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TELEVISION IN SURGICAL OPERATIONS
802 with a metal stable under diaphragm varying atmospheric conditions and as giving the required performance. Small crystal insert receivers are given a word of special commendation, but the committee’s aid is designed for both this type and the earcap type. The receiver.with a flat earcap advocated in the report is a modification of a miniature unit developed originally for the Fighting Forces ; it weighs about an ounce. The battery replacement cost, according to the report, is about 1.1d. per hour of actual use with the external receiver type of aid ; while with the insert receiver aid the running cost is about 0.6d. per hour. most
suitable ; and was
a
crystal microphone as being
recommended
FUMIGATION WITH METHYL BROMIDE METHYL bromide is mainly used as a refrigerant, as a fire-extinguisher, and as a methylating agent. Recently it has become popular as a fumigant of ships, warehouses, and other premises to control insect pests, and in this connexion fatalities and poisonings have been reported. The chemical being highly toxic to human beings as
well as to insects, the Home Office useful pamphlet1 on the risks and
has
issued
a
or ethylene oxide. All rooms, compartments, and alleyways with walls common to those of the area to be fumigated should be evacuated, and warning notices should be affixed. Fumigation staffs should consist of at least two persons, and one of them at least should be in attendance throughout the fumigation and airing period. Both persons should have adequate colour-vision and should be trained in the use of protective and detector apparatus and in first-aid. The dose of methyl bromide should be injected from cylinders placed outside the fumigation area. Airing should be conducted and concluded before the entry of any person other than the operators, who should work in pairs and wear their respirators until tests show that the concentration of gas is a safe one. At this stage a preliminary certificate of clearance is to be issued and the fumigated area closed again for a period to guard against the risk of dangerous quantities of gas being subsequently evolved from A final certificate of clearance absorbent material. should not be given until thorough tests have been made. Ships should never be fumigated until all persons have been taken off, and special care should be taken to test the air in the holds before a clearance certificate is issued.
precautionary TELEVISION
measures.
bromide boils at a low temperature (45°C) and it is therefore usually distributed under slight pressure in cylinders containing the liquid, contact with which Clothing contaminated may cause severe blistering. with the liquid should instantly be removed because a high concentration of gas can arise from it. The gas is heavier than air and has greater powers of penetration through walls and sealing material than other common fumigants such as hydrogen cyanide or ethylene oxide. Deaths have resulted both from exposure to high concentrations of the gas and also from continued exposure to low concentrations. The gas is insidious because it has only a faint odour and also because the symptoms after exposure may be delayed for a day or more. The symptoms of poisoning are mainly referable to the nervous system and include headache, dizziness, diplopia, vomiting, and lethargy, with later convulsions and
Methyl
collapse. The precautions
In addition, all apparatus used for the delivery of methyl bromide gas into rooms should be tested before being used in practical operations. The halide detector lamp is recommended for detecting low concentrations of methyl bromide in the atmosphere. These lamps vary in sensitivity to the gas,
types probably not being sensitive enough to detect parts per million of methyl bromide, the figure given
some
the upper limit of safe concentration. Advice on suitable can be obtained from the director of the Pest Infestation Laboratory at Slough. It is desirable that the people carrying out fumigation operations should be given practical demonstrations of the performance of the lamps in known concentrations of methyl bromide. The lamps should be used to detect leaks at the time of fumigation, during the exposure period, and before a clearance certificate is issued. as
types
Each operator
or
other person
entering
the space under
fumigation must be provided with a protective apparatus
In high (oxygengenerating) or a positive-pressure air-breathing apparatus is necessary, but in low concentrations canister respirators of an appropriate type may be used. Before fumigation, rooms and other spaces should be sealed with an impervious material which should be of an even higher standard than for fumigations by HCN of proved efficiency against concentrations of the gas
1.
