including in the rich countries where the majority of the serious cases and located lead poisoning concerns children of less than twelve years, alive in zones exposed to lead of origin industrial or alive in an old habitat, even unhealthy where paintings with lead are accessible. Elsewhere the situation is badly known.
Nowadays, acute lead poisoning is most frequent in the child and often induced by the ingestion of lead in the form of particle fines or scales of painting to lead (Céruse or lead hydroxycarbonate). The origin of these cases is generally an exposure in the old habitat to the lead white lead, painting very much used until its prohibition in 1948. Painting is introduced directly or in the form of dust produced during its degradation during time or at the time of work (roughs-casting, scraping, brushing, sandpapering.). In France, a collective expertise on INSERM estimated into 1999 that 85.000 children from 1 to 6 years were still victims of this type of lead poisoning.
Plus seldom, one notes intoxications by the water contaminated by old lead pipings (in particular in the areas where water is naturally acid).
L' inhalation is locally (near the factories and of sites polluted by lead) a very important factor of contamination (For example in the north of France, the closing of the Northern factory Metaleurop resulted in a fast fall of the Plombémie in the children of the peripheral zones, without however making disappear the traces from a basic pollution).
certains food cultivated on grounds polluted by lead, meats of animals having introduced plants rich in lead or soiled, and some Champignon S are also sources of food lead poisoning of origin. In particular, the consumers of Gibier of water killed in certain areas very driven out and strongly contaminated by the Grenaille of lead of hunting are exposed at the high risk of lead poisoning. more rarely, the side of meat located close to the entry of the ball in the flesh of a big game (roe-deer, stag, wild boar.) killed by lead bullet could also be a source of intoxication. It is in any case a shown source of avian Saturnisme at the Condor of California.

Occurrence, prevalence

Except intoxications professional and/or related to the old habitat, the prevalence of lead poisoning remains badly known ; Except in the situations where the risk is known, the disease indeed only seldom is detected by the Occupational medicine. In the same way for the school Medicine (when it exists), the rural medicine or of city and emergency medicine. One can see several reasons there:

not-specificity of the symptoms which for the majority can be confused with a minor problem, banal and specific,
the plombemy is seldom proposed in preventive medicine (cf cost + possible non-repayment by the social security?)
symptoms of intoxications being able to appear several years, even several decades after the exposure ( “lead poisoning of the menopause” ), which make that the doctor does not evoke lead spontaneously if the patient does not report indices of last exposure.
absence of simple and immediate test reliable (the plombemy traces only one recent exposure, only the analysis of the bone informs about the exposure about the long run),
gaps in the training of the doctors,
sociopsychologic reasons; to speak about a poison suitable for induce mental disorders is not easy for the doctor. (As example, all great maternities could have an apparatus Xray-fluorescence allowing a proximate analysis of each Umbilical cord during each childbirth. This would make it possible to measure the total prevalence of lead poisoning in the population, to identify the populations at risk and to warn the parents in the event of problem and to recommend a food supervised for the first years of the child, but perhaps. Ideally, a plombemy should be recommended at the beginning of pregnancy, which is very seldom the case, certain doctors evoking of the reasons ethical S, including the risk to disturb the serenity of the mother lasting the pregnancy in the event of high plombemy.

Primary sources of poisoning

Risk and danger…
La original source (the Danger) can be:

of lead-metal (ex: jewel containing of lead, in direct contact with the Skin, lead shot introduced and trapped in the appendix)
of molecular lead (ex: lead vapors; lead is sublimated out of lead vapor at a temperature unusually low at metals)
salts of lead (e.g.: pigments made up of lead oxides)

The Risque is that this lead is absorbed by the organization, and particularly by the fetus, embryo or young child.

Sources of lead :
elles are multiple and vary according to the countries and the contexts (times, places, behaviors at the risk, age.) ; They are in particular

- inhalation of air polluted by lead (industrial pollution, contaminated vapors, dust or smoke, sandpapering of old paintings, leaded gasoline, confined atmosphere of a shooting range…)

- ingestion of food or water contaminated by lead (acid water having corroded of the lead pipes, the weldings containing of lead, or the brass taps or elements of plumbing (container of lead). Ingestion of animals or plants contaminated by a polluted environment, food contaminated by illegal pesticides (Arsenate of lead, etc). Some particular cases concern children or adults who carry readily to the mouth of the objects at the risk (tin soldiers or objects of lead, pencils of artist with black lead). There were some cases of Fraude S where for example of the forgery Paprika had been dyed by lead salts (minium).

