- Email: [email protected]
Rainfall as a cause for spread of Diphtheria
408
THE
V~LUE
OF BACTERIOLOGY
" T h e Motcombe Stream thus constituted~ flows through Bay Pond, a series of dipping holes being made along its course for the use of the inhabitants. The water from the pump and from the dipping holes has been analysed and condemned (the Water being organically contaminated)."
IN P U B L I C RAINFALL
HEALTH
WORK,
AS A C A U S E F O R S P R E A D OF DIPHTHERIA. ~
VALUE OF BATERIOLOGY IN PUBLIC HEALTH WORK. * IT is right, before leaving this subject, to say that it is open to considerable doubt whether all the cases notified as Diphtheria during the year were cases of the genuine disease. Without the opportunity of a careful bacteriological investigation in each case it is impossible for anyone to speak positively on this matter. I have on more than one occasion pointed out the desirability of provision being made for carrying on effectively this increasingly important branch of sanitary work in every sanitary district. The recent developments of bacteriology in connection with the recognition, the treatment and the prevention of infectious disease, have been such as to have completely revolutiouised our knowledge in regard to these subjects. The influence of vaccination in protecting those who have undergone the operation from a subsequent attack of Small-pox, which was for so many years after Jenner's discovery of it a merely empirical fact, has now been brought into line with a number of other tacts of a similar kind in regard to other infectious diseases and a rational explanation of its action supplied. Both these conquests of preventive medicine have been in a large degree rendered possible by the improvements which science has of late years made in the mechanical appliances for and in the modes of conducting microscopic inquiry, and it is not too much to say that a bacteriological laboratory and a bacteriologist is as essential a part of the machinery which should be available in every district for the protection of the public health as is a chemical laboratory and an analyst. How such a requirement can be most conveniently met is a question which is open to consideration. But it would seem that the authorities to whom the Legislature has delegated the provision of the one can most suitably undertake what is simply an extension of cognate work. Probably the alterations in the machinery for vaccination which will be entailed by the general adoption of calf lymph will facilitate the solution of the problem. When the law makes it the duty of local authorities to provide calf lymph for the use of their districts, as it is pretty sure to do, it wiU have taken no inconsiderable step towards inducing them to provide bacteriolog/cal institutes for this purpose.
NEXT to the Small-pox epidemic the most important sanitary feature of the past year has been the rekindling of the epidemic of Diphtheria, which, like that of Measles, appeared to have been arrested during the previous year. This recru. descence of Diphtheria in the combined district has been most conspicuous in the Cireucester Urban and Rural and in the Gloucester Rural Districts, but it has also been equally marked in the Thornbury District, which does not belong to the combination. In the case of the Gloucester Rural District the cases occurred almost exclusively in the parishes adjoining the City, where there was, I have reason to believe, a considerable outbreak of the disease, and I have little doubt that the diffusion of the infection was largely due to school influences. In other parts of the district, especially in the town and neighbourhood of Cirencester, I could not satisfy myself that school influence played anything m o r e than a subordinate if any part in the diffusion of the infection. Indeed, the actual number of cases notified was not sufficiently large to make it probable that the schools were an important factor in the case. What particularly impressed me in connection with this subject was the fact that whilst for the first eight or nine months in the year, which were exceptionally fine and dry, Diphtheria was practically absent from the district, it suddenly •made its appearance about September, after the occurrence of a he~,vy rainfall. This was most markedly the case in the suburbs of Gloucester, where the disease exhibited in the relatively small number of children who were attacked by it a high degree of mortality. Assuming this to have been something more than a mere coincidence the connection between the two facts may have been due to one or more ofthreecauses, viz. : - - ( 0 to the influence of moisture or the heated soil, so much of which in the neighbourhood of towns is unavoidably polluted by sewage and other similar matters, or (z) to effect of the heavy rainfall in stirring up the contents of the sewers, or (3) to the influence of the same condition in driving out the ground air out of soil, and with it the germs of the disease. In the neighbourhood of the Bristol Road, where the largest number of cases occurred, the emanations from the main sewer had been very much complained of for some time before the rain fell ; but, from the fact that the disease appeared about the same time in other localities inthe county where there were no sewers, their influence would appear to be at the least doubtful In all localities, too, in which the disease showed itself, except in a portion of the suburbs of Gloucester, which is to all intents and purposes a part of the city, the cases
*M.O.H. Gloucester Combined.--A.R., I896.
• IVI.O.H.GloucesterCombined.--A R. z896.