SURGICAL OPERATIONS
LAST February surgical operations were televised for the first time at the Johns Hopkins Hospital, Baltimore.! One camera was fixed 41/2ft. above the operatingtable, and the image was so sharp that the numbers on a dollar bill placed on the table could be clearly read on the projection screens. A second camera was installed in the gallery to give a general view of the theatre ; and the surgeon provided a running commentary through a microphone. The experiment is said to have proved that demonstration of operations to a conclusively group of more than three or four is best effected by television, even though, for the moment, reproduction is only in black-and-white. BRITAIN’S HEALTH
THE results of the medical examination of men and called to the colours in 1939-46 are summarised in a report from the Ministry of Labour and National Service.2 It will be remembered that grades i and 11 were deemed fit for military service, while grades ill and iv were not. Grade iia consisted of those who, though fit for service, were handicapped by defects of visual acuity or by deformity of the feet. Of the 3,240,906 youths under 21, 91 % fell into grades i and n, and 9% into grades 111 and iv ; and of the age-group 21-25 (1,085,908 men) 85% were fit and 15% unfit. At ages 26-35 (2,045,480 men) the percentages were 79 and 21, and at 36-45 (805,480 men) they were 65 and 35. One should be careful in using these figures as a basis for conclusions about the health of the country as a whole, for the scale is heavily weighted at the younger end, where one would expect to find the majority in good health. It is perhaps encouraging, however, that of the relatively few men over the age of 36 the proportion adjudged fit for service was as high as 65%. Women examined numbered 550,486-less than a tenth of the total of men. They were volunteers in the sense that they preferred joining the Forces to entering industry, and as might therefore be expected they had a rather better health bill than the men, though the difference in the proportions accepted and those refused was not great. Among the men eye trouble and foot trouble were about equally prevalent, but in the women deformities of the feet were noted nearly five times as often as defects in visual acuity. women
-
taken should be at least as rigid as those taken when HCN is used, and it is recommended that a pungent lacrimatory gas such as chloropicrin (5%) should be added to methyl bromide so that its presence in the air can easily be detected.
17
IN
bromide. self-contained
methyl a
Fumigation with Methyl Bromide. June, 1947. Pp. 8. 2d.
H.M.
Stationery Office.
1.
Trimble, I. R., Reese, F. M.
Bull. Johns
Hopk. Hosp. 1947, 81,
186.
2.
Report of the Ministry for 1939-46. Cmd. 7225. H.M. Stationery 7s. Office. Pp. 394.
suitable ; and was
a
crystal microphone as being
recommended
FUMIGATION WITH METHYL BROMIDE METHYL bromide is mainly used as a refrigerant, as a fire-extinguisher, and as a methylating agent. Recently it has become popular as a fumigant of ships, warehouses, and other premises to control insect pests, and in this connexion fatalities and poisonings have been reported. The chemical being highly toxic to human beings as
well as to insects, the Home Office useful pamphlet1 on the risks and
has
issued
a
or ethylene oxide. All rooms, compartments, and alleyways with walls common to those of the area to be fumigated should be evacuated, and warning notices should be affixed. Fumigation staffs should consist of at least two persons, and one of them at least should be in attendance throughout the fumigation and airing period. Both persons should have adequate colour-vision and should be trained in the use of protective and detector apparatus and in first-aid. The dose of methyl bromide should be injected from cylinders placed outside the fumigation area. Airing should be conducted and concluded before the entry of any person other than the operators, who should work in pairs and wear their respirators until tests show that the concentration of gas is a safe one. At this stage a preliminary certificate of clearance is to be issued and the fumigated area closed again for a period to guard against the risk of dangerous quantities of gas being subsequently evolved from A final certificate of clearance absorbent material. should not be given until thorough tests have been made. Ships should never be fumigated until all persons have been taken off, and special care should be taken to test the air in the holds before a clearance certificate is issued.
precautionary TELEVISION
measures.