- percutaneous penetration, become rare, but possible (cases of ointments and kohls contaminated, toys or jewels out of lead, material containing of lead or painted with pigments with lead).

Principal ways of poisoning :
Rappel preliminary: In the mammals, in all the cases, a intergénérationnelle contamination can be done of the mother to the fetus In utero or via the Allaitement. (In the bird, the avian lead poisoning of the mother can also influence the survival and the capacities of chick).

La first way remains, seems it, the direct ingestion of particles (painting) to lead or of ground and contaminated dust. The young children tend also to suck the painting of bars or window frame, or can sometimes be poisoned while carrying their fingers with the mouth after having touched the lead plates used for the sealing of roofs, gutters or Chéneau X around window frame (or other elements accessible from architecture). Since the end of the XXe century, in a growing number of country, and the majority of the American States and of Europe, the owners, hirers out and/or salesmen of old houses must with their expenses make a diagnosis, and inform the potential residents of the danger.
Les children is sometimes contaminated by a chronic exposure to particles of lead involuntarily brought back to the house by parents working in the metallurgy of lead, the batteries or plumbing (this lead is brought back on the hair, the skin and clothing and shoes). Thus for example at the time of an American northern study, 75% of 16 children of workers exposed to lead presented a plombemy definitely higher than that of the other children of their district (on average 22.4µg/dL against 9.8 µg/dL, p=.049). Another study related to 50 6 year old older children (31 children of parents exposed to lead in the sector of the building, and 19 case-witnesses, children of nonexposed parents); the children of exposed workers were 5 times more to have a plombemy considered to be excessive (25.8% compared with 5.3% for the pilot cases). Another study related to 18 children (of less than 7 years) of repairers of radiators car (weldings containing of lead, and radiators possibly contaminated by the lead of the gasoline); all the children exceeded the threshold criticizes of 10 µg/dL.
Des intoxications of children is also regularly noted following use of Jouet S out of lead, and of imitation jewelleries or decorative objects related to the skin or that the children can carry to the mouth. Idem for toys painted with a painting with lead.
L' food remains a basic of intakes lead, generally weak source, but with certain food more at the risk (Champignon S capable of strongly bioconcentrer and bioaccumuler lead, as also other species do it of which the Moule S, Huitre S, others Coquillage S and Poisson S or Mammifère S Carnivore S. the vegetables having pushed on polluted grounds, drawn waterfowl to lead or having lived in a Wetland for a long time driven out, i.e. polluted by, and moindrement the game lead shot drawn with ball from lead are other food sources of lead which can be punctually factor of lead poisoning.
L' air is a source locally important. The average plombemy clearly declined in the decades which followed the prohibition of lead tétra-éthyl in the gasoline, but certain countries prohibited it only tardily or did not prohibit it yet (Nigeria, Saudi Arabia, exceptions for the overseas territories for France.). In the areas industrial, near old incinerators and not put at the standards, certain mining sites or iron-foundries, the vapor inhalation and lead microparticles are a major source of lead not to be underestimated.
L' water of the drinking water distribution network, where it is naturally Acide or neutral, can bring a considerable quantity of lead. The EU imposed the progressive abolition of all lead pipings. The lead dissolved in water can come from the pipes, but also from the Soudure S and accessories in Laiton of bad quality, rich in lead slowly water soluble. In the zones at the risk, it is recommended to make run the water which stagnated during the night in the pipes before drinking it or to use it for cooking.
Certains cosmetic imported such as the traditional kohls of the Middle East, of India, of Pakistan, and certain areas of Africa cause also intoxication, in particular of children (certain kohls traditionally considered to protect the eyes of various diseases contain up to lead 83%). A study having carried on 538 older little girls from 6 to 12 years showed that kohl caused an increase in the plombemy of the young girls. Another study, carried on 175 children Indian Pakistani and 8 months old S at 6 years living to the Pakistan; those which were treated with traditional kohl presented tripled and excessive average plombemy (12.9 µg/dL against 4.3 µg/dL for the other children not having used this cosmetic).
Des potteries cooked with enamels with lead, tins of bad quality or traditional teapots welded with lead frequently was of the proven sources of intoxication, having justified various medical alarms and withdrawals of sale.

