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ANTIMONY IN ENAMELLED WARE
1403 subcultural
according
group
to Dr.
of mental defectives, which, Penrose, comprise about a quarter
of the total inmates of the
Royal Eastern Institution.
ANTIMONY IN ENAMELLED WARE
THE Ministry of Health has published a report1 boy Dr. G. W. Monier-Williams on the risks of antimony poisoning when enamelled vessels are used for the preparation or storage of food. Outbreaks of antimony poisoning have arisen from the preparation of lemonade in such vessels, whether real lemons were used or so-called lemonade crystals in which tartaric acid replaces the natural citric acid of the fruit. There is no reason except cheapness why antimony should be found in enamelled ironware, since oxide of tin is a better material for giving the enamel the desired opacity. Tin is, however, the most expensive of the base metals and the use of antimony in its place may lessen the cost by 3 or 4 per cent. (say ld. in the shilling) which would hardly be a sufficient inducement to the purchaser if aware of the serious effects of antimony poisoning. It is clear, from the evidence adduced by Dr. Monier-Williams, that the trioxide, Sb20s is more dangerous than either the tetroxide Sb2O"" or the pentoxide SbOe. The trioxide or sodium metantimoniate, NaSb Os, is the only compound actually used, but as the enamel is subjected to a high temperature in the process of R-uxing it on the iron of the vessel, all three oxides may actually be found in the finished article and in fact were so found. The question of immediate interest is not how much antimony a glaze contains, but how much it is likely to yield to food or drink prepared or stored in vessels coated with it. Two classes of tests were therefore done on hollow-ware articles found to be made with antimonial glaze : (1) analysis of the glaze itself ; (2) estimation of the amount of antimony going into solution after allowing hot 2 per cent. tartaric acid to stand in the vessel for one hour with occasional stirring. It is noteworthy that the amount of antimony dissolved from the glaze, whether expressed as volume concentration in the acid solution or as weight per unit of surface exposed to its action, bore no constant ratio to the total amount found in the glaze detached from the vessel. This is no doubt partly due to the fact that a variable amount of the undercoat, which does not contain antimony, is usually chipped off with the actual glaze. Of 11 enamels examined 2 contained less than 1 per cent. of antimony in all states of oxidation, 3 between 1 and 2 per cent., 2 between 2 and 3 per cent., 1 between 3 and 4 per cent., 1 between 4 and 5 per cent., and 2 about 6 per cent. One small jug containing less than 1 per cent. yielded no antimony to tartaric acid ; a large jug containing 2’1per cent. yielded 138 mg. per litre, or 15-65 mg. per square decimetre (this was one of a batch which had caused poisoning at a London hospital); whilst a pie-dish containing over 3 per cent. gave 79’2 mg. per litre or 9’45 mg. per square decimetre, the antimony extracted being mostly in the form of the poisonous trioxide. The effect of repeated treatments with acid was not studied and it is conceivable that as the surface became rough the area of exposure would be increased and more antimony extracted. Having regard to the cases of poisoning (though happily none proved fatal) the prohibition of antimony in all classes of hollow-ware which might be used for food does not seem unreasonable. Some firms have used antimony 1Reports on Public Health and Medical Subjects, No. 73 H.M. Stat. Office. 4d.