bromide boils at a low temperature (45°C) and it is therefore usually distributed under slight pressure in cylinders containing the liquid, contact with which Clothing contaminated may cause severe blistering. with the liquid should instantly be removed because a high concentration of gas can arise from it. The gas is heavier than air and has greater powers of penetration through walls and sealing material than other common fumigants such as hydrogen cyanide or ethylene oxide. Deaths have resulted both from exposure to high concentrations of the gas and also from continued exposure to low concentrations. The gas is insidious because it has only a faint odour and also because the symptoms after exposure may be delayed for a day or more. The symptoms of poisoning are mainly referable to the nervous system and include headache, dizziness, diplopia, vomiting, and lethargy, with later convulsions and
Methyl
collapse. The precautions
In addition, all apparatus used for the delivery of methyl bromide gas into rooms should be tested before being used in practical operations. The halide detector lamp is recommended for detecting low concentrations of methyl bromide in the atmosphere. These lamps vary in sensitivity to the gas,
types probably not being sensitive enough to detect parts per million of methyl bromide, the figure given
some
the upper limit of safe concentration. Advice on suitable can be obtained from the director of the Pest Infestation Laboratory at Slough. It is desirable that the people carrying out fumigation operations should be given practical demonstrations of the performance of the lamps in known concentrations of methyl bromide. The lamps should be used to detect leaks at the time of fumigation, during the exposure period, and before a clearance certificate is issued. as
types
Each operator
or
other person
entering
the space under
fumigation must be provided with a protective apparatus
In high (oxygengenerating) or a positive-pressure air-breathing apparatus is necessary, but in low concentrations canister respirators of an appropriate type may be used. Before fumigation, rooms and other spaces should be sealed with an impervious material which should be of an even higher standard than for fumigations by HCN of proved efficiency against concentrations of the gas
1.
SURGICAL OPERATIONS
LAST February surgical operations were televised for the first time at the Johns Hopkins Hospital, Baltimore.! One camera was fixed 41/2ft. above the operatingtable, and the image was so sharp that the numbers on a dollar bill placed on the table could be clearly read on the projection screens. A second camera was installed in the gallery to give a general view of the theatre ; and the surgeon provided a running commentary through a microphone. The experiment is said to have proved that demonstration of operations to a conclusively group of more than three or four is best effected by television, even though, for the moment, reproduction is only in black-and-white. BRITAIN’S HEALTH
THE results of the medical examination of men and called to the colours in 1939-46 are summarised in a report from the Ministry of Labour and National Service.2 It will be remembered that grades i and 11 were deemed fit for military service, while grades ill and iv were not. Grade iia consisted of those who, though fit for service, were handicapped by defects of visual acuity or by deformity of the feet. Of the 3,240,906 youths under 21, 91 % fell into grades i and n, and 9% into grades 111 and iv ; and of the age-group 21-25 (1,085,908 men) 85% were fit and 15% unfit. At ages 26-35 (2,045,480 men) the percentages were 79 and 21, and at 36-45 (805,480 men) they were 65 and 35. One should be careful in using these figures as a basis for conclusions about the health of the country as a whole, for the scale is heavily weighted at the younger end, where one would expect to find the majority in good health. It is perhaps encouraging, however, that of the relatively few men over the age of 36 the proportion adjudged fit for service was as high as 65%. Women examined numbered 550,486-less than a tenth of the total of men. They were volunteers in the sense that they preferred joining the Forces to entering industry, and as might therefore be expected they had a rather better health bill than the men, though the difference in the proportions accepted and those refused was not great. Among the men eye trouble and foot trouble were about equally prevalent, but in the women deformities of the feet were noted nearly five times as often as defects in visual acuity. women
-
taken should be at least as rigid as those taken when HCN is used, and it is recommended that a pungent lacrimatory gas such as chloropicrin (5%) should be added to methyl bromide so that its presence in the air can easily be detected.
17
IN
bromide. self-contained
methyl a
Fumigation with Methyl Bromide. June, 1947. Pp. 8. 2d.
H.M.
Stationery Office.
1.
Trimble, I. R., Reese, F. M.
Bull. Johns
Hopk. Hosp. 1947, 81,
186.
2.
Report of the Ministry for 1939-46. Cmd. 7225. H.M. Stationery 7s. Office. Pp. 394.