The exposure to lead-metal related to the ingestion of small objects (shot of hunting, ballasts of fishing) is not very famous to lead to a raised plombemy, but some exceptions are known; when lead stagnates in the digestive tract and in particular in the appendix where there can remain trapped years, which is not exceptional in the large waterfowl consumers. In the birds, the problem is very different, because the introduced pieces of lead (lead shot, lead of fishing) quickly are eroded and solubilized in the gizzard, causing a avian Saturnisme, often acute, very common in the water birds in the very driven out zones but also more frequent than one initially believed it at other species, out of the wetlands.

De many organic compounds of lead pass easily through the skin and from the intestinal barriers. It is the case of the lead tétraéthyl which was added to the gasoline, and is still in certain countries.
Certains popular remedies of which the “Azarcon” or the “greta” which contains up to lead 95%, used for " guérir" , are serious sources of intoxication. (Like the mercury formerly used in the Mercurochrome, which does not contain any today any more, this drug is so toxic that, if it kills all the Microbe S, it also contributes to poison the organization seriously, that of the children in particular.)

The military Medicine and the emergency Médecine have sometimes to face particular cases of lead poisonings related to wounds Balistique S (by Balle S or Grenaille of lead).

Up to one very recent period almost all the balls and shot were made up of lead. Lead is a particularly soft metal, especially if it were not hardened by addition from 5 to 10% of Arsenic or Antimoine (two metals which is also poisons) as it is often the case for the Munition S of firearms. When a ball or shot penetrates at high speed in an organization, in particular if there is contact with a bone, lead molecules and fragments can be torn off with the metal and dispersed in the organization via blood and the lymph. Exceptionally, it happens that the lead of a ball preserved in an organization can be at the origin of a mortal lead poisoning. The problem is more serious for balls or shot trapped in articulations where they are likely to break up more quickly into releasing their lead.

That applies to the animal killed with the Chasse (the good practices of butchery want that the flesh located around the zone penetrated by a ball is excisée).

Le case of the lead shot is more complex. The shot introduced by a bird is difficult to detect, and in a gizzard it is quickly eroded. In the flesh of a bird killed with hunting, it is even more difficult to detect, especially without Détecteur of metals. It is still often still present in the cooked meat and certain pies (gizzard), even introduced with the meat; degraded in a meat chopped or pie transform, or put in contact with an acid (Lemon-yellow, tomato sauce, Vinegar…), the lead shot can release from the significant quantities of lead and contaminate the meat and its sauce (if it is Acide). Chronic and unsuspected intoxications could thus concern the consumers of certain species at the risk (waterfowls reached of lead poisoning avian and/or contaminated by lead shot), even if they are a priori seldom mortals.

Individual susceptibilities and particular vulnerabilities

Vulnerability of the child:

Lead poisoning is more frequent and serious in the young child, for at least 4 reasons;

the young child is more likely to introduce contaminated substances. (The child naturally carries the fingers and the objects to the mouth (Pica). Moreover lead the oxide a Goût slightly has sweetened)
and because from 40 to 50% of the lead introduced by a child passes in his Sang (against 5 to 10% for an adult). Comparable lead is only eliminated very little and slowly naturally.
its Skin and its Muqueuse S is finer, and by kg of body weight the volume of food which it introduces, and the quantity of air which it inhales are more important.
It has because of its growth of the increased requirements out of calcium (for which lead substitutes itself chemically easily). Lead passes easily from the mother to the child via milk if she nurses.

A child is generally regarded as requiring care starting from a Plombémie of 100 µg by Liter of Sang, but this threshold could be re-examined with the fall because of effects shown on the brain with quite lower amounts.

Other particular vulnerabilities

the embryo and the fetus are much more sensitive to lead than the adult and the child . However, the blood lead of the pregnant woman passes very easily in the blood of the Fœtus, in substituent with calcium that the embryo pumps in the blood which arrives to him by the Umbilical cord.

a “lead poisoning female of the Ménopause” can exist. To this period, the woman indeed tends to lose calcium (Ostéoporose) and with this calcium, from the lead stored by the bones is abruptly released. If the woman had stored much of it, an intoxication généale can be induced, seldom suspectée by the doctor if he were not alerted on an exposure former to the lead (which can have taken place up to 20 years earlier) by the patient. Moreover, contamination by lead, in particular if there were joint contamination by copper seems to be able to worsen the osteoporosis by blocking the production of critaux of calcium hydroxyapatite and weakening the bone.

