The poisoning of workers who are employed in manufacturing processes which naturally involve poisoning materials, is, to a very large degree, under control in the United States and other industrial countries. Such control is, however, a comparatively recent development.
Industrial poisoning is not so important a subject as industrial diseases in general, for not nearly so many people are employed in trades which carry a poison hazard as there are in the dusty trades or in hot and strenuous labor.
But the effects of poisons used in industry are more definite, more is known concerning their action, and, therefore, prevention is better understood.
All hard industrial labor takes a certain toll from the worker. The mortality of males who carry industrial insurance, according to Dublin, is higher than the average for all males from the age of 25 years on. It reaches it peak at the ages of 45 to 54. The most frequent causes of this excessive death rate are the degenerative diseasesapoplexy, Bright’s disease, hardening of the arteries and heart failure. It is supposed that long-continued strenuous labor, exposure to extreme heat, and to rapid changes of temperature, are contributory factors in the production of these troubles. But it may not be entirely that, for the type of bodily build which is the natural requirement of the man doing strenuous work is that associated with just the diseases mentioned.
In controlling industrial poisonings, the first thing that had to be learned was that certain symptoms and bodily changes were due to the chemical involved in the industry. This was not so easy as it sounds, as we shall see when we come to study the development of our knowledge of lead poisoning. It takes good detective work, and even yet there are frequent instances of industrial poisonings, that could not have been predicted when a new industry was started. The famous case of the painters of luminous dials on watches is an instance.
The next step in prevention, after the acquisition of knowledge, is plant management. This includes devices to prevent the formation of gases, fumes or dust, or the installation of exhausts to remove them. Protection of the worker by filter mask, gas mask, or positive pressure air mask, is another step.
The three highways by which poisons enter the system are the lungs, the skin and the gastro-intestinal tract. Of all, the latter is the least important in most instances, but still supervision of the worker’s intake of alcohol and his food is most important. Many a poison which would be eliminated under ordinary circumstances, intact, is rendered soluble by the ingestion of alcohol.
The influence of food on lead poisoning is notorious, and for many years English and German workers have been furnished milk free. No one knew any explanation of the value of this until quite recently.