635

and cancer of the cervix uteri (10%) were commoner. A closerstudy of this observation should be given high priority.Workers from all countries reported a very high incidence of

cancer of the skin relative to other sites, and for the most partattributed the high incidence to actinic radiation. It is hard tobe sure to what extent the attack-rate for skin cancer is higherthan in Western countries, since it is clear that there is con-siderable underdiagnosis of some internal cancers.

Prof. E. SYMEONIDIS (Greece) emphasised the importanceof hygiene and circumcision in the prevention of cancer of thecervix, basing his arguments mainly on data from New Yorkand Israel. It is generally accepted that circumcision at 9 yearsof age as practised by Moslems is a less effective preventivemeasure than infantile circumcision; nevertheless it was

perhaps surprising that cervical cancer was the second com-monest cancer in Iran (as reported by Dr. Habibi).An important paper by Prof. H. RAHMATIAN and his

colleagues (Iran) was concerned with a high incidence ofoesophageal cancer in a population who chewed nass, a mixtureof tobacco, lime, and wood chips. Unlike chewers of betel-tobacco mixtures, the nass-chewers did not get cancer of themouth at the point where the quid was held. As Prof. H.DRUCKREY (West Germany) pointed out, this observation wasparticularly interesting in view of the recent discovery thatcertain synthetic nitrosamines selectively caused oesophagealcancer in laboratory rodents.

Prof. I. KANTEMIR (Turkey) reported the induction of skintumours in mice after the application of smoke condensate fromTurkish cigarettes. This went some way to showing that the

cigarettes prepared from air-cured tobacco were not neces-sarily less carcinogenic than those made from artificially dried(flue-cured) tobacco. Dr. F. J. C. RoE (U.K.) described experi-ments in which tobacco smoke condensate and particulatematter from London air were applied to mouse skin. Appliedseparately, both were carcinogenic. Applied together, theireffects were additive or even more than additive.

Though few experimental studies seemed to have been carriedout in the countries from which the chief representatives to thecongress came, a notable exception was the work of Dr. M.PAMUKCU (Turkey), who used mice in order to study theaetiology of cancer of the urinary bladder in cattle, which isunusually prevalent in certain regions of Turkey, especiallyalong a strip of the Black Sea coast. A high proportion of thecancers were hasmangiomas rather than carcinomas. Dr.Pamukcu demonstrated the presence of bovine skin-papillomavirus in some of the bladder tumours; but it was likely to havebeen present as a passenger rather than as a causative virus.Bladder cancer was especially prevalent in cows feeding on aparticular species of bracken. It also arose more often in miceafter the intravesical implantation of pellets containing materialfrom the urine of bracken-fed cows than in controls bearingpellets with urinary material from control-fed cows.The fact that the conference took place represents a

tremendous achievement on the part of many people. The

problems of cancer in the Near and Middle East present amajor challenge. High standards of scientific communicationand the use of the best epidemiological methods are pre-requisites to success.

Medicine and the Law

DEATH OF A RUBBER WORKERAT a resumed inquest in Bath on Sept. 17 the jury returned

a verdict of death from industrial disease on Reginald CharlesTayler, a rubber worker, aged 52, who died on May 10. Thecause of death was pulmonary embolism following total

cystectomy for carcinoma of the bladder. This disease wasfirst diagnosed in 1964, when investigation revealed multipletumours.

Mr. R. G. Room, group personnel manager of the AvonRubber Company, stated that Tayler had worked at the Avonfactory at Melksham since the age of 14, except for two periodsof Army service in 1930-34 and 1939-47. He agreed thatcertain antioxidants now known to be dangerous had been usedin the factory until 1949; these were ’ Nonox S ’, Nonox HF ’,and one consignment of ’ Santoflex BX ’. He agreed with thecoroner’s suggestion that there was a possibility that reclaimedrubber containing dangerous substances might have been usedin some firms after 1950. He said that from 1934 to 1937

Tayler was engaged in curing tyres; he received these tyreswith cured air-bags in them, and placed them in steam-heatedpresses. Nonox S had been used in the manufacture of the

air-bags, and Mr. Room agreed that fumes might havebeen released from the bags when the tyres were in the

presses.

Mr. Room agreed that on two occasions, in 1957 and 1961,the firm had been made aware by the health research unit ofthe Rubber Manufacturing Employers’ Association of the riskto workers who had been exposed to these antioxidants, andthat the Association had urged the firm to make use of theunit’s cytological screening service; however, screening was notstarted at the factory until March, 1965.

In reply to questions from counsel for the Avon RubberCompany, Mr. Room stated that had screening been started in1957 it was not certain that the deceased would have comewithin the scope of the scheme as then outlined, but he agreedthat in 1961 a wider measure of screening was urged. He saidthat the decision not to commence screening at this date was

his; if he had recommended to the board of the Avon Companyin 1961 that they should undertake screening, the board wouldhave agreed to do so. One factor taken into account in reachingthis decision was that in 1961 he knew of only 2 cases of thedisease, and both these were men who joined the firm after1950; he knew of no cases among exposed workers, and tookthis as evidence that no risk had operated. Another factorconsidered was the risk of arousing fear in the minds ofworkers if they were asked to undergo tests.

Dr. R. A. M. Case, of the Institute of Cancer Research,pointed out that Tayler was a comparatively young man to dieof this disease. He gave evidence about the mode of absorptionof the substances into the body, and explained that men couldbe exposed by merely being in the vicinity of processes involvingtheir use. The firm had used nonox S, nonox HF (whichcontained 5% of nonox S), ’Neozone HF ’ (which had thesame constitution as nonox HF), and santoflex BX, which wasbased on 4-amino diphenyl. He referred to the possibility of arisk continuing after the withdrawal of dangerous antioxidantsin 1949 through the use of reclaimed rubber containing them.

Dr. Case said that, on the basis of the numbers of workersstated by Mr. Room to have been employed at the factory in1954 and 1964, it was possible to calculate the number ofdeaths from tumour of the bladder that would be expected tooccur from 1955 to 1964 if no occupational risk were operating:the expected number of deaths among all employees was 2, andthe observed number was 7; the odds against such a findingoccurring by chance were 500 to 1. If the calculation was con-fined to men included in the Census definition of " rubberworkers " the expected number was 1-28 and the observeddeaths totalled 6, the odds being 1000 to 1 against. Dr. Casestated that he knew of 14 cases of bladder tumour amongworkers at this factory, and 3 of these were still living; it wasnot certain that all cases had come to light.

Dr. Case said that Tayler could have been exposed duringhis work with tyres and air-bags from 1934 to 1937, and to alesser degree afterwards. In his opinion it could be presumedthat Tayler’s death resulted from exposure at work to anti-oxidants now known to be dangerous. At the time these sub-stances were in use the firm could have had no knowledge oftheir dangerous properties.