Lead poisoning induced by a fracture: All Fracture involves in physiological answer a release (fast, normal and important) of osseous calcium in blood; this calcium is used for osseous repair. This explains, that at an individual not presenting abnormal plombemy, but having stored lead in the bones before, a fracture can also release a very significant quantity of lead in blood, likely to induce a lead poisoning if necessary. This type of lead poisoning has very little chance to be detected if the doctor were not alerted on this risk by the patient (who often of it is not conscious). The symptoms are put on the account of the effect of shock or the traumatism related to the accident.

fetal Lead poisoning induced by a fracture which has occurred at the time of a pregnancy or right before: In this case lead " osseux" brutally released is collected by the fetus or the embryo at the same time as the calcium which it uses to build its skeleton and its organization. This risk is seldom taken into account by the medical teams during a fracture of expectant mother. In this case a deficiency of the iron and calcium bioassimilable mother strongly worsens the problem. Moreover, the fetus “detoxicating” thus the organization of his/her mother, no symptom appears at this one. And if the plombemy were sufficient to induce symptoms in the mother, the risk would be great that they are confused with turbid banals related to the pregnancy.

fetal Lead poisoning induced by breast feeding . A blood lead surge during breast feeding or at the end of the pregnancy (surge caused by the supply or a calcium deficiency related to the breast feeding, or induced by a fracture recent or undergone during breast feeding (cf § Ci above) can also induce a lead poisoning in the baby or the nursed young child.

Synergies: many Synergy S between lead and other pollutants seems possible. For example, Gorell and Al showed that lead associated with other cations of which of copper was implied in the Parkinson's disease.
Associé with alcohol, lead can have effects worsened on the fetus…

Sources of intoxication

A shown cause of lead poisoning of the adult and especially of the child is the intoxication by contaminated Viande animals which introduced lead resulting from the ammunition, cartridge S (and more rarely Balle S) used for the Chasse. In the large birds (such Goose S and Swan S) the lead of fishing is also a significant cause of avian Saturnisme, which can cause intoxication of consumers of Gibier. Some Champignon S are strongly bioaccumulator S of lead.

The gasoline was an important source of lead, in strong reduction where lead in the gasoline is prohibited, which is not the case in all the countries; in China, with the Nigeria as in other producer countries of Oil and in some Developing country, the gasoline is still leaded.

According to a conference of consensus of 2003 on lead and the expectant mother (Kremp, 2003), the red Wine would be the independent source of lead in the food of the French. It could be because of the lead desorbed by the wood of oaks of the barrels, because the juice of Raisin practically does not contain any. The Bière contains sometimes high rates of lead, probably because of the fixing of lead on the cuticule of the grains of Orge which are not washed before use. The Brass or the welding S of the installations could sometimes be in question. The Cocoa and the Chocolat contain of them sometimes alarming amounts, for reasons badly included/understood. In the animal, it is the Foie, but especially the bones which contain some more.

Effects and symptoms at the man

When the intoxication is light, the symptoms seldom make it possible to lead to the diagnosis of lead poisoning. With the increase in the lead rate in the organizations, the Symptôme S following appear:

Nausea S, Vomiting S, Diarrhea S Constipation, Headaches, with frequent loss of appetite and weight;
Appearance of a metal taste in the oral cavity, possibly followed in the cases of intoxication strong of appearance of an edging grisâtre or bluish on the Gums, said " “edging of Burton” " (very rare in the young child, more frequent in the seriously poisoned adult).
abdominal Pains (known as “colics of lead” );
Turbid neurological, with reduction in the cognitive capacity (difficulty of concentration, disturbs Mémoire), tiredness and lethargic behavior or on the contrary Hyperactivité;
Irritability; it is a symptom which was initially noted in school in the children of the areas or exposed families. But certain authors think that it was underestimated in the adult.
Insomnia;
Delay of mental development in the child, with irreversible after-effects if the intoxication related to the Embryon, the Fœtus or the young child;
Turbid psychomotor: Lead affects the nervous systems central and peripheral, initially in a completely painless way. One of the first signs of peripheral attack (chronic Neuropathy) being a weakness of the extensors of the hand (which appears after a few weeks of exposure). If the exposure perdure or is raised, of the joint pains appear, then a possible Paralysie of the member S;
Anemia
Dysfunction of the Kidney S;
arterial Hypertension;
male Sterility;
auditive Loss;
Hyperuricémie (urinary elimination excessive of Uric acid);
Cancer S (induced by the certain chemical shapes of lead);
Dead Coma then , generally caused by a Encéphalite.

