On Phthisis Among Coal Miners
By T. G. Nasmyth, M.D., D.Sc., From the Annual Report for 1892 of the M.O.H. to the County of Fife.
Having been engaged in practice for many years in a district very much given to coal-mining, I was put in a position of being able to judge if phthisis or any other disease was specially liable to occur in coal miners, and to obtain all the information possible I prepared statistics for a period of fifteen years, showing the death-rates from phthisis in males and females. I also got all the information possible from the numerous benefit societies in the neighbourhood, showing what were the most common forms of illness from which miners suffered, and these, with the information I derived from my daily practice, gave me ample opportunity of judging what connection, if any, existed with the occupation of coal mining and diseases from which coal miners suffered. At the present time I shall deal only with the death-rates, but before doing so some reference is needed to collateral circumstances, which must be taken into account before coming to any decision in the matter.
The parish contains about 6,401 acres, of which about fifty-six are under water. The surface alternates with ridges, valleys, and plains, and the general declination is to the south and east. The contour lines run from 300 to 700 feet. The measures are principally limestone and coal. The soil is generally clay, and is cold and wet, and the whole parish is open and exposed to cold north and east winds. At the census 1871 there were 3534 people in the parish, 1,905 males and 1,629 females. At the 1891 census there were 8,298 people, of whom 4,423 were males and 3,875 females. The male population is much in excess of the female. In the whole county there were at last census 110 females to every 100 males, while in this parish there were 114 males to every 100 females. The industry of the parish is mainly coal mining, and this explains the preponderance of males over females. A considerable number of females are engaged at the "pit-heads," than whom it would not be easy to find stronger or more healthy subjects. A very large number are employed in the linen works in Dunfermline and Cowdenbeath, and the contrast between those so employed and those on the "pit-heads," as regards their health, is very marked indeed, the mill- workers being anaemic and delicate-looking in many cases. I mention these facts, as they explain, in my mind, why phthisis in the parish amongst females shows a tendency to increase, and is largely in excess compared with the rate amongst males.
For 1876-80, the male phthisis death-rate was very low - lower than for females. The crude death-rate was only 15.5 per 1,000 of population. The mean age at death for miners was 46.3, and the percentage of deaths from phthisis to total deaths was 5.5.
For 1881-85 the male phthisis death-rate was higher than for the five previous years, but much lower than for females. The rate for both sexes was very low. The mean age at death for miners was forty-five, and 9.6 percentage of the total deaths were from phthisis.
For 1886-90 the male phthisis death-rate was higher than for the two former periods, but much lower than amongst females for the same period. The crude death-rate was higher, and the mean age at death of miners was forty-seven years.
For these fifteen years it cannot be said that a high death-rate has prevailed amongst the males in a population largely employed in coal-mining, but quite the reverse ; and these statistics, as far as they apply to the population and deaths from phthisis upon which they are founded, go to disprove, what at one time was accepted as a fact, that coal-mining was productive of phthisis.
The air of coal mines has been the subject of research by one or two observers in this country. The first series of observations were those of Dr. Angus Smith, and dealt with the conditions existing 20 years ago. The last were made by the writer, and dealt with those conditions found in coal mines in Fifeshire, which may be taken as fairly representative of what is found generally in Scotland.
The most striking condition of the atmosphere in these mines was the uniform temperature. At a distance of about 1,000 yards from the pit bottom little or no variation in the temperature was noted from day to day over several months. The advantages of uniform temperatures are obvious, and when these are combined, as they are, with shelter from cold winds and rain, they place the occupation of coal mining on much more favourable conditions than are experienced by workmen exposed to quite the reverse conditions, such as ploughmen, railway surfacemen, and others. A great deal has been written about coal dust, and its effect in producing bronchial and pulmonary affections in coal miners. No doubt, when ventilation was imperfect in coal mines, a great deal of what is called "coal miner's lung" existed, but now-a-days, at least in Fifeshire, it is rarely seen. The Registrar- General for England goes so far as to state his belief that coal dust has a preservative rather than a destructive action on lung tissue. I have no hesitation in saying that coal dust in ordinary wounds of the skin and muscles has little or no injurious action, and that enormous wounds, which have been impounded with coal dust, heal as readily as others without this foreign matter.
If the same amount of dust, say from a road or street, had been introduced into such wounds, I need scarcely say the effect would have been quite different. I have never seen a wound produced in a coal mine to be followed by tetanus, and surgeons know that a very small wound polluted with ordinary garden soil is often followed by tetanus. Reasoning by analogy, my experience thus goes so far to support the theory that coal dust has not the pernicious action on the bronchial or pulmonary tissues as was at one time believed. If this is not actually the case, how can the fact be explained that a man who has worked in coal mines for many years, and after having discontinued to do so for about ten years, without having a symptom of any chest affection until he caught a "cold," and then began to expectorate " black spit." The coal dust had lain dormant during all those years without producing any irritation whatever. This case occurred in my own practice. The chemical condition of the air of coal mines is not one which can be discussed here, but my observations went to show that the condition found compared favourably with those found in schools, public buildings, and ordinary inhabited houses.