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ignored by the hospital management committees. This

neglect of professional opinion has been mainly confinedto regional hospitals, for the boards of governors of

teaching hospitals have usually listened very carefullyto the advice of their senior medical staff.The original instructions from the Ministry, issued in

1948, advised that there should be committees represen-tative of different groups of staff, but no emphasis atall was placed on the real necessity for senior medicalstaff committees. The new memorandum makes goodthis omission and clearly states that, in addition to groupmedical committees, individual hospitals of appropriatesize should have medical staff committees, normallyincluding the whole senior medical and dental staff.Such committees, the memorandum suggests, shouldconsist of up to 30 members, from which a small executivesubcommittee might be appointed. Their object is toadvise the hospital authority on all medical matters andquestions of medical administration. They should keepthe hospital facilities under continuous review to ensuretheir most effective use ; and they should not confinethemselves to matters specifically referred to them.The memorandum mentions some examples of the widerange of subjects on which the committees could giveregular and valuable help to hospital authorities :

(a) developments in the scope of a hospital’s work, such asthe formation of new departments, or extensions and modifica-tions in existing departments ;

(b) allocation of beds ;(c) criteria to be followed in deciding upon the admission

of patients on the waiting-list ;(d) arrangements to be adopted for emergency admissions ;(e) procedure for dealing with complaints involving medical

or dental staff ;(f) procedure for making appointments of junior medical

or dental staff (within the framework of such central guidanceas has been given--e.g., in relation to registrars) ;

(g) types of medical and dental equipment and supplies tobe obtained ;

(h) care of medical and dental records ;(i) economies to be sought both generally and in relation

to such matters as prescribing and use of X-ray films ;(j) control of infection in hospitals ;(k) recommendations of members of the staff to serve as

members of the board of governors or hospital managementcommittee ; and

.

(/) the organisation of such activities as clinical demonstra-tions or maintenance of a medical library.These committees, the Ministry thinks, should alsoundertake the statistical review of the clinical work ofthe hospital, and the discussion of these analyses wouldbe a valuable means of maintaining a high standard ofclinical work.Many of these activities are, of course, already covered

by existing medical staff committees, most of whichhave continued to function, even though subjected toadministrative pinpricks and rebuffs. But this officialrecognition of their existence and value will neverthelessprovide a timely impetus. We hope that the consultantswill respond to this recognition by giving renewed supportto their administrators in dealing with the difficultiesof the present financial situation.

HAZARDS OF PESTICIDES

Ix his war against Nature man sometimes finds hisguns spiked or trained against himself : in the sphere ofantibiotics he is growing accustomed to such reverses.In agriculture he now uses a large number of poisonoussubstance--insecticides, antiparasitics, molluscocides,rodenticides, and herbicides-to protect growing crops,seeds, and stored food against their natural predators.As result he himself is exposed to these pesticides in hisroles of producer, disperser, and unwitting consumer.Increasing concern has been felt over the possible dangersof pesticides to man, and the fourth World Health

Assembly called for an investigation of the problem.Dr. J. M. Barnes has now drawn up a report on behalfof the World Health Organisation. This is a reassuring,though by no means a complacent, document, whichwill allay anxiety without decreasing vigilance.The pesticides presently in use range in toxicity from

the harmless vegetable substance pyrethrum, through theslightly toxic chlorinated hydrocarbons such as D.D.T.and the garnrna isomer of benzene hexachloride (’ Gam-mexane’), to the poisonous organo-phosphorus anti-cholinesterase compounds such as tetraethyl pyro-phosphate (T.E.P.P.) and parathion. This last grouppresents the manufacturer with the problem of producinga toxic substance without dangerously exposing theworkers, but there is little ground here for anxiety ;with suitable plant still more toxic substances could beharmlessly manufactured. Workers in formulating plantsmay face a more significant hazard. To reduce the costof a pesticide it is usual for the active ingredients to beappropriately mixed and diluted in small works near theplace of use. The number of active ingredients used isless than fifty, but in California in the year 1950 aloneno fewer than 9454 approved formulated products wereplaced on the market. Canada, the United States, andseveral European countries have adopted a system ofcompulsory registration of such products. This ensuresthat the product is reliable, and that it is so labelled thatthe farmer can use it safely and effectively. Registrationmight also be a means of ensuring regular inspection ofthe formulating plants ; for it is in these plants, some-times small, simply equipped, staffed by unskilled labourhandling unfamiliar compounds, that accidents haveoccurred from undue exposure of the workers. It wouldseem that the registration system should be universallyadopted.