THE
W A S T E A C I D F R O M M E T A L WORKS. were so sporadic in their character as to suggest rather a widely spread atmospheric influence, acting upon subjects who were specially amenable to its influence, than one of a concentrated and local character affecting generally those in its immediate neighbourhood. Indeed, the experience of the past year has only confirmed the impression which I have for some time entertained that the personal factor in Diphtheria, as one ordinarily meets with it, is much more important than the impersonal one, that is to say, that the germ itself is probably much more common than is generally suspected, and that its influence in actually exciting disease is largely dependent on its having the chance to localise itself in the nose, throat, or windpipe of a child, who, by personal predisposition, as by previous attacks of congestion of the tonsils, exhibits a special receptivity for it. WASTE ACID FROM METAL WORKS. * THE Sanitary Committee of the Worcestershire County Council have had under their consideration the pollution of the river Stour, due to the discharge of waste acid from the galvanising works in the district. The medical officer of health was instructed to report " a s to the extent to which acid turned into streams is injurious to health, and as to what practicable means are available for preventing the pollution of rivers and streams from this cause." Dr. Fosbroke's report in pursuance of that instruction, the basis of his communication, forms an excellent summary of the best known means of rendering waste acid harmless. That there is need for some steps to prevent pollution from this cause is evident from the fact that the 17 manufacturers in the county area use I,o53 carboys of acid, equivalent to some zT,ooo gallons of waste per week. It appears that the greater part of the waste is discharged, without treatment, into the Stour. As regards " t h e extent to which acid turned into streams is injurious to health, Dr. Fosbroke states that he has made inquiries of ' m a n y medical officers of health and public analysts' and finds that ' there is a general consensus of opinion among such officials, that there is no evidence to support the view that ' acid turned into streams is injurious to health.'" Damage to brick sewers through the passage of crude waste acid has been reported from Birmingham and Wolverhampton, and "iron pipe sewers are said to suffer more than stoneware." At Wolverhampton the large amount of iron discharged on the sewage farm, simple irrigation alone being used, "greatly interfered with the sewage treatm e n t " and was "quite poisonous to vegetation." A proposal to treat the pickle at the farm with lime • A Report to the Sanitary Committee of the Worcestershire County Councilj by G. H. Fosbroke, M.D.j County Medical Officer,July, I897.
409
was found impracticable owing to the intermittent amounts to be treated. Ultimately the Corporation of Wolverhampton took steps to prevent the discharge of untreated waste into the sewers. Mr. Jones, county analyst for Staffordshire, "is of opinion that, provided muriatic pickle be properly treated before being added to the sewage, the sewers cannot be injured, and the sewage itself is improved." The acids used in the pickle tubs are commercial sulphuric and hydrochloric. The ~' practicable means available for preventing the pollution of rivers and streams" have to be considered under two heads. In Worcestershire hydrochloric acid is more used owing to its cheapness and to its less vigorous influence on the iron to be cleansed. When sulphuric acid is used the resulting sulphate of iron can be readily recovered and has a commercial value. The exhausted pickle is taken into w~oden troughs (lead lined)provided with boards on which the sulphate crystallises out. The liquor left, unexhausted acid, is returned to the pickle tub. In fact, the acid works round in a circle from pickle tub to crystallising trough and back to tub. The value of the crystals varies from i2s. to 2os. (or even 35s.) per ton. Common brown acid averages about ~ 4 per ton in price. Twenty-two hundredweight of the acid will yield about five tons of crystals, which, at I5S. per ton, areworth.~Z'3 x5s. , a good set off against the cost of acid (.~4 8s.). There is, therefore, every reason for endeavouring to avoid wasting exhausted pickle from a sulphuric acid bath. With hydrochloric acid the case is different. Several methods are described, all are expensive, and only one ("Turner's process ") has any claim to financial success. In this process the acid liquor is taken slowly over the heated bed o f a reverberatory furnace with access of air, the acid being freed and recovered in scrubber towers, and the iron being reduced to ferric oxide, which can be used as a eolour or for "fettling" in furnaces. Messrs. Walker, of Walsall, have this process in use and have obtained a favourable balance. Their plant consists of two furnaces evaporating z 5 tons during the week, working continuously. One ton of coke evaporates IO-XZtons of waste acid and one man can attend to the two furnaces. These furnaces are worked under the most favourable (economically) conditions and with smaller amounts of waste, similarly favourable results cannot be expected. Otherproeesses consist in neutralising the liquor with lime, soda, or ammonia. Properly effected, the resultant liquid, after settling, is free from acid and iron. These processes leave a sludge to be dealt with, involving, in certain instances, heavy expenditure. According to Mr. A. Crosbie, of Wolverhampton, a rough estimate for the lime process would vary from 3s. 4d. to 5s. 6d. per ton of waste liquor. There would be something like 7~ ewes. of sludge from each ton treated. It is not 20
THE
V~LUE
OF BACTERIOLOGY
" T h e Motcombe Stream thus constituted~ flows through Bay Pond, a series of dipping holes being made along its course for the use of the inhabitants. The water from the pump and from the dipping holes has been analysed and condemned (the Water being organically contaminated)."
