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On this page : Pregnancy, ceramics and crystaware making
 
 
Pregnancy, Ceramics and Crystalware Making
by Edouard Bastarache
 
 
Possible hazards concerning pregnant or nursing women
 
There are four (4) large groups of hazards pregnant or nursing women must face in the world of ceramics and crystalware making :
-biological hazards,
-chemical hazards,
-ergonomic hazards,
-physical hazards.
 
For women who work, a certain number of countries such as Quebec have a specific legislation with regard to pregnant or nursing women.
There are various methods to eliminate at the source hazards to pregnancy :
- modification of the task which eliminates hazards,
- reassignment to a work station which does not involve hazards,
- pure and simple withdrawal from work when the two preceding options cannot apply.
 
I- Biological Hazards
 
A-Opportunistic infections
 
1-Introduction :
Micro-organisms are present everywhere in our environment: in the air, water, on surfaces, and on individuals of all kinds. They are invisible and relatively unperceived.
Micro-organisms are very numerous: 1 gram of earth may contain up to 25 billions micro-organisms (4 times the population of our planet).
The vast majority of micro-organisms in nature are saprophytes, i.e. that in the majority of situations they do not cause infections unless there are particular host conditions we will describe further : they are the opportunistic infections.
Pregnancy not being a disease, these infections have few chances to occur more frequently among pregnant ceramists than among those who are not.
 
2-Definition :
Infections among patients whose defence mechanisms are weakened, and this makes individuals particularly susceptible to infections. These infections are due to micro-organisms which usually are not very pathogenic.
Defence mechanisms, physiological, immunological can be disturbed, or a breach made in them, by a disease, a traumatism, or by procedures or products used for diagnostic or therapeutic goals.
 
Following are a few exemples.
 
3-Antibiotics and host defence mechanisms reduction :
A treatment by antibiotics modifies the normal flora of the skin, mucous membranes, digestive tract, and can lead to colonization of these organs by new micro-organisms.
This colonization is inoffensive if it is not followed by superinfection (invasion by indigenous germs, or micro-organisms from the environment).
 
Predisposing factors are :
Extremes of life
Chronic infections
Debilitating diseases
Use of excessive amounts of antibiotics
Use of broad spectrum antibiotics
 
4- Modifications of anatomical barriers :
Ex : a)Patients suffering from extensive burns
b)Patients having undergone therapeutic or diagnostic procedures.
 
The normal anatomical barriers of these patients are broken and they can not fight infections any more.
 
5-Disturbances of cellular or humoral defence mechanisms :
Neoplastic and immunodeficiency diseases
 
Ex : - Leukemias
- Myelomas
- Aplastic anemia
-AIDS
-Gammapathies
- Systemic lupus erythematosus
-Etc.
 
Treatments by radiotherapy.
Intensive immunosuppressive therapy.
Etc.
 
6- Cytotoxic drugs :
Opportunist infections are then due to a severe leucopenia (lowering of white blood cells).
 
7-Corticosteroids :
 
Their systemic use disturbs many aspects of the host defence mecanisms.
In addition, those who suffer from Cushing’s syndrome (increased secretion of an endogenous corticosteroid, cortisol) have an increased susceptibility to infections
 
B-Biological hazards of the pregnant worker in educational and pre-school settings.
 
This part applies to women who work in the school world, in nurseries and in other similar places where the presence of children is the main characteristic.
 
1-Introduction :
For the majority of biological hazards, we consider close contact as the sharing of the same room as the customers at risk, usually six (6) children and more, for a period of one hour or more. Generally, we do not consider significant the « one on one » type of contact with the customers at risk.
 
