TABLE IV.—ANALYSIS OF REPORTS ON LEAD POISONING BY CERTIFYING SURGEONS FROM JANUARY 1, 1900, TO DECEMBER 31, 1909.
| No. | Occupation. | Total. | Severity of Symptoms. | Number of Attack. | Main Symptoms. | |||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Severe. | Moderate. | Slight. | First. | Second. | Third, or Chronic. | Gastric. | Anæmia. | Headache. | Paretic. | Encephalo- pathic. | Rheumatic. | Other. | ||||||||||||||||||
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) | (13) | (14) | (15) | (16) | |||||||||||||||
| M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | M. | F. | |||
| 1 | Smelting of metals: | |||||||||||||||||||||||||||||
| Cases | 411 | — | 104 | — | 105 | — | 197 | — | 276 | — | 65 | — | 64 | — | 325 | — | 99 | — | 18 | — | 99 | — | 9 | — | 66 | — | 11 | — | ||
| Per cent. | 100 | — | 25·3 | — | 25·6 | — | 47·9 | — | 67·2 | — | 16·8 | — | 15·6 | — | 79·1 | — | 24·1 | — | 4·4 | — | 24·1 | — | 2·2 | — | 16·1 | — | 2·7 | — | ||
| 2 | Brass works: | |||||||||||||||||||||||||||||
| Cases | 70 | 4 | 26 | 2 | 20 | 1 | 22 | 1 | 40 | 3 | 11 | 1 | 17 | — | 57 | 4 | 28 | 3 | 16 | 3 | 28 | 2 | — | — | 9 | 1 | 3 | — | ||
| Per cent. | 100 | — | 37·1 | — | 28·6 | — | 31·5 | — | 57·1 | — | 15·7 | — | 24·3 | — | 81·4 | — | 40·0 | — | 22·9 | — | 40·0 | — | — | — | 12·9 | — | 4·3 | — | ||
| 3 | Sheet lead and lead piping: | |||||||||||||||||||||||||||||
| Cases | 102 | 4 | 25 | 1 | 29 | 1 | 47 | 2 | 72 | 3 | 17 | — | 11 | 1 | 82 | 2 | 28 | 1 | 9 | 1 | 26 | 2 | 2 | — | 11 | 1 | 1 | 1 | ||
| Per cent. | 100 | — | 24·5 | — | 28·4 | — | 46·1 | — | 70·6 | — | 16·7 | — | 10·8 | — | 80·4 | — | 27·5 | — | 8·8 | — | 25·5 | — | 2·0 | — | 10·8 | — | 1·0 | — | ||
| 4 | Plumbing and soldering: | |||||||||||||||||||||||||||||
| Cases | 186 | 30 | 65 | 6 | 49 | 6 | 65 | 16 | 114 | 22 | 30 | 1 | 32 | 3 | 146 | 25 | 58 | 14 | 23 | 10 | 46 | 7 | 10 | — | 21 | 4 | 8 | — | ||
| Per cent. | 100 | 100 | 34·9 | 20·0 | 26·3 | 20·0 | 34·9 | 53·3 | 61·3 | 73·3 | 16·1 | 3·3 | 17·2 | 10·0 | 78·5 | 83·3 | 31·2 | 46·7 | 12·4 | 33·3 | 24·7 | 23·3 | 5·4 | — | 11·3 | 13·3 | 4·3 | — | ||
| 5 | Printing: | |||||||||||||||||||||||||||||
| Cases | 190 | 6 | 55 | — | 43 | 1 | 82 | 5 | 118 | 6 | 29 | — | 33 | — | 144 | 6 | 41 | 3 | 22 | 1 | 36 | — | 8 | — | 18 | — | 8 | — | ||
| Per cent. | 100 | — | 28·9 | — | 22·6 | — | 43·2 | — | 62·1 | — | 15·3 | — | 17·4 | — | 75·8 | — | 21·6 | — | 11·6 | — | 18·9 | — | 4·2 | — | 9·5 | — | 4·2 | — | ||
| 6 | File-cutting: | |||||||||||||||||||||||||||||
| Cases | 174 | 34 | 85 | 8 | 34 | 5 | 48 | 21 | 49 | 24 | 39 | 4 | 78 | 6 | 104 | 23 | 50 | 17 | 15 | 2 | 80 | 3 | 7 | — | 16 | — | 20 | 3 | ||
| Per cent. | 100 | 100 | 48·9 | 23·5 | 19·5 | 14·7 | 27·6 | 61·8 | 28·2 | 70·6 | 22·4 | 11·8 | 44·8 | 17·6 | 59·8 | 67·7 | 28·7 | 50·0 | 8·6 | 5·9 | 46·0 | 8·8 | 4·0 | — | 9·2 | — | 11·5 | 8·8 | ||
| 7 | Tinning and enamelling of hollow-ware: | |||||||||||||||||||||||||||||
| Cases | 84 | 53 | 26 | 13 | 27 | 16 | 31 | 24 | 50 | 31 | 18 | 16 | 15 | 6 | 65 | 49 | 33 | 12 | 9 | 3 | 19 | 13 | 4 | 2 | 8 | 4 | 1 | — | ||
| Per cent. | 100 | 100 | 31·0 | 24·5 | 32·1 | 30·2 | 36·9 | 45·3 | 59·5 | 58·5 | 21·4 | 30·2 | 17·9 | 11·3 | 77·4 | 92·5 | 39·3 | 22·6 | 10·7 | 5·7 | 22·6 | 24·5 | 4·8 | 3·8 | 9·5 | 7·5 | 1·2 | — | ||
| 8 | White lead: | |||||||||||||||||||||||||||||
| Cases | 1,167 | 76 | 317 | 27 | 235 | 11 | 593 | 33 | 961 | 56 | 108 | 9 | 49 | 3 | 1,003 | 59 | 286 | 8 | 51 | 5 | 120 | 7 | 59 | 6 | 98 | 7 | 14 | 2 | ||
