870

This is but an example of the matters which remainto be dealt with. They are details, and only detailsby comparison with the arrival of a great centralscheme, but there will be room in their adjustmentfor the display of adequate leadership, and it is nottoo soon to give them consideration.

PULMONARY ASBESTOSIS.THE introduction of that extremely useful substance

asbestos into industry has unfortunately given rise toa new occupational risk and to yet another form ofchronic pulmonary fibrosis. The material has in one:form or another been known since the days of Greekand Roman civilisation-the ancient writers referto it as " unquenchable stone "-and CHARLEMAGNEis said to have had a table-cloth made of it, whichwas cleansed by throwing it in the fire. In earlierdays the hornblende variety of asbestos was oftenreferred to as amianthus. Sir THOMAS BROWNE, the.author of Religio Medici, in one of his poems sighsthat he might have amiantine toes which would notsuffer from the gout. The indestructibility ofasbestos has no doubt been the primary reason for itsintroduction into trade processes ; asbestos willresist great heat, strong acids, and alkalis, whilstowing to its fibrous structure certain varieties of itcan be carded and spun like a textile. A reportl justpublished by the Home Office deals with the effectsof asbestos dust on the lungs and on the dust suppres-sion in the asbestos industry, and is written by Dr.E. R. A. MEREwETHER and Mr. C.W. PRICE, respectivelymedical and engineering inspector of factories.Dr. MEREWETHER’S report is based upon data obtainedin an extensive investigation made during 1928 and1929, initiated by the Home Office, following thediscovery of non-tuberculous fibrosis in the lungs ofan asbestos worker, of sufficient severity to necessitatetreatment in hospital. Prior to this the Home Officehad knowledge of only two deaths in which theinhalation of asbestos dust was a contributory cause ;a survey of the industry in 1910-11 had not revealedany serious hazard. The well-known triad-exposureto dust, fibrosis of the lungs, and high mortality-ratefrom pulmonary tuberculosis-has long been recognisedin industrial processes involving the use of free

- crystalline silica, but, as Dr. MEREWETHER remarks,the fact that a serious, even fatal, degree of fibrosis canbe produced by other dusts has not been generally.appreciated. A peculiar feature of the fibrosisproduced by asbestos dust is the occurrence in thesputum or lung-juice of bodies, described by Prof.MATTHEW STEWART, which have a curious resemblanceto a minute crustacean.2 These consist, as BURTONWOOD and GLOYNE have shown, of a series of discs.around a central spicule of asbestos.The manufacturing processes fall into one of two

groups according as they employ (more or less)pure asbestos and asbestos along with other dustysubstances. The former group has been the subjectof this inquiry on the ground that the effect ofasbestos dust alone must be worked out before thecomplicated factors can be assessed. The popula-tion at risk in this group of the industry is not exactlyknown, but is estimated at 2200. A certain amountof selection was used in the examination, new-comersand long-time workers being chosen. The men

examined were with one exception at work on theday of examination ; their number (excluding 11 caseswho had previously worked in other dusty occupations)

1 H.M. Stationery Office. Pp. 34. 1s. 3d.2 THE LANCET, March 1st, p. 445, and March 29th, p. 701.

was 363, or 16.5 per cent., .of the estimated totalworkers in the industry. Of these, 95 (or 26-2 percent.) showed a diffuse fibrosis of the lungs attributableto the inhalation of dust ; 21 others had precursive signsof the disease. In 133 cases radiograms were made;62 of these showed definite diffuse fibrosis, 25 wereonly suggestive. Dr. MEREwETHER is careful to

emphasise the fact that only a proportion of theworkers have been examined and that it would beunfair to assume that roughly 1 in 4 asbestos workershave fibrosis ; the group examined was loadedwith a high proportion of men who had been fiveyears or more in the industry. The actual figureswere these. There were no cases of fibrosis amongthose who had been employed less than 4 years,36 cases in those employed from 5-9 years, 27 casesin those employed 10-14 years, 15 cases in those