2-Without awaiting the occurence of cases :
 
a-Cytomegalovirus :
Immediate preventive withdrawal until the end of pregnancy for immune and non-immune workers in close contact with groups of children (6), younger than 5 years, in the following places :
Nurseries.
Serology is not necessary.
 
b-Parvovirus B 19 (5th disease) :
Preventive withdrawal from the beginning until the 20th week of pregnancy for non-immune workers (IgG) in close contact with groups of children (6) in the following places :
Elementary and secondary schools.
Preventive withdrawal while awaiting the result of serology.
 
c-Rubella :
Preventive withdrawal until the end of pregnancy for non-immune workers in close contact with groups of children (6) in the following places :
Elementary and secondary schools.
Preventive withdrawal while awaiting the result of serology in the absence of vaccination.
 
d-Chicken pox :
Preventive withdrawal until the end of pregnancy for unprotected workers in close contact with groups of children (6), 12 years old and less, in the following places :
Elementary schools and nurseries.
Is considered protected : a woman who has a documented history of chicken pox (serology is then not necessary) and a woman whose serology is positive.
Preventive withdrawal while awaiting the result of serology.
 
d-Mumps :
At the time of the declaration of one case in the class or the group (or in the environment at risk, during the course of an epidemic), preventive withdrawal up to 28 days after the last case.
Is considered protected : a woman born after 1969 and having received one dose of the vaccine, a woman having a doctor's certificate certifying that she suffered from the disease and a woman having had a positive serology.
Are considered at risk the following places :
Nurseries, schools, vacation camps.
 
3-When there are cases in the work environment :
 
Here are recommendations for biological hazards in the work environment when there is an outbreak of cases.
 
a-Parvovirus B 19 :
When the presence of cases is confirmed in secondary schools, preventive withdrawal until the 20th week of pregnancy for the non-immune workers (IgG) in close contact with groups of children (6).
Preventive withdrawal while awaiting the result of serology.
 
b-Whooping cough :
At the time of the declaration of a case in the classroom or in the group of the worker (index case) or two cases in the work environment. Are considered at the risk the following places :
Nurseries, elementary and secondary schools, holiday camps and youth reception centers.
Preventive withdrawal from the 30th week of pregnancy until the end.
 
c-Measles :
At the time of the declaration of one case in the work environment, preventive withdrawal up to 21 days after the last declared case for the unprotected workers considered among the contacts.
Is considered protected : a woman born in 1980 or after and having received two doses of the vaccine, a woman born between 1970 and 1979 and having received one dose of the vaccine, a woman born before January 1, 1970, a woman having a doctor's certificate certifying that she suffered from measles and a woman having had a positive serology.
Are defined as contacts : Personnel of the whole nursery, elementary or secondary schools, school buses.
 
d-Mumps :
At the time of the declaration of one case in the class or the group (or in the environment at risk, during an epidemic), preventive withdrawal up to 28 days after the last case.
Is considered protected : a woman born after 1969 and having received one dose of the vaccine, a woman having a doctor's certificate certifying that she suffered from the disease and a woman having had a positive serology.
Are considered at the risk the following places :
Nurseries, schools, vacation camps.
 
II-Chemical Hazards
 
Introduction
 
To be harmful to the ceramist who is pregnant or nurses, the chemical must be toxic, reach the embryo/fœtus/infant in a sufficient amount and for a long enough period of time.
It is not always easy to evaluate the risk because in several cases the exposure to chemicals is difficult to evaluate. There is not one ceramist who works exactly in the same manner, who uses the same materials, or uses the same amounts of a material in particular over a given period of time.
It is obvious that the wearing of an approved dust mask is good practice when dust air exposure justifies it, as at the time of mixing, spraying of glazes, and cleaning of the workshop, among other things.
In addition, exposure to carbon monoxide can occur at the beginning of bisque firing, and during reduction firing in a kiln using fossil fuel. It is also necessary to have good ventilation of the workshop during firings.
 
Here are some definitions concerning the effects on pregnancy :
 
Development (Effects on)
Indicate that effects can occur during the antenatal (before birth) and/or postnatal (after birth until puberty) development. These effects include/comprise congenital malformations (teratogenic effect), effects on the embryo or foetus (delay of growth, reduction in body weight, death, etc.) as well as postnatal effects (behavioural problems etc).
 
Reproduction (Effects on)
Indicate that harmful biological effects can occur during reproduction. These effects include/comprise the deterioration of the functions or of the capacity of reproduction, that is to say in particular spermatogenesis (formation of spermatozoa), oogenesis (formation of ovules), hormonal activity which could affect fecundation, conception.
 
Breast Milk (Data on)
Effects on the milk provided by the mother to feed her child. The data presented relate to the excretion or the detection of chemicals in milk as well as the deterioration of the quality of the milk or the amount of milk produced.
 
