Lead poisoning and lead absorption

by Sir Thomas Morison Legge; Kenneth Weldon Goadby

The merits of soluble sulphides in “akremnin” soap have been advanced on the ground that the lead is converted into the insoluble black sulphide, which is thereby made visible to the eye, and the sight of which will, it is hoped, still further stimulate the desire to wash. Probably such lead as remains on the hands after well washing with soap is so closely adherent to the skin as to render risk of contamination of the food in this way negligible. Dr. Robertson, Chemist of the Royal Gunpowder Factory at Waltham Abbey, has found that results as good as those to be obtained from use of akremnin soap (and without any discoloration of the skin) are obtained from use of a solution made up as follows: Sal ammoniac added to saturation to a solution containing 8·5 c.c. of commercial hydrochloric acid (specific gravity, 1·15) per 100 c.c. of water. The procedure adopted at Waltham Abbey is—(1) Usual washing with soap, water, and a nail-brush; (2) scrubbing with the special solution by means of a nail-brush dipped in it; (3) rinsing in water; and (4) washing with soap and water.

Sommerfeld[2], from his wide experience, considers that pumice-soap, with the addition of turpentine, is the best cleansing material lead-workers can use.

Baths.

—Provision of bath accommodation is required under the special rules for white-lead factories and the regulations for electric accumulators. In several factories, however, baths are provided for the use of the workers. They naturally make for improvement in general health, but we cannot regard provision of them, any more than cloakrooms and mess-rooms, as likely to influence materially incidence of lead poisoning in a factory. The three requisites of (1) convenience and quickness, (2) comfort, and (3) regular use, can best be secured by the use of shower baths in place of slipper baths. The advantage they have are—(1) Initial cost of installation is less; (2) economy in space; (3) economy in water; (4) economy in time required for bathing; (5) no worker comes into contact with water used by another; (6) cleansing must be from the head downwards. Danger of scalding can be absolutely excluded by use of valve levers, so placed in relation to one another that steam cannot be turned on until the cold-water valve has been opened, and the heater can be so arranged that the water is not raised above a definite temperature.

Separation of Processes.

—Lead processes should, as far as possible, be carried on in such a way that there is aerial disconnection of one process from another. Separate workrooms, although desirable unless very small, may not always be possible, but by exhaust ventilation processes may be arranged so that dust is not a source of danger to persons working elsewhere. Instances could be given where, in paint and colour works, persons employed in the grinding of earth colours, in which no lead entered, succumbed to attacks of plumbism from contiguity of the plant with that for grinding lead colours. Threading up of castor runners on a wire previous to dipping used to be done, prior to 1901, in the dipping-house itself, with the result that some severe cases of poisoning occurred. By the rules of 1901 the process was required to be done in a place separate from any place where dipping (or other scheduled process) was carried on, and very few cases have occurred since. And if exhaust ventilation is relied on, Duckering’s experiments ([p. 206]) show the attention to detail necessary to prevent air charged with lead dust being drawn to the spot by the fan. The need for separation of processes becomes less in proportion as the cubic space of the room increases, and dust and fumes are locally removed.

Age of Employment.

—The same considerations as have been stated above govern this point also. Wherever lead dust or fumes arise, whether exhaust ventilation is applied or not, persons of either sex under eighteen years of age are probably rather more susceptible to attack by reason of natural failure to appreciate the risk run. When periodical medical examination in addition to exhaust ventilation has been adopted, the age limit can safely be reduced to sixteen. Where handling only of metallic lead and ordinary soldering with an iron are done, risk of contracting plumbism is so remote that an age limit may be unnecessary.

Wall Surface.

—Wherever walls are likely to be splashed, as in dipping rooms and enamelling workshops, the inner surface of the walls should be of glazed bricks or tiles or enamelled plates, any of which help also in increasing the light necessary in such rooms. If, on account of the cost, such perfectly smooth material is impracticable, the walls should be painted with oil colour, which will enable them periodically to be wet-cleansed. Dusting the walls is to be deprecated. Hence accumulations of dust and débris on ledges, rafters, beams, roofs, etc., should, in our opinion, only very occasionally be cleaned down. We consider that the risk from one big cleaning down is less than that from repeated small ones. (See [p. 218]).