| Per cent. | 100 | 100 | 27·2 | 35·5 | 20·1 | 14·5 | 50·8 | 43·4 | 82·4 | 73·7 | 9·3 | 11·8 | 4·2 | 3·9 | 85·9 | 77·6 | 2·5 | 10·5 | 4·4 | 6·6 | 10·3 | 9·2 | 5·1 | 7·9 | 8·4 | 9·2 | 1·2 | 2·6 | ||
| 9 | Red lead: | |||||||||||||||||||||||||||||
| Cases | 108 | — | 30 | — | 31 | — | 45 | — | 90 | — | 8 | — | 8 | — | 87 | — | 28 | — | 8 | — | 14 | — | 9 | — | 13 | — | 3 | — | ||
| Per cent. | 100 | — | 27·8 | — | 28·7 | — | 41·7 | — | 83·3 | — | 7·4 | — | 7·4 | — | 80·6 | — | 25·9 | — | 7·4 | — | 13·0 | — | 8·3 | — | 12·0 | — | 2·8 | — | ||
| 10 | China and earthenware: | |||||||||||||||||||||||||||||
| Cases | 490 | 572 | 102 | 86 | 158 | 181 | 216 | 286 | 297 | 469 | 91 | 65 | 87 | 17 | 318 | 430 | 93 | 183 | 78 | 181 | 147 | 79 | 26 | 43 | 52 | 67 | 39 | 8 | ||
| Per cent. | 100 | 100 | 20·8 | 15·0 | 32·2 | 31·6 | 44·1 | 50·0 | 60·6 | 82·0 | 18·6 | 11·4 | 17·7 | 3·0 | 64·9 | 75·2 | 19·0 | 32·0 | 15·9 | 31·6 | 30·0 | 13·8 | 5·3 | 7·5 | 10·6 | 11·7 | 8·0 | 1·4 | ||
| 10 | a | Litho-transferers: | ||||||||||||||||||||||||||||
| Cases | 20 | 28 | 2 | 5 | 2 | 8 | 15 | 15 | 17 | 27 | 2 | — | — | 1 | 16 | 25 | 2 | 8 | 6 | 14 | 1 | 8 | — | 2 | 5 | 2 | — | 1 | ||
| Per cent. | 100 | 100 | 10·0 | 17·9 | 10·0 | 28·6 | 75·0 | 53·6 | 85·0 | 96·4 | 10·0 | — | — | 3·6 | 80·0 | 89·3 | 10·0 | 28·6 | 30·0 | 50·0 | 5·0 | 28·6 | — | 7·1 | 25·0 | 7·1 | — | 3·6 | ||
| 11 | Glass cutting and polishing: | |||||||||||||||||||||||||||||
| Cases | 47 | — | 20 | — | 11 | — | 16 | — | 21 | — | 9 | — | 17 | — | 28 | — | 9 | — | 2 | — | 14 | — | 2 | — | 4 | — | 9 | — | ||
| Per cent. | 100 | — | 42·5 | — | 23·4 | — | 34·0 | — | 44·7 | — | 19·1 | — | 36·2 | — | 59·6 | — | 19·1 | — | 4·2 | — | 29·8 | — | 4·2 | — | 8·5 | — | 19·1 | — | ||
| 12 | Enamelling of iron plates: | |||||||||||||||||||||||||||||
| Cases | 38 | 14 | 6 | 6 | 19 | 4 | 13 | 3 | 31 | 11 | 7 | 2 | — | — | 37 | 8 | 3 | 5 | 2 | 2 | 3 | 3 | — | 1 | 6 | 1 | — | — | ||
| Per cent. | 100 | 100 | 15·8 | 42·9 | 50·0 | 28·6 | 34·2 | 21·4 | 81·6 | 78·6 | 18·4 | 14·3 | — | — | 97·4 | 57·1 | 7·9 | 35·7 | 5·3 | 14·3 | 7·9 | 21·4 | — | 7·1 | 15·8 | 7·1 | — | — | ||
| 13 | Electric accumulators: | |||||||||||||||||||||||||||||
| Cases | 281 | — | 58 | — | 70 | — | 151 | — | 222 | — | 40 | — | 13 | — | 255 | — | 70 | — | 10 | — | 34 | — | 5 | — | 12 | — | 2 | — | ||
| Per cent. | 100 | — | 20·6 | — | 24·9 | — | 53·7 | — | 79·0 | — | 14·2 | — | 4·6 | — | 90·8 | — | 24·9 | — | 3·6 | — | 12·1 | — | 1·8 | — | 4·3 | — | 0·7 | — | ||
| 14 | Paint and colour works: | |||||||||||||||||||||||||||||
| Cases | 397 | 21 | 111 | 2 | 104 | 4 | 176 | 15 | 290 | 16 | 61 | 3 | 39 | 2 | 344 | 19 | 121 | 8 | 36 | 2 | 81 | 1 | 8 | 1 | 43 | 2 | 7 | — | ||
| Per cent. | 100 | 100 | 27·9 | 9·5 | 26·2 | 19·0 | 44·4 | 71·5 | 73·1 | 76·2 | 15·4 | 14·3 | 9·8 | 9·5 | 86·7 | 90·5 | 30·5 | 38·1 | 9·1 | 9·5 | 20·4 | 4·8 | 2·0 | 4·8 | 10·8 | 9·5 | 1·8 | — | ||
| 15 | Coach-making: | |||||||||||||||||||||||||||||
| Cases | 678 | 3 | 176 | — | 187 | 2 | 293 | 1 | 405 | 2 | 127 | — | 114 | 1 | 537 | 2 | 178 | — | 109 | — | 157 | 1 | 16 | — | 79 | — | 23 | — | ||
| Per cent. | 100 | — | 26·0 | — | 27·6 | — | 43·2 | — | 59·8 | — | 18·7 | — | 16·8 | — | 79·2 | — | 26·3 | — | 16·1 | — | 23·2 | — | 2·4 | — | 11·7 | — | 3·4 | — | ||
| 16 | Ship-building: | |||||||||||||||||||||||||||||
| Cases | 261 | — | 93 | — | 51 | — | 108 | — | 181 | — | 41 | — | 24 | — | 207 | — | 77 | — | 27 | — | 54 | — | 8 | — | 23 | — | 4 | — | ||
| Per cent. | 100 | — | 35·6 | — | 19·5 | — | 41·4 | — | 69·0 | — | 15·7 | — | 9·2 | — | 79·3 | — | 29·5 | — | 10·3 | — | 20·7 | — | 3·1 | — | 8·8 | — | 1·5 | — | ||