IN P U B L I C RAINFALL
HEALTH
WORK,
AS A C A U S E F O R S P R E A D OF DIPHTHERIA. ~
VALUE OF BATERIOLOGY IN PUBLIC HEALTH WORK. * IT is right, before leaving this subject, to say that it is open to considerable doubt whether all the cases notified as Diphtheria during the year were cases of the genuine disease. Without the opportunity of a careful bacteriological investigation in each case it is impossible for anyone to speak positively on this matter. I have on more than one occasion pointed out the desirability of provision being made for carrying on effectively this increasingly important branch of sanitary work in every sanitary district. The recent developments of bacteriology in connection with the recognition, the treatment and the prevention of infectious disease, have been such as to have completely revolutiouised our knowledge in regard to these subjects. The influence of vaccination in protecting those who have undergone the operation from a subsequent attack of Small-pox, which was for so many years after Jenner's discovery of it a merely empirical fact, has now been brought into line with a number of other tacts of a similar kind in regard to other infectious diseases and a rational explanation of its action supplied. Both these conquests of preventive medicine have been in a large degree rendered possible by the improvements which science has of late years made in the mechanical appliances for and in the modes of conducting microscopic inquiry, and it is not too much to say that a bacteriological laboratory and a bacteriologist is as essential a part of the machinery which should be available in every district for the protection of the public health as is a chemical laboratory and an analyst. How such a requirement can be most conveniently met is a question which is open to consideration. But it would seem that the authorities to whom the Legislature has delegated the provision of the one can most suitably undertake what is simply an extension of cognate work. Probably the alterations in the machinery for vaccination which will be entailed by the general adoption of calf lymph will facilitate the solution of the problem. When the law makes it the duty of local authorities to provide calf lymph for the use of their districts, as it is pretty sure to do, it wiU have taken no inconsiderable step towards inducing them to provide bacteriolog/cal institutes for this purpose.
NEXT to the Small-pox epidemic the most important sanitary feature of the past year has been the rekindling of the epidemic of Diphtheria, which, like that of Measles, appeared to have been arrested during the previous year. This recru. descence of Diphtheria in the combined district has been most conspicuous in the Cireucester Urban and Rural and in the Gloucester Rural Districts, but it has also been equally marked in the Thornbury District, which does not belong to the combination. In the case of the Gloucester Rural District the cases occurred almost exclusively in the parishes adjoining the City, where there was, I have reason to believe, a considerable outbreak of the disease, and I have little doubt that the diffusion of the infection was largely due to school influences. In other parts of the district, especially in the town and neighbourhood of Cirencester, I could not satisfy myself that school influence played anything m o r e than a subordinate if any part in the diffusion of the infection. Indeed, the actual number of cases notified was not sufficiently large to make it probable that the schools were an important factor in the case. What particularly impressed me in connection with this subject was the fact that whilst for the first eight or nine months in the year, which were exceptionally fine and dry, Diphtheria was practically absent from the district, it suddenly •made its appearance about September, after the occurrence of a he~,vy rainfall. This was most markedly the case in the suburbs of Gloucester, where the disease exhibited in the relatively small number of children who were attacked by it a high degree of mortality. Assuming this to have been something more than a mere coincidence the connection between the two facts may have been due to one or more ofthreecauses, viz. : - - ( 0 to the influence of moisture or the heated soil, so much of which in the neighbourhood of towns is unavoidably polluted by sewage and other similar matters, or (z) to effect of the heavy rainfall in stirring up the contents of the sewers, or (3) to the influence of the same condition in driving out the ground air out of soil, and with it the germs of the disease. In the neighbourhood of the Bristol Road, where the largest number of cases occurred, the emanations from the main sewer had been very much complained of for some time before the rain fell ; but, from the fact that the disease appeared about the same time in other localities inthe county where there were no sewers, their influence would appear to be at the least doubtful In all localities, too, in which the disease showed itself, except in a portion of the suburbs of Gloucester, which is to all intents and purposes a part of the city, the cases
*M.O.H. Gloucester Combined.--A.R., I896.
• IVI.O.H.GloucesterCombined.--A R. z896.