I-Following is a list of chemicals for which no data was found in the consulted documentary sources :
 
-Alumina,
-Alumina Hydrate,
-Antimony Trioxide,
-Arsenic Trioxide,
-Bismuth Trioxide,
-Cadmium Carbonate,
-Cadmium-Selenium Pigments,
-Cadmium Encapsulated Pigments,
-Calcium Carbonate,
-Cesium Monoxide,
-Chromium (Green Oxide),
-Cobalt Oxide,
-Copper, Black Oxide,
-Copper, Red Oxide,
-Copper Carbonate,
-Cristobalite,
-Cryolite,
-Dolomite,
-Dysprosium Oxide,
-Feldpars and Feldspathoids,
-Germanium Dioxide,
-Gold Chloride,
-Hafnium Oxide,
-Ilmenite,
-Iron, Red Oxide,
-Iron, Black Oxide,
-Iron, Yellow Oxide,
-Lead, Basic Carbonate,
-Lead, Red Oxide,
-Lead, Yellow Oxide,
-Lead Frits,
-Magnesium Carbonate,
-Man-Made Vitreous Fibers,
-Molybdene Trioxide,
-Nickel, Black Oxide,
-Nickel, Green Oxide,
-Niobium Pentoxide,
-Paraffin, thermal decomposition products,
-Potassium Permaganate,
-Platinium Resinate,
-Potassium Carbonate,
-Rubidium Oxide,
-Rutile,
-Silica, Quartz,
-Silver Nitrate,
-Sodium Azide,
-Sodium Carbonate,
-Sodium Silicate,
-Strontium Carbonate,
-Talc,
-Tantalum Pentoxide,
-Rare Earths,
-Thallium Oxide,
-Thorium Dioxide,
-Tin Dioxide,
-Titanium Dioxide,
-Tungstene Dioxide,
-Uranium, Depleted ,
-Wollastonite,
-Wood Ash,
-Zinc Oxide,
-Zircomium Silicate.
 
II-Now, a list of chemicals for which information was available in the consulted documentary sources :
 
Ammonia
 
Effects on development :
No data concerning an effect on the development was found in the consulted documentary sources
Ammonia is produced by the body. It is also an essential constituent for the normal development of human beings. An exposure in the work environment is not very likely to lead to an increase in the blood ammonia level and thus, it does not represent a hazard to development.
Effects on reproduction :
No data concerning the effects on reproduction was found in the consulted documentary sources.
Ammonia is normally produced by the body. It is also an essential constituent for the normal development of human beings. An exposure in the work environment is not very likely to lead to an increase in the blood ammonia level and thus, it does not represent a hazard for reproduction.
Effects on breast milk :
It is detected in human mother's milk.
Ammonia is a natural component of this milk.
 
Antimony
 
Effects on development :
I-In rats :
One did not observe harmful effects in the off-spring of female rats to which were given low concentrations of antimony trichloride in drinking water.
II-In humans :
A Russian study suggests that the exposure to antimony increases the risk of abortion and prematurity; it was also reported in this study that antimony crossed the placental barrier and was present in the amniotic fluid, placental tissue and umbilical blood.
Effects on the reproduction :
It was suggested that antimony is the cause of menstrual disturbances.
Effects on breast feeding :
Antimony can be excreted in mother's milk.
 
Asbestos
 
Effects on development :
The available data do not make it possible to make an adequate evaluation of the effects on development.
Effects on reproduction :
The available data do not make it possible to make an adequate evaluation of the effects on reproduction.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Barium Carbonate
 
Effects on development :
In animals :
No harmful anatomical effect was observed in the off-springs of rats and mice receiving up to 4000 ppm of barium chloride dihydrate in water, even if the weight at birth of the young ones was reduced.
Effects on reproduction :
In animals :
In rats and mice receiving up to 4000 ppm barium chloride dihydrate in water, the indices of reproduction were not altered.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Beryllium Oxide
 
Effects on the development :
It crosses the placental barrier in humans.
The available data do not make it possible to make an adequate evaluation of the effects on development.
Effects on the reproduction :
The data do not make it possible to make an adequate evaluation of the effects on reproduction.
Effects on breast milk :
I-In animals :
It is excreted in the mother's milk.
II-In humans :
There is no data concerning the excretion of beryllium oxide in breast milk.
However, beryllium was measured in milk (colostrum) in humans, but the source of the exposure is unknown.
The reported values varied from less than 0,05 to 1,6 µg/l.
 