| 17 | Paints used in other industries: | |||||||||||||||||||||||||||||
| Cases | 405 | 42 | 127 | 11 | 97 | 7 | 174 | 22 | 238 | 36 | 83 | 4 | 71 | 1 | 329 | 36 | 108 | 21 | 40 | 13 | 110 | 12 | 10 | 1 | 41 | 3 | 8 | 1 | ||
| Per cent. | 100 | 100 | 31·4 | 26·2 | 23·9 | 16·7 | 43·0 | 52·4 | 58·8 | 85·7 | 20·5 | 9·5 | 17·5 | 2·4 | 81·2 | 85·7 | 26·7 | 50·0 | 9·9 | 31·0 | 27·2 | 28·6 | 2·5 | 2·4 | 10·1 | 7·1 | 2·0 | 2·4 | ||
| 18 | Other industries: | |||||||||||||||||||||||||||||
| Cases | 528 | 114 | 160 | 37 | 117 | 22 | 230 | 52 | 329 | 93 | 85 | 14 | 86 | 5 | 428 | 91 | 161 | 42 | 58 | 18 | 121 | 15 | 17 | 6 | 43 | 15 | 15 | — | ||
| Per cent. | 100 | 100 | 30·3 | 32·5 | 22·2 | 19·3 | 43·6 | 45·6 | 62·3 | 81·6 | 16·1 | 12·3 | 16·3 | 4·4 | 81·1 | 79·8 | 30·5 | 36·8 | 11·0 | 15·8 | 22·9 | 13·2 | 3·2 | 5·3 | 8·1 | 13·2 | 2·8 | — | ||
| Total cases | 5,637 | 1,001 | 1,588 | 204 | 1,389 | 269 | 2,522 | 496 | 3,800 | 799 | 871 | 119 | 758 | 46 | 4,512 | 779 | 1,473 | 325 | 539 | 255 | 1,190 | 153 | 200 | 62 | 568 | 107 | 176 | 16 | ||
| „ per cent. | 100 | 100 | 28·2 | 20·4 | 24·7 | 26·9 | 44·7 | 49·5 | 67·4 | 79·8 | 15·5 | 11·9 | 13·4 | 4·6 | 80·0 | 77·8 | 26·1 | 32·5 | 9·6 | 25·5 | 21·1 | 15·3 | 3·5 | 6·2 | 10·3 | 10·7 | 3·1 | 1·6 | ||
To reduce the size of the table, columns showing the number in each occupation in which (a) the severity of attack, and (b) the number of attack were not stated, have been omitted. Of the former there were 170, and of the latter 245. The total figures, however, in Column 3 include them.
[Table IV.] shows the severity of the attacks as stated by the surgeon, the number of attack, and the main symptoms. The personal element enters into the character of the reports, and symptoms which one surgeon might describe as slight another might regard as moderate, or even severe. In general, however, “slight” includes cases of (1) colic without complication, and of comparatively short duration; (2) anæmia in adolescence aggravated by employment; and (3) either of the above with tendency to weakness of the extensors. “Moderate” includes (1) a combination of colic with anæmia; (2) profound anæmia; (3) partial paralysis; and (4) cases in which there is constitutional debility. “Severe” includes (1) marked paralysis; (2) encephalopathic conditions—convulsions, optic neuritis, and mental affections; (3) grave undermining of the constitution associated with paralysis, renal disease, and arterio-sclerosis. The reports are made during the attack, and information is not received of the sequelæ which may supervene, except in the event of a later report as the result of fresh exposure to lead. Number of attack has reference to definite occurrence of disability. Transient attacks which have preceded the disabling condition have been usually disregarded. It was necessary to limit the number of attacks which might be regarded as indicating chronic plumbism, and all those included in Column 10 are either third attacks or cases of chronic lead poisoning. Among the main symptoms, the headings “Gastric,” “Paretic,” “Encephalopathic,” and “Rheumatic or Arthralgic,” represent fairly accurately the relative incidence of these in cases of lead poisoning in this country; those under the headings “Anæmia” and “Headache” are useful in comparing relative incidence on the two sexes, but they occur, probably, much more frequently than the figures would indicate; those under “Tremor” and “Other” are less valuable. Under “Other” are included “Gout,” “Nephritis,” or “Cerebral Hæmorrhage,” so that entry under this head indicates chronic, rather than mild, lead poisoning. The conclusions from the table are easy to draw, as, in general, the feature which causes severity of symptoms to be prominent leaves its mark also on “Number of Attack” and “Main Symptoms.” Thus, in the industries in which severe cases exceed the average (brass, plumbing, printing, file-cutting, tinning, glass-cutting, ship-building, paints used in other industries, and other industries), the chronic nature of the plumbism is markedly above the average, and some severe symptom, usually paralysis, is also above the average. An exception to this rule is china and earthenware, where severity is considerably below the average, but where, among men, the figures for chronic lead poisoning and paralysis are distinctly high. It will be seen, however, that the proportion of slight cases even in this industry is below the average. On the other hand, severity is below the average in smelting, white lead, red lead, litho-transfers, enamelling, electric accumulators, paints and colours, and coach-painting, and the symptoms in these industries are, in general, colic rather than high degree of paralysis; but in them a severe symptom which is above the average, in general, is encephalopathy. The explanation of these differences depends, we believe, on two factors: (1) Duration of employment, with which, naturally, the age of the worker is associated; (2) opportunity of inhaling lead dust. The longer the employment, the more likely, naturally, if absorption goes on, is the plumbism to become chronic, and to be associated with paralysis, its prominent sign. Duration of employment among males in file-cutting and china and earthenware, as contrasted, for instance, with that in white lead, is very much longer, and the same could be shown of comparatively new industries, such as electric accumulators and litho-transfers. Thus, in one year the age distribution and duration of employment of those attacked in three of these industries was as follows:
| Industry. | Age Distribution. | Duration of Employment. | ||
|---|---|---|---|---|
| Under 30. | Over 30. | Under 5 Years. | Over 5 Years. | |
| Per Cent. | Per Cent. | Per Cent. | Per Cent. | |
| China and earthenware | 59·4 | 40·6 | 52·2 | 47·8 |
| White lead | 45·7 | 54·3 | 86·8 | 13·2 |
| File-cutting | 22·9 | 77·1 | — | 100·0 |
Persons employed in the manufacture of white and red lead, electric accumulators, paints and colours, and the others named, are exposed essentially to dust from salts of lead, which are readily absorbed. Poisoning, therefore, if precautions are inadequate, will quickly show itself, causing certain workers to seek other employment after one attack. Poisoning thus produced is more likely to induce colic, or, if the dose has been large or the individual markedly susceptible, encephalopathic symptoms, than paralysis. On the other hand, the slowness of the onset of symptoms in the case of brass workers, plumbers, printers, file-cutters, and tinners, is more the result of inhalation of fumes or of dust of metallic lead than of salts of lead; or if the inhalation be of salts of lead, then of these in less amount and over a long period, with, as a result, gradual undermining of the constitution, showing itself in paralysis, arterio-sclerosis, and renal disease. The two factors indicated obviously account for the differences in severity and number of attack between males and females. If second and third attacks are comparatively fewer in females than in males, it follows that, in general, the attack will be less severe also, and this is brought out in the figures. Cerebral symptoms—encephalopathy, to which headache may be added—are more than twice as frequent in females as males. This may be due to idiosyncrasy, but it may very possibly be simply the result of short duration of employment of young workers in processes where dust of salts of lead is incidental.