In California, where pesticides are very extensivelyemployed, much of the application is done by firmsengaged wholly in such work. This means that smallnumbers of workers are much exposed, but allows theuse of safe machinery and methods and suitable medicalcare. Spraying from aircraft is popular ; in 1951,2,900,000 acres of California were treated in this way.This is the safest method of all, although, because ofunsatisfactory equipment, exposure of pilots and loadersto pesticides has accounted for a few accidents. Aircraftare now being specially designed for this task.What of the exposure to pesticides of " third parties

the remote consumer of treated crops ? There is littledoubt that such exposure does occur, and the U.S. PublicHealth Service have found measurable quantities ofD.D.T. in the fat of sailors who have never to their

knowledge come in contact with that substance. Barnesstates emphatically that there is not a scrap of evidencethat such traces of pesticides give rise to disease ; buthe points out that the possibility has by no means beenexcluded. There is no evidence, for instance, that, say,chlordane causes cancer. But before we can be sure thatit does not, we must have the following, which we lack :a method of estimating the degree of exposure of workers ;a simple chemical test for analysing the degree of con-tamination of food samples ; details of the mode ofaction of this pesticide and of its behaviour in the humanbody ; and above all accurate statistics of the incidenceof cancer in its different types (and of other diseases aswell) in heavily exposed persons compared with suitablecontrols. It is a little disturbing that people will continueto be exposed to this and other pesticides for many yearsbefore the required information is available. Further-more new pesticides are customarily introduced into wideuse on the basis of short toxicity studies on small

laboratory animals, and without real knowledge of their

1. Toxic Hazards of Certain Pesticides to Man. By J. M. BARNES.World Health Organisation, monograph series, no. 16. Geneva,1953. 7s. 6d.

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effects on man. Barnes sees in these problems the needfor much further research, and for more care in theuniversal release of new pesticides.

Despite these disadvantages Barnes has no doubt aboutthe continued use of pesticides. Without them it wouldnot be possible to grow enough cheap food for a hungryworld. The ideal alternative-biological control of pestsby crop breeding, rotation, manuring, and so on-isnot, nor is it likely to become, practicable. The reportshows that the hazards to man from the use of toxicpesticides are slight indeed, and are a price that it isjustifiable to pay for the immense benents that theyyield. But the report also shows the need for moreresearch, more legislation, and greater vigilance.

1. Lowe, J., McNulty, F. Leprosy Rev. 1953, 24, 61.2. Cummins, S. L., Williams, E. N. Brit. med. J. 1934, i, 702.

LEPROSY AND TUBERCULOSIS

Lowe and McNulty’s review of work on the immuno-logical relation between leprosy and tuberculosis is

timely, for in many of the areas where the W.H.O. planfor B.c.G. immunisation is being put into action leprosyis also a serious problem. They have studied the tubercu-lin and lepromin sensitivities of various groups in Nigeria.They used a purified tuberculin at a final strength of 50international tuberculin units (equivalent to 0-1 ml. of1 in 200 Old Tuberculin). Lepromin is a heat-sterilisedsuspension of Mycobacterium leprce obtained from leprousnodules. Each batch has to be standardised in man and0.1 ml. of an appropriate dilution is used intradermallyin the test. Almost all sensitive individuals produceboth an early Fernandez and a late Mitsuda reaction.The early reaction is read at forty-eight hours andconsists of erythema and cedema round the site of theinjection. The late reaction, which was used by Loweand McNulty, is easier to read in dark-skinned people,and consists of a nodule at the injection site present inthe third or fourth week. Early work had shown that thetest was not specific for M. leprae infection and that ahigh proportion of positive tests may be found in placeswhere there is hardly any leprosy. Cummins andWilliams,2 for instance, in an investigation in Wales,tested 25 people and found them all sensitive.Lowe and McNulty found a significant agreement

between the lepromin and the tuberculin test in normalchildren and adults. Since lepromin-positive cases ofleprosy are not always tuberculin-positive, and sincelepromin and tuberculin tests show the same agreementin areas where there is no leprosy, the inference is thatinfection with tubercle bacilli may confer leprominsensitivity as a cross-reaction. This conclusion is