THE
W A S T E A C I D F R O M M E T A L WORKS. were so sporadic in their character as to suggest rather a widely spread atmospheric influence, acting upon subjects who were specially amenable to its influence, than one of a concentrated and local character affecting generally those in its immediate neighbourhood. Indeed, the experience of the past year has only confirmed the impression which I have for some time entertained that the personal factor in Diphtheria, as one ordinarily meets with it, is much more important than the impersonal one, that is to say, that the germ itself is probably much more common than is generally suspected, and that its influence in actually exciting disease is largely dependent on its having the chance to localise itself in the nose, throat, or windpipe of a child, who, by personal predisposition, as by previous attacks of congestion of the tonsils, exhibits a special receptivity for it. WASTE ACID FROM METAL WORKS. * THE Sanitary Committee of the Worcestershire County Council have had under their consideration the pollution of the river Stour, due to the discharge of waste acid from the galvanising works in the district. The medical officer of health was instructed to report " a s to the extent to which acid turned into streams is injurious to health, and as to what practicable means are available for preventing the pollution of rivers and streams from this cause." Dr. Fosbroke's report in pursuance of that instruction, the basis of his communication, forms an excellent summary of the best known means of rendering waste acid harmless. That there is need for some steps to prevent pollution from this cause is evident from the fact that the 17 manufacturers in the county area use I,o53 carboys of acid, equivalent to some zT,ooo gallons of waste per week. It appears that the greater part of the waste is discharged, without treatment, into the Stour. As regards " t h e extent to which acid turned into streams is injurious to health, Dr. Fosbroke states that he has made inquiries of ' m a n y medical officers of health and public analysts' and finds that ' there is a general consensus of opinion among such officials, that there is no evidence to support the view that ' acid turned into streams is injurious to health.'" Damage to brick sewers through the passage of crude waste acid has been reported from Birmingham and Wolverhampton, and "iron pipe sewers are said to suffer more than stoneware." At Wolverhampton the large amount of iron discharged on the sewage farm, simple irrigation alone being used, "greatly interfered with the sewage treatm e n t " and was "quite poisonous to vegetation." A proposal to treat the pickle at the farm with lime • A Report to the Sanitary Committee of the Worcestershire County Councilj by G. H. Fosbroke, M.D.j County Medical Officer,July, I897.
409
was found impracticable owing to the intermittent amounts to be treated. Ultimately the Corporation of Wolverhampton took steps to prevent the discharge of untreated waste into the sewers. Mr. Jones, county analyst for Staffordshire, "is of opinion that, provided muriatic pickle be properly treated before being added to the sewage, the sewers cannot be injured, and the sewage itself is improved." The acids used in the pickle tubs are commercial sulphuric and hydrochloric. The ~' practicable means available for preventing the pollution of rivers and streams" have to be considered under two heads. In Worcestershire hydrochloric acid is more used owing to its cheapness and to its less vigorous influence on the iron to be cleansed. When sulphuric acid is used the resulting sulphate of iron can be readily recovered and has a commercial value. The exhausted pickle is taken into w~oden troughs (lead lined)provided with boards on which the sulphate crystallises out. The liquor left, unexhausted acid, is returned to the pickle tub. In fact, the acid works round in a circle from pickle tub to crystallising trough and back to tub. The value of the crystals varies from i2s. to 2os. (or even 35s.) per ton. Common brown acid averages about ~ 4 per ton in price. Twenty-two hundredweight of the acid will yield about five tons of crystals, which, at I5S. per ton, areworth.~Z'3 x5s. , a good set off against the cost of acid (.~4 8s.). There is, therefore, every reason for endeavouring to avoid wasting exhausted pickle from a sulphuric acid bath. With hydrochloric acid the case is different. Several methods are described, all are expensive, and only one ("Turner's process ") has any claim to financial success. In this process the acid liquor is taken slowly over the heated bed o f a reverberatory furnace with access of air, the acid being freed and recovered in scrubber towers, and the iron being reduced to ferric oxide, which can be used as a eolour or for "fettling" in furnaces. Messrs. Walker, of Walsall, have this process in use and have obtained a favourable balance. Their plant consists of two furnaces evaporating z 5 tons during the week, working continuously. One ton of coke evaporates IO-XZtons of waste acid and one man can attend to the two furnaces. These furnaces are worked under the most favourable (economically) conditions and with smaller amounts of waste, similarly favourable results cannot be expected. Otherproeesses consist in neutralising the liquor with lime, soda, or ammonia. Properly effected, the resultant liquid, after settling, is free from acid and iron. These processes leave a sludge to be dealt with, involving, in certain instances, heavy expenditure. According to Mr. A. Crosbie, of Wolverhampton, a rough estimate for the lime process would vary from 3s. 4d. to 5s. 6d. per ton of waste liquor. There would be something like 7~ ewes. of sludge from each ton treated. It is not 20