Attacks generally are most frequent in the first or second year of employment. Thus, of 2,195 attacks reported in the four years 1904 to 1907, as to which sufficient data are given, 898 occurred in the first two years of employment, and of these 672 occurred in the first year—that is, three-sevenths of all the cases were reported during the first two years, and four-sevenths in the whole of the remaining years of employment. It is, unfortunately, impossible to say what is the proportion of attacks among those employed for any given age period. In some factories—as, for example, lead smelting works—the average duration of employment is about thirteen years. The length of employment preceding an attack was made out from reports on cases which occurred in the white lead industry in 1898—a time when a number of new workers were taken on to replace the female labour abolished in June of that year, and conditions as regards removal of dust were entirely different from what they are now. The figures, therefore, can only be considered to have bearing upon incidence under almost the worst possible circumstances. Of 155 attacks, duration of employment was stated to have been less than 1 week in 3, from 1 week to 1 month in 8, from 1 to 3 months in 62, from 3 to 6 months in 44, from 6 to 12 months in 12, and 1 year and over in 26.
Attempt has been made to discredit the value of Section 73 of the Factory Act, 1901, on the ground that the proportion of cases in which some degree of paralysis is present is very high as compared with the extent found by other observers. The points we have laid stress on—(1) duration of employment, (2) varying kinds and amounts of lead dust and fumes—are, we believe, quite sufficient to account for, and give value to, the figures dealt with. To them should be added another factor, though one of less account—namely, the extent to which particular muscles are used. In the case of file-cutters, for instance, there is no doubt that the cramped position of the left hand holding the chisel, and the work thrown on the right in holding the heavy mallet, determine the direction of the paralysis, especially on to the muscles of the thenar and hyperthenar eminences and of the fingers.
There is, however, difficulty in deciding whether such entries on reports as “weakness of arms and legs,” “weakness of arms,” “muscular weakness,” etc., should be interpreted as incipient paralysis.[A] With a disease like lead poisoning showing marked tendency to affect the muscles supplied by the musculo-spiral and other nerves, the only safe course was to include all these terms as equivalent to partial paralysis. [Table V.] on [p. 54] shows close parallelism for the six years.
[A] During the years 1910 and 1911 cases were classified so as to distinguish definite paralysis, as far as possible, from the more indefinite terms referred to, with the result tabulated opposite. We have little doubt that in most of the cases included in columns (3) and (6) some slight degree of paresis was present.