Boron
 
Effects on development :
Concerning malformations, it seems that no case was reported in man in the pertaining literature.
Effects on reproduction :
I-In animals :
Animal experiments have shown disorders of reproduction related to the exposure to boric acid or borax. Effects on testicles and fertility were highlighted. The mechanism of this toxicity is not completely elucidated. In the female rat, an increase in the number of miscarriages and a fall of the number of litters were observed.
A study relating to development shows that boric acid causes malformations in three (3) species studied (rat, rabbit, mouse).
II-In humans :
An old study carried out in Russia on levels varying from 20 to 83 mg/m3 at 50% of the studied work stations i.e. 2 to 8 times the standard of exposure currently allowed, showed a reduction of sexual activity and a deterioration of the quality of the sperm.
In the USA, these results were not confirmed in a study in 542 workers whose average exposure was 19.7 mg/m3.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Cadmium Oxide
 
Effects on development :
It has an embryotoxic and/or foetotoxic effect in the animal. It crosses the placental barrier in the animal.
Effets on reproduction :
Toxic effects on reproduction were observed in the rat : a reduced number of spermatozoa per testicle and an increase in the length of the oestrous cycle.
No toxicity of reproduction was observed in the mouse.
Effects on breast feeding :
It is excreted in the mother's milk in the animal.
 
Carbon Monoxide
 
Effects on the development :
I-In animals :
It has an embryotoxic and/or foetotoxic effect in the animal. It can affect the postnatal development in the animal.
II-In humans :
It crosses the placental barrier in humans.
Effects on reproduction :
The available data do not make it possible to make an adequate evaluation of its effects on reproduction.
Data on breast milk :
There is no data concerning its excretion or detection in mother's milk
 
Carbon monoxide intoxication and pregnancy :
Carbon monoxide intoxication during pregnancy poses particular problems. It seems that a significant risk of foetal death and neurological anomalies exist following exposure of the mother to CO, with a risk of foetal death varying from 36 to 67 %. Ventilation being increased during pregnancy, it is possible that CO pulmonary absorbtion is greater in the pregnant woman. The affinity of foetal hemoglobin for CO is greater than that of maternal hemoglobin. An equilibrium state will be reached in the foetus and the elimination of CO is slower for the foetal circulation. The maximum level of carboxyhemoglobin reached during the intoxication could be greater in the foetus than in the mother.
On the basis of retrospective data, it seems that oxygen therapy is safe for the foetus and the mother. Precise information on hyperbaric is not established in a final manner but a carboxyhemoglobin of 15 % is often used by several experts as a critical value because of the greatest physiopathological sensitivity of the foetal circulation.
 
Cigarette smoke :
The exposure to tobacco smoke is also a source of exposure to carbon monoxide which can be the cause of a maternal and foetal carboxyhemoglobinemy. The exposure to tobacco smoke during pregnancy can cause an increase in the frequency of miscarriages, premature births, a reduction in the weight at birth, etc.
 
Recommendation :
The lady worker should not be exposed to CO levels exceeding 10 ppm weighted over 8 hours per workshift from now on.
 
Cobalt Carbonate
 
Effects on development :
No data concerning antenatal development was found in the consulted documentary sources.
It crosses the placental barrier in the animal.
Effects on reproduction :
No data concerning reproduction was found in the consulted documentary sources.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Dioxin (TCDD)
 
Effects on development :
I-In animals :
TCDD is teratogenic and toxic to the foetus. Studies in laboratory animals suggest that dioxins alter development (low birth weight, miscarriages, congenital malformations, etc.)
TCDD crosses the placental barrier.
II-In humans :
There are reports which indicate an increase in miscarriages or congenital malformations, more especially of the spine. We do not know much of the potential effects of dioxins and other chlorinated compounds on the development of the nervous system of children.
Effects on reproduction :
I-In animals :
The effects on reproduction seem to be very sensitive indicators of the toxicity of dioxin. Sudies in laboratory animals suggest unfavourable changes in reproduction (fertility, development of sexual organs, disturbances in the behaviour related to reproduction).
II-In humans :
We know few things of the potential effects of dioxins and other chlorinated compounds on human fertility. But occupational exposure to TCDD alters serum concentrations of male reproduction hormones.
Effects on breast milk :
TCDD is found in mother's milk; high levels of TCDD can be detected among adult children of mothers who were exposed to dioxins as production workers.
 