Lead and epidemiology of violence and criminality:

The noxious effects of lead do not interest only the doctors. They worry also the policy, the persons in charge of health, the Assureur S and the economist S.
Le molecular lead is indeed neither Biodégradable, nor dégradable. And being bioaccumulable, it will remain for this reason a long time a problem of Public health in the majority of the countries, in spite of its prohibition of use in the Essence and paintings. Moreover the worldwide production of lead continued to grow at the beginning of the XXème century, with important exposures of the population in China and in the countries where the gasoline remained leaded.

One wonders for a long time if the social effects of the exposure to lead are limited to a simple irritability (for example noted in the children exposed to lead, and that one allotted to a possible suffering of the brain), or so beyond simplements effects penalizing for social integration of individuals, lead poisoning could lead to serious disorders of the behavior, sources of Violence and supporting criminal behaviors.

Lead poisoning and criminality: Rick Nevin (consulting in economy) has in May 2000 made public a test of evaluation quantitative of the problem. It concluded why according to the comparative study of the Statistique of average exposure to lead, and Criminalité, that the exposure to lead could explain to the the United States and in other countries 65% to 90% of the variation of the rates of the Criminalité forces, with waves of increase in criminality which follow the increase in the average plombemy systematically, with a light shift. It was the first time that an author so directly bound the increase in aggressive or criminal behaviors to an environmental exposure to lead.
Les results of this study was pointed out 7 years after (in July 2007) by Washington Post in an article which started again the interest carried to the lead intoxication like factor of violence.
Les results of Rick Nevin indeed was consolidated by the conclusions of Roger D. Masters of the University of Dartmouth and similar work of other researchers nonresulting from the world of medicine or toxicology. A document of Jessica Reyes economist of Amherst is available in pre-publication on line

Lead poisoning and schizophrenia: One wonders for a long time if lead can explain some turbid mental, of which some Schizophrénie.
- In January 2004 an article of newspaper Scientific American estimated in connection with schizophrenia that the blocking of the receivers NMDA (protein playing a crucial role in the development of the brain and the Cognition) could produce the symptoms of schizophrenia, but without explaining the mechanism of it.
- It since is recognized that lead is a powerful inhibiter of receiver NMDA, and in particular in the hippocampus.
- According to a recent article (2007) on the encephalopathy induced by the exposure of the brain to lead, lead also interferes with the phenomena of neurotransmission related to glutamate. Those are responsible for the activity of more than half of the synapses of the human brain, and are essential for the training. The receiver of glutamate, considered to explain the astonishing neuronal plasticity of the brain and the development, is a receiving molecule called N-methyl-D-ASPARTATe (NMDA). However this NMDA is selectively blocked by the lead, which to some extent passes the méningées barriers easily protecting the brain. The lead intoxication would thus disturb the neural networks of the training and would explain the disorders of the permanent conservation of the information lately acquired by the brain.

“uterine Lead poisoning” and schizophrenia : In an epidemiological study presented in the long run to annual convention 2004 meeting of the American Association for the Advancement off Science , to Seattle (the United States), Ezra Susser and its team have at the Columbia university of New York exploited the data of follow-up of a panel of 12.094 newborns with Oakland (California) of 1959 with 1966. Blood samples of Serum collected in their mothers whereas they were Enceinte S, had been frozen and preserve for a later analysis.
Les analyzes showed that the children exposed in utero tohigher lead rates presented a risk doubled to develop a schizophrenia or disorders connected later . The study must be prolonged on other populations and a panel of children even broader, with more precise questionnaires for the mothers in order to try to determine if periods ago of exposure in utero where the risk is higher to cause a future schizophrenia (one can suppose that the period known as of synaptogenèse is most critical, but that requires confirmation). Susser will
Ezra put forth the assumption of an impact on the brain of the fetus comparable with that of the alcohol which prevents the formation of neuronal connections precociously, which can lead to dead groups of cells which would have to play a part in the future development of the brain. This same study detected besides other factors as lead which can also act or perhaps to be added. The impact of alcohol was known, but the study showed that the child born of a mother who was seized up in the first part of her pregnancy have three times more risk to develop a schizophrenia later. Other studies also showed an increased risk to have a IQ low for the exposure in utero to these three factors (lead, alccol, influenza).