compounds which they believed to be insoluble, and in some cases the antimony seems to have entered the glaze as an unsuspected impurity. But this circumstance affords little satisfaction to people who have been brought almost to death’s door. MORTALITY FROM PERNICIOUS ANÆMIA
FROM time to time various workers have brought forward figures suggesting that the incidence of pernicious anaemia differs between races. In particular it has been stated that the disease is unduly prevalent in the temperate zones of North America, Northern Europe, and the British Isles. In the minds of other observers there has been considerable doubt whether race really does play any important part in the distribution of its incidence and mortality. A recent study by Dr. Richard Friedlanderof 500 cases admitted to the Peter Bent Brigham Hospital (Boston, Massachusetts) between 1913 and 1932 appears to favour the existence of national differences. Of all the patients admitted to the hospital during the period of the survey (over 80,000) 0’62 per cent. had pernicious anaemia ; subdivision by nationality shows that over 1 per cent. of the patients from Canada, Sweden, and Denmark had the disease and over 0’7 per cent. of those from Ireland and England as compared with only 0-18 per cent. of those from Russia, 0’17 per cent. from Italy, and 0’06 per cent. amongst negro patients. The weakness of this type of evidence lies in the absence of all knowledge of the type of population from which the cases are drawn. Mortality from pernicious anaemia shows, as may be seen in the statistics of England and Wales, a steady and considerable rise with age and an appreciably higher incidence in the female sex. In other words a population consisting of persons in the older agegroups, or with a preponderance of females, will certainly show a higher incidence than a young population. If, for instance, the Russian patients in the hospital are drawn from a young immigrant male population, their incidence of pernicious anaemia is certain to be low. For a convincing solution of the problem case-rates at ages are essential; proportional rates such as those quoted above cannot be more than suggestive. That they may be fallacious is indicated by a comparison of the figures given by Friedlander for England and Scotland. Of the English patients admitted to the hospital 0-88 per cent. suffered from pernicious anaemia, while of the Scotch patients there were 0-43 per cent., or only half as many. Yet study of the death-rates given in the reports of the Registrars-General for England and Wales and Scotland shows that in fact the Scotch suffer consistently higher rates than the English at every age, and at all ages have a rate over 30 per cent. above that of England and Wales. Such a complete reversal of the real position in this case makes the validity of the other national differences very doubtful. Friedlander’s own opinion is that not only is predisposition to the disease racial in character but that it is largely confined to those individuals with a diathesis characterised by a fair complexion, light hair, blue eyes, and achlorhydria. It should be possible to collect satisfactory evidence on the importance of constitution. An analysis of 51 cases, 36 of which were autopsied prior to and 15 of liver since the advent therapy, showed no change since the introduction of this method of treatment in the weight of the liver, but the earlier group showed a greater weight of the spleen than those treated by liver. Of all cases treated with liver since 1
Amer. Jour. Med.
Sci., May, 1934, p. 634.
according
group
to Dr.
of mental defectives, which, Penrose, comprise about a quarter
of the total inmates of the
Royal Eastern Institution.
ANTIMONY IN ENAMELLED WARE
THE Ministry of Health has published a report1 boy Dr. G. W. Monier-Williams on the risks of antimony poisoning when enamelled vessels are used for the preparation or storage of food. Outbreaks of antimony poisoning have arisen from the preparation of lemonade in such vessels, whether real lemons were used or so-called lemonade crystals in which tartaric acid replaces the natural citric acid of the fruit. There is no reason except cheapness why antimony should be found in enamelled ironware, since oxide of tin is a better material for giving the enamel the desired opacity. Tin is, however, the most expensive of the base metals and the use of antimony in its place may lessen the cost by 3 or 4 per cent. (say ld. in the shilling) which would hardly be a sufficient inducement to the purchaser if aware of the serious effects of antimony poisoning. It is clear, from the evidence adduced by Dr. Monier-Williams, that the trioxide, Sb20s is more dangerous than either the tetroxide Sb2O"" or the pentoxide SbOe. The trioxide or sodium metantimoniate, NaSb Os, is the only compound actually used, but as the enamel is subjected to a high temperature in the process of R-uxing it on the iron of the vessel, all three oxides may actually be found in the finished article and in fact were so found. The question of immediate interest is not how much antimony a glaze contains, but how much it is likely to yield to food or drink prepared or stored in vessels coated with it. Two classes of tests were therefore done on hollow-ware articles found to be made with antimonial glaze : (1) analysis of the glaze itself ; (2) estimation of the amount of antimony going into solution after allowing hot 2 per cent. tartaric acid to stand in the vessel for one hour with occasional stirring. It is noteworthy that the amount of antimony dissolved from the glaze, whether expressed as volume concentration in the acid solution or as weight per unit of surface exposed to its action, bore no constant ratio to the total amount found in the glaze detached from the vessel. This is no doubt partly due to the fact that a variable amount of the undercoat, which does not contain antimony, is usually chipped off with the actual glaze. Of 11 enamels examined 2 contained less than 1 per cent. of antimony in all states of oxidation, 3 between 1 and 2 per cent., 2 between 2 and 3 per cent., 1 between 3 and 4 per cent., 1 between 4 and 5 per cent., and 2 about 6 per cent. One small jug containing less than 1 per cent. yielded no antimony to tartaric acid ; a large jug containing 2’1per cent. yielded 138 mg. per litre, or 15-65 mg. per square decimetre (this was one of a batch which had caused poisoning at a London hospital); whilst a pie-dish containing over 3 per cent. gave 79’2 mg. per litre or 9’45 mg. per square decimetre, the antimony extracted being mostly in the form of the poisonous trioxide. The effect of repeated treatments with acid was not studied and it is conceivable that as the surface became rough the area of exposure would be increased and more antimony extracted. Having regard to the cases of poisoning (though happily none proved fatal) the prohibition of antimony in all classes of hollow-ware which might be used for food does not seem unreasonable. Some firms have used antimony 1Reports on Public Health and Medical Subjects, No. 73 H.M. Stat. Office. 4d.