employed 15-19 years, and 17 cases in those employedover 20 years. Considering the relation of fibrosisto age the largest number of cases were found inthe age-groups 30-39 and 40-49 ; Dr. MEREWETHERdeduces that the important factor is the length ofexposure, and that the age factor is negligible. Thedifficulties in ascertaining the incidence of fibrosisamongst workers in particular processes seem insur-mountable as many processes are housed in one roomand workers are transferred from one process toanother. But there is clearly a lower incidence andprobably a later onset among the spinners as a groupthan among those who crush, card, or weave asbestos.No evidence was found to indicate that one varietyof asbestos is more potent than another in producingfibrosis. Concentration of dust and length of exposureare interdependent factors. For a number of yearsdisablement, it seems, is curiously slight, even more sothan in the case of silicosis. This may be due in part tothe character of the disease, and in part to the fact thatthe work is not as a rule strenuous. The affectedworker often continues at work with occasionalbreakdowns from bronchitis until he his aware ofshortness of breath upon exertion. A terminal

broncho-pneumonia or other acute infection maysupervene while the man is still at work ; with othersthere may be a period of invalidism. Particulars aregiven of ten cases up to the end of 1929 in which anadvanced degree of abestosis without tuberculosiswas the primary cause of death, nine being verifiedpost mortem. The length of exposure in these casesvaried from 9 to 24 years. The rate of progressseems to vary within wide limits. With continuedexposure to high concentrations of dust the fibrosismay be fully developed in from seven to nine years ;with a lesser the fibrosis may take 15 to 25 years tomature. So far as the available data go there is nospecial liability to pulmonary tuberculosis amongstasbestos workers.

’

Preventive measures are dealt with by Mr. C. W.PRICE in the second part of the report. The factoriesand workshops concerned number at least 160, ofwhich 18 are textile factories. Small premises arethe rule. The majority are well-housed and well-ventilated, but there are some open-sided shedswhich are difficult to keep clean, and some which arecongested with material. The arrangements forventilation vary much. Dust removal systemswhere used effect a measure of general ventilation;over-head extracting fans are unsuitable and littleused. Extraction by downward displacement has beenconsidered for weaving rooms and Mr. PRICE considersit might, with suitable safeguards, replace thelocalised exhaust ventilation, although it could not besuccessful without efficient heating. While verydusty processes are already recognised, he points out

871

that in processes such as spinning and weaving, inwhich in other textile trades special methods for dustcontrol are not required, precautions must also betaken in asbestos works. The manufacturers are

clearly confronted with the necessity of attainingconditions which will ensure much less dust in the

atmosphere than can be tolerated safely in com-

parable trades not using asbestos. The recommenda-tions in the report include the application of efficientlocalised exhaust ventilation at dust-producingpoints; the substitution of enclosed mechanicalmethods for hand conveyance, and for dusty hand-work generally ; the effective enclosure of dust-

producing machines and plant ; and the substitutionof wet methods for dry. Young persons shouldbe excluded entirely from specially dusty work.

STATE MEDICAL SERVICE.THE objects of the State Medical Service Association

have been revived in the National Medical ServiceAssociation, the constitution of which was adoptedlast week at a meeting held at the House of Commonsby invitation of three medical Members-namely,Mr. SOMERVILLE HASTINGS, Dr. ALFRED SALTER, andDr. ETHEL BENTHAM. Membership of the newAssociation is to be open to all registered medicalmen and women and dentists, to registered medicaland dental students, and to others who are in

sympathy with its objects. The primary aim isto advocate and make clear to the medical professionand to the public the advantages of a national medicalservice, and for this purpose it will hold publicmeetings, publish and circulate literature, andotherwise promulgate its cause. The Associationwill also take steps to promote and secure legislationgiving effect to its objects. In a footnote to theconstitution it is stated that a national medicalservice should include the establishment of a medicalservice available to all members of the communityand providing every necessary form of medical,surgical, obstetrical, dental, and preventive treatment,coordinated as one service under the Ministry ofHealth. It will be recalled that these were sub-

stantially the aims of the State Medical ServiceAssociation founded in 1912 with the late Prof.BENJAMIN MooRE, F.R.S., as president, Dr. JANEWALKER as hon. treasurer, and Mr. CHARLES A.PARKER as hon. secretary, the activities of whichwere overshadowed by the coming of the war. ThisAssociation was founded because its promoters feltthat the time had come for freeing a large sectionof medical men and women from the distasteful and