Lead
 
In lead glazes, it is necessary to use with precaution colouring materials such as oxides and carbonates of copper, cobalt and nickel, because they tend to increase the release of lead.
 
Sensitive populations :
People suffering from a neurological dysfonction;
People suffering from a renal disease;
People having certain genetic diseases, such as thalassemia, glucose-6 phosphate dehydrogenase deficiency, porphyrias, an excessive activity of the ALA synthase.
Children;
Pregnant or breast-feeding women;
The embryo or foetus;
Elderlies;
Smokers;
Alcoholics.
 
Inorganic Lead :
 
Effects on development :
In humans, harmful effects were reported on embryonic, fœtal and postnatal (mental) development. The nervous system under development appears more sensitive to lead than the already developed nervous system, making the exposure to lead dangerous during pregnancy and breast feeding. There is a possibility of an increased incidence of miscarriages in humans.
Research suggests an association between paternal exposure to lead and the risk of miscarriages. In humans, it crosses the placental barrier, and this transfer increases with the duration of the pregnancy.
Effects on reproduction :
Harmful effects of lead on human reproduction have been reported, but information on its possible impact among exposed populations is limited. Lead intoxication could cause a disturbance of LH secretation by the hypophyso-hypothalamic axis, and could also result in direct damage to the seminiferous testicular tubes.
Occupational exposure to lead seems to cause menstrual problems.
Effects on breast milk :
Breast-fed children can be exposed to lead via the mother's milk, but few data exist to evaluate and quantify this relation. This route of exposure is a potential hazard to children of nursing mothers currently exposed to lead just as for the children of mothers having a former exposure to lead, due to the release of the lead already stored in their bone stores.
 
Pre-employment Examination :
 
Women who are pregnant or who nurse should not be exposed to lead.
 
Preventive Withdrawal from Work :
 
Physicians must recommend that a lady worker be withdrawn from work when she is pregnant.
 
Lithium Carbonate
 
Effects on development :
I-In animals :
Animal studies suggest the possibility of an increase in congenital malformations but the relation between the exposure and the effect is not satisfactory because of experimental limitations.
II-In humans :
In a study in humans, only one (1) patient out of twenty-five (25) delivered a malformed baby.
It crosses the placental barrier.
Effects on reproduction :
In humans, no data concerning reproduction was found in the consulted documentary sources
Effects on breast milk :
It is excreted in human mother's milk.
 
Manganese, and Some Inorganic Compounds
(Carbonate, Dioxide, Oxide)
 
Effects on development :
Exposed pregnant women can present spontaneous miscarriages. In Russia, there was an excess of miscarriages among wives of workers employed in manganese processing plants.
Effects on reproduction :
Manganese could disturb libido according to some studies. It was indicated that a loss of libido and impotence, sometimes preceded by a phase of hypersexuality, were observed in subjects suffering from manganism.
Some studies showed a reduction of the number of children generated by some male workers during the period when they were exposed to manganese.
Effects on breast milk :
There is no data concerning excretion or detection in milk.
 
Nickel, General Information
 
Effects on development :
I - In animals :
Exposure of animals in gestation was associated with delayed embryonic development, an increase in resorptions, and an increase in structural malformations. It was noted, however, that the doses used were high and cannot reflect at all human exposures.
II-In humans :
Inceased incidences of congenital malformations were observed, and also increased threatened abortion and spontaneous miscarriages at the time of a study among 758 Russian women who were employed in a hydrometallurgic refinery of nickel.
An increase by six (6) of the relative risk of cardiovascular malformations was noted in the infants of women exposed to nickel.
Effects on reproduction :
I-In animals:
In laboratory animals, a range of effects on reproduction can be induced by nickel. In male rats, exposure to nickel salts resulted in degenerative changes of the testicles and epididymis, and effects on spermatogenesis.
II-In humans :
In the light of the results observed in rodents, investigations are necessary to study the unfavourable effects on reproduction among women exposed to nickel.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Tellurium Dioxide
 