compounds which they believed to be insoluble, and in some cases the antimony seems to have entered the glaze as an unsuspected impurity. But this circumstance affords little satisfaction to people who have been brought almost to death’s door. MORTALITY FROM PERNICIOUS ANÆMIA
FROM time to time various workers have brought forward figures suggesting that the incidence of pernicious anaemia differs between races. In particular it has been stated that the disease is unduly prevalent in the temperate zones of North America, Northern Europe, and the British Isles. In the minds of other observers there has been considerable doubt whether race really does play any important part in the distribution of its incidence and mortality. A recent study by Dr. Richard Friedlanderof 500 cases admitted to the Peter Bent Brigham Hospital (Boston, Massachusetts) between 1913 and 1932 appears to favour the existence of national differences. Of all the patients admitted to the hospital during the period of the survey (over 80,000) 0’62 per cent. had pernicious anaemia ; subdivision by nationality shows that over 1 per cent. of the patients from Canada, Sweden, and Denmark had the disease and over 0’7 per cent. of those from Ireland and England as compared with only 0-18 per cent. of those from Russia, 0’17 per cent. from Italy, and 0’06 per cent. amongst negro patients. The weakness of this type of evidence lies in the absence of all knowledge of the type of population from which the cases are drawn. Mortality from pernicious anaemia shows, as may be seen in the statistics of England and Wales, a steady and considerable rise with age and an appreciably higher incidence in the female sex. In other words a population consisting of persons in the older agegroups, or with a preponderance of females, will certainly show a higher incidence than a young population. If, for instance, the Russian patients in the hospital are drawn from a young immigrant male population, their incidence of pernicious anaemia is certain to be low. For a convincing solution of the problem case-rates at ages are essential; proportional rates such as those quoted above cannot be more than suggestive. That they may be fallacious is indicated by a comparison of the figures given by Friedlander for England and Scotland. Of the English patients admitted to the hospital 0-88 per cent. suffered from pernicious anaemia, while of the Scotch patients there were 0-43 per cent., or only half as many. Yet study of the death-rates given in the reports of the Registrars-General for England and Wales and Scotland shows that in fact the Scotch suffer consistently higher rates than the English at every age, and at all ages have a rate over 30 per cent. above that of England and Wales. Such a complete reversal of the real position in this case makes the validity of the other national differences very doubtful. Friedlander’s own opinion is that not only is predisposition to the disease racial in character but that it is largely confined to those individuals with a diathesis characterised by a fair complexion, light hair, blue eyes, and achlorhydria. It should be possible to collect satisfactory evidence on the importance of constitution. An analysis of 51 cases, 36 of which were autopsied prior to and 15 of liver since the advent therapy, showed no change since the introduction of this method of treatment in the weight of the liver, but the earlier group showed a greater weight of the spleen than those treated by liver. Of all cases treated with liver since 1
Amer. Jour. Med.
Sci., May, 1934, p. 634.