strengthened by Lowe and McNulty’s observation thatonly weak tuberculin reactors are lepromin-negative, and,more conclusively, by the finding that B.C.G. vaccinationinduces both sensitivities. They vaccinated a group of65 people and 64 became tuberculin-positive. Of these65, 7 were already lepromin-positive, 40 became positiveafter vaccination, and another 14 showed doubtfulreactions.The question remains whether lepromin sensitivity,especially that induced by B.c.G., indicates an increasedresistance to leprosy’! Unfortunately the evidence is

scanty. Experienced leprologists use the test as a guideto prognosis. It is usually positive in the benign tubercu-loid cases, and almost invariably negative in the seriouslepromatous ones. The lack of resistance is thought tobe due to a failure of immunological mechanisms reflectedin the negative lepromin test.The results of tuberculin tests in lepers did not support

the idea that natural tuberculous infection increasesresistance. Both types of lepers had lower rates oftuberculin sensitivity than the general population, but therate was slightly lower in tuberculoid cases, and therewas little agreement between the two tests. Moreover,

tuberculosis is a. common intercurrent disease in leproma-tous leprosy, and quite often it is the cause of death.When B.c.G. vaccination was attempted in a group oflepers, there was little change in sensitivity in thosetuberculoid cases that were already lepromin-positive.84% of the lepromatous cases became tuberculin-positive,but only 10% became lepromin-positive, although another30% gave doubtful reactions. These results demons.trated that the lepromin insensitivity of the lepromatouspatient is not absolute, but that he is less readily sensitisedthan a normal person. There was no striking benefitnoticed in the patients who became lepromin-positive;but assessment was hampered by the concurrent use ofchemotherapy and the short interval that had elapsedsince B.c.G. vaccination.

Altogether there is no reason to suppose that B.C.G.vaccination is the answer to leprosy. On the other hand,it would be worth conducting a controlled trial of itseffect in an area where leprosy is endemic ; but, as Loweand McNulty point out, this must not be allowed tointerfere with other proven methods of control.

1. R.H.B.(53)55: and appendices A and B.

STATIC ELECTRICITY IN THE THEATRE

ANAESTHETISTS who use explosive gases are now

studying the risks more closely ; for anaesthetic explosionsare apparently becoming commoner. The electricalsafety engineers appointed by the Ministry of Healthfind that " the largest single agent of ignition " is staticelectricity, and the interim advice contained in recentmemoranda to hospital authorities 1 deals particularlywith this hazard. The risk can be reduced in three mainways : avoidance of materials likely to generate staticelectricity ; maintenance of humidity ; and provision ofmeans for discharging static electricity.

Of materials, the worst culprit has been rubber-thatis, the ordinary, insulating sort-and the use of theconducting, antistatic variety is an important safeguard.Such rubber is now available in sheeting, aprons, tubing,wheel tyres, footwear, and many other sorts of equipmentlikely to be needed in an operating-theatre. But careand thought are needed if its virtues are to be effective.There must, for example, be complete electrical continuitybetween the patient and the metal framework of theanaesthetic machine and thence through the floor to

earth ; and each link in the chain must be considered.Each item of antistatic rubber should be tested forelectrical resistance before use and at three-monthlyintervals. Not only do the different makes vary butelectrical resistance increases with use. Any item inwhich this exceeds 100 megohms should be withdrawnfrom use. A value below 50,000 ohms, on the otherhand, increases the risk of shock and fire. It is thus quiteinsufficient to rely on the black colour of antistatic rubberequipment ; each piece should be clearly marked, and arecord kept of the routine tests on it. One disadvantage ofthe material, so far, is some loss of pliability as comparedwith ordinary rubber; breathing-bags made of it are alittle stiff, and tubes do not grip metal connections sowell. Furthermore, precautions must be observed whenit is used with surgical diathermy.As to humidity, this is an unreliable safeguard, and

the sense of security which British anaesthetists have feltin their climate is apparently unfounded. Humidity shouldbe kept at 55-60% where there is special equipment forproducing it ; atmospheres more humid than this areoppressive. In the absence of special equipment the theatrefloor can be damped at intervals. Breathing-bags and tubesmade of ordinary rubber should be damped before use.The third safeguard-means of discharging static

electricity-requires vigilance in maintaining a pathwaybetween earth and all persons and objects likely to beendangered. For the soles of footwear and- for -the floorcontacts of apparatus, antistatic rubber is the best