Effects on development :
I-In animals :
According to the doses studied, TeO2 induced hydrocephaly, body oedema, exophthalmia, ocular haemorrhages, umbilical hernias, small kidneys, and smaller animals.
II-In humans :
No data concerning reproduction was found in the consulted documentary sources.
Effects on reproduction :
I-In animals :
TeO2 induces maternal toxicity.
II-In humans :
No data concerning reproduction was found in the consulted documentary sources.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Thallium, Métal
 
Effects on development :
I-In animals :
It crosses the placental barrier.
II-In humans :
Apart from low birth weight and and alopecia, fœtal development was not affected among 20 cases of intoxication during pregnancy.
Effects on reproduction :
There is only a limited number of data available on the effects of thallium on reproduction.
The menstrual cycle, libido and male potency can be negatively affected.
Chronic intoxication can affect sperm.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
Vanadium
 
Effects on development :
In animals, high doses of vanadium can affect to a significant degree the developpment of bones, and be associated with fractures of the spine, but not implantation.
Effects on reproduction :
I-In animals :
The studies of toxicity for reproduction in the rat and the mouse are negative with nontoxic doses to the mother.
II-In humans :
There is no indication that vanadium can unfavourably influence reproduction.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
 
III-Ergonomic Hazards
 
A-Work organization, number of hours per day :
Recommendation :
The pregnant worker should not work more than 8 hours per day, 40 hours per week from the moment the existence of her pregnancy is known.
 
B-Night work :
Recommendation :
The pregnant worker should avoid night work and be reassigned to a day or evening job from the moment the existence of her pregnancy is known.
 
C-Prolonged standing position :
Recommendation :
The pregnant worker should not have to work more than 6 hours in this position per workshift starting from the 24e week of pregnancy.
 
D-Pressure on the abdomen :
Recommendation :
The pregnant worker should avoid pressure on the abdomen starting from the 24e week of pregnancy.
 
E-Frequent flexions of the trunk (flexion, extension and rotation of the trunk) :
Recommendation :
The pregnant worker should avoid these frequent movements starting from the 24e week of pregnancy.
 
F-Lifting of heavy loads :
Recommendation :
The pregnant worker should not lift loads heavier than 15 kg, 10 times per day; or heavier than 10 kg, 15 times per day from the moment the existence of her pregnancy is known.
In no time, should she lift loads heavier than 20 kg.
 
IV-Physical Hazards :
 
Work in a hot environment.
Recommendation :
Considering that the standards of heat stress are established for average and acclimatized workers, we estimate that a pregnant worker should not be exposed to a WBGT (Wet Bulb Globe Thermometer) greater than 25C.
Considering that the employers do not have the appropriate equipment to measure WBGT, we will use a chart of the temperature of ambiant air and relative humidity to determine the thermal conditions not to exceed by a pregnant worker who has an average workload.
This table applies if the worker is not exposed to radiant heat and that she does not have to wear special clothing nor an overall . Air draughts are not taken into account.
 
The safe zone is located above the thick line.
 
 
 
 
 
References :
 
1-Occupational Medicine, Carl Zenz, last edition.
2-Clinical Environmental Health and Toxic Exposures, Sullivan & Krieger, last edition.
3-Sax’s Dangerous Properties of Industrial Materials, Lewis C., last edition.
4-Toxicologie Industrielle et Intoxications Professionnelles, Lauwerys R., last edition.
5-Chemical Hazards of the Workplace, Proctor & Hughes, 4e édition.
6-CSST-Québec, Service du Répertoire Toxicologique, 2005.
7-NIOSHTIC/OSHLINE, Canada, 2005.
8-National Library of Medicine, Toxline Special, USA, 2005
9-The Biological and Clinical Basis of Infectious Diseases, Shulman, Phair, Peterson & Warren, last edition.
10-Vademecum Clinique du Diagnostique et du Traitement, Fattorusso V. & Ritter O., last edition.
 
 
 
 

 
Edouard Bastarache M.D.
(Occupational & Environmental Medicine)
 
Author of " Substitutions for raw ceramic materials "
Tracy, Québec, CANADA
edouardb@colba.net
 
 
 
 
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