Tentative conclusion: the data seem to confirm the assumption put forth for a long time of a bond (nonexclusive) between exposure to behavioral lead (possibly in utero) and disorders, generating possible violences and conflicts. They clarify one day new violences which characterized certain periods and places or characterize still certain geographical areas where lead was massively used by industry, but also by the army and at the time of civil wars (in particular at the time of the world wars, and perhaps as of antiquity in the zones of contamination of the environment or the individuals). These results also encourage with éradiquer as fast as possible the lead of the ammunition, including hunting.

Medical care

It begins with the stop of the exposure, and if necessary the restoration of the old residences. The children should not have access to scaled paintings. The frequent washing of the toys, the hands, the nails limits the risk. To make run tap water of lead drains a few moments before consumption, avoid waterfowl or killed to the lead shot, vegetables and fruits of gardens polluted by lead, as well as the dishes, potteries and crockery terra cotta, tin, money welded or of decorative use, not certified suited to the food contact; to make sure of the absence of other sources of intoxication (ex lead shot swallowed with game and stored in the appendix); to avoid the cosmetics of the type Kohl or Surma and produced medicamentous of means-Eastern or Asian source.
cutaneous Décontamination, if necessary.
Assistance with natural elimination in the event of acute recent exposure: washing of stomach, rectal injection.
chelating Treatment, improving elimination by the Urine by transforming the tetraethyl Lead assimilable by the inorganic lead organization. This treatment is associated with a hyperhydratation (perfusion or absorption of a great quantity of liquids) in order to increase its effects (under medical control).
the treatment of the symptoms must continue with a long-term follow-up, in particular in the child, the woman and the young woman because of possible after-effects in the long run (in particular by relarguage of the lead stored in the bones at the time of the Grossesse or the Ménopause).
To regularly eat a not contaminated food, balanced and rich in Vitamin D, Iron and in Calcium limit the absorption of lead. The role of calcium remains discussed at the man, but there remains recommended by INVS.

Fight against lead poisoning

The recognition as an occupational disease allowed the best dealt with of the disease in the rich countries, where detection and the prevention remain the two medical pillars of this fight. The rich countries have all of the special programs of risk management of lead poisoning and of the disease in the child, in particular in the United States the fight against lead poisoning, infantile in particular, remains to be developed in many countries in particular in Asia where it strongly developed or in certain African countries as the Nigeria which knew the most lead rate in the gasoline.

Detection

It is necessary to plan the action and to improve the prevention. It is done, theoretically at least, in the majority of the countries, especially resting on the obligatory declarations sent by the doctors to the health authorities, but it is known that many cases are confused with other diseases. Some epidemiological studies, often in the big cities or around industrial sites made it possible to better know the disease.
En France, this disease is reproduced on the list of the Infectious illness in obligatory declaration, although it is not about a Infectious illness. Without being contagious, it can be indeed transmitted of the mother to the child.

In France

An action plan is based on the provisions of the law, with two great types of measurements:

Actions continuations with the descriptions (Art.L.1334-1 at 1334-4 of the C.S.P.); each case of infantile lead poisoning or a risk of accessibility to lead, makes it possible to the prefect to impose a diagnosis of the building (by its services or an approved operator). If a source of lead is present, it can impose palliative work necessary. If there is refusal of this last, the prefect makes carry out work with the expenses of the owner
Prévention (Art.L.1334-5 with L.1334-6 of the C.S.P.); a state of the risks of accessibility to lead must from now on be attached to any unilateral promise of sale or of purchase of an affected real estate in whole or part with the dwelling builds before 1948 or located in a zone at the risk of exposure to lead (zone delimited by order of the prefect, generally starting from data INSEE or of last censuses).

See too

History of lead poisoning, avian Lead poisoning
Heavy metals
toxic Ammunition

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