incongruous task of assessing and collecting feesfor services rendered ; in its stead they should beguaranteed an adequate and certain salary duringtheir active years of service, coupled with a systemof gradual promotion and followed by a generouspension. LTnder such a scheme the present hospitalsystem would be placed, it was urged, on a firm financialbasis, hospital staffs being properly remunerated andhospital doors opened to all sections of the community.The scheme was frankly described as the organisationof the medical profession as a branch of the nation’scivil service. The new Association has, we understand,as yet gone little beyond the drafting of its constitutionand acceptance of the principle that an efficientmedical service can only be built up if the doctorswho are serving in it are allowed a large say in theconditions of service. Its promoters feel that thetime has come for the State to accept responsibilitynot only for certain special affections such as tuber-culosis and venereal disease, but for the provision of

efficient treatment for all who require it. There is, how-ever, nothing of the reforming bigot about them, andthere is no suggestion of placing all doctors underGovernment control while improving, from the publicpoint of view, the medical activities of the State.

Annotations... Ne quid nimis."

PATENTS FOR FINE CHEMICALS.IN summarising the report of the British Science

Guild on the British patents system, we commentedon it from the point of view of the medical inventor.lIn a recent address to the Society of ChemicalIndustry2 Mr. F. L. Pyman speaks from the pointof view of the manufacturer. He points out thatchemical firms incur enormous expenditure whenthey undertake the research which leads to thepreparation of new or improved substances. It isnot unreasonable for them to expect a temporarymonopoly of the drugs which are discovered throughtheir enterprise. In the absence of a monopoly theyhave little incentive to market the product. Dakin’ssolution, for instance, is a valuable antiseptic whichis little advertised simply because it was not patentedand can be manufactured by anybody. Supposingthat a manufacturer prepares all the many possiblederivatives of a certain drug which has purgativeproperties, and eventually finds one which is an

efficient purge and is at the same time free fromobjectionable actions. If he puts this substance onthe market under a registered name-the "

some-

thing brand " of the drug-other manufacturers willspeedily market it as the " something else brand."If he sells it disguised as a constituent of an undeclaredmixture the medical profession will be prejudicedagainst it. The only other course open to him is tokeep his knowledge to himself and try to find someallied substance with a similar action " new " enoughto be patented. Obviously, Mr. Pyman concludes,an adequate system of monopoly patents is essentialto the manufacturer as an incentive to research,to the marketing of products, and to the disclosureof processes.Mr. Pyman welcomes the proposals of the British

Science Guild as a means of protecting " biological "

products without infringing the ethical code of themedical profession, but is not at all so sure of theirvalue for " chemical " drugs.

" Dedicated " patentsmight well protect such inventions as " quinanil "and thyroxin, but a patent is in effect a reward fordisclosure, and the manufacturer cannot be expectedto disclaim the reward in the way that the medicalresearch worker is expected to do. If the manufac-turer cannot patent the fruits of his enterprise inendowing research he will try to keep his processessecret. Mr. Pyman instances the case of histamine,the activity of which was demonstrated in 1910. Soonafterwards Mr. Pyman devised a new and improvedsynthesis which was patented by Mr. Wellcome andhimself. If the employing firm had been able toobtain only a patent which they could not controlthey would have had no inducement to allow Mr.Pyman to publish his method, and he feels that theresult of substituting

" dedicated " for monopolypatents will be to restrain the patenting of improvedprocesses for the manufacture of known compounds,and consequently to hinder the publication of scientificwork. Moreover, as he points out, chemical inventionsoften proceed step by step, and the manufacturerwho cannot obtain a monopoly for his drug willendeavour to protect some intermediate productessential for its synthesis. He advises all interestedparties to scrutinise very carefully the proposedchanges in the patent system before they are allowedto pass into law.

1 THE LANCET, March 29th, 1930, pp. 698, 718.Jour. Soc. Chem. Industry, March 21st, 1930, p. 151.