Document pp9N6xb9K165mm28w29d3e3z6

/ Abstracts of papers submitted for publication or: the Mortality .itudy of Workers exposed to Vinyl Chloride Monomer. \ R&S 107248 By A.J.KOX and P.K.COLLIER Identification port iculars were obLnitv-d for over 7,000 men who wore at some time between 19^0 and 197^ exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride. Approximately 99% of these have been traced and their mortality experience studied. The overall standardised mortality ratio, 79-^ t shows a .significant reduction compared with the national rates. Four cases of liver cancer are found. Two of these have been confirmed by a panel of liver pathologists ns angiosarcoma and two as not angiosarcoma. There is no evidence supporting the hypothesis that cancers other than those of the liver are associated with exposure to vinyl ^ chloride monomer. The two cases of angio ;arcoma were found in men who * has been exposed to high concentrations although the second man died only ; eight years after exposure. The industry in Great Britain has expanded considerably since the second World War with over 90 per cent of men having entered within the last decade. Conclusions drawn about 'the influence of vinyl chloride monomer on the mortality experience of men in this industry must consequently be tempered by the reservation that the full impact may not yet be in evidence. (Submitted to the British Journal of Industrial Medicine) (B) LOW MORTALITY RATES IN INDUSTRIAL COHORT STUDIES DUS TO JELECTION TON WORK AND SURVIVAL IN THE INDUSTRY By A.J.KOX and P.K.COLLIER Occupational groups are often described as relatively healthy because their mortality rates are lower than the national average. Although correct this confuses the issue for those interested in assessing the effects of exposure to a particular chemical. By a further annlvsis of data collected in a study of all nen over exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride in Great Britain, three factors h'-ve been shown to contribute to the low mortality rates that were observed. The three factors, the selection of a healthy population for employment; the survival in the industry of the healthier men; and the length of time that this population has been pursued, have all been quantified. The mortality experience within five years of entering this industry was shown to be as low as 37 per cent of that expected; for circulatory disease and respiratory disease as low as 21 per cent. There was a progressive increase in standardised mortality ratio with the length of time since entry such that the effect had almost disappeared 15 years alter entry. To avoid confounding the selection effect with the survival effect the latter was measured by separating men who survived 15 years after entering the industry according to whether or not they were still in the industry after this period. Those who had left experienced an overall standardised mortality ratio some 50 per cent higher than those still in the industry. This effect although consistent in irer Ge groups between 25 and '/li und all cause groups studied was greatest in those aged between <?5 and Vi and for lung cancer and respiratory disease. (Submitted Lo the British Journal of I'rovenLive and Gociul Medicine) COPIED BY MCA FOR DISTRIBUTION TO THE VINYL CHLORIDE TECHNICAL PANEL, AH^UST 27, 1976, MR. M. FREIFELD 1 ) R&S 107249 v-1 1976 J ` I, '"'V i' y' ' . ' *. - "y * fn -* fc ' ' yi *` i (') * * .. ` . ** . * i , ^ .* "A y \*`r ** X "\ . -vA 1 * I ' ' ` t."M 4 3 i ' * ITEM 3 (a) COPIED BY MCA FOR DISTRIBUTION TO THE VINYL CHLORIDE TECHNICAL PANEL, AUGUST 27, 1976, MR. M. FREIFELD mt i tscn, may 15, 1976 / 1079 * S1 60 UJ 58 54 62 64 66 68 70 72 Mother.E -rosettes (%) Fifl. 2--E^rovcttlfig cll* In 11 mod)Cf*btby pair*. / / p<0-001, paired c test). For the E-rosetting cells the mean for the mothers was 68-3% (s.D. 2-9%) and for the babies 61-9 (j.D. ? 7%). This dilfcrcnce too is significant (pcO-OOl) and the correlation codficiem is also significant (r=0-74, p<0-005) (fig-2). .r The E rosettes in the mothers ranged from 63% to,72%. We had no counts of less than 50% and cannot calculate in the same way as Halbrccht and Komlos, but our counts for the babies ranged from 58% to 65% which is higher than their figures and nearer the mean of 53% reported by Campbell et al.1 and Steel ct al' There is considerable variation in li-rosettc counts due to technique. We used the method described by Stjemswiird et al.* In testing each mother and baby's cells together, however, variation due to technique should not greatljl affect the ratios. The normal range of T cells in newborns is probably wide. However, our findings suggest that there is a direct relation ship between the number of E-rosetting cells in some mothers and their babies. Since these cells are the major subpopulation of peripheral-blood lymphocytes, it is likely that the correla tion between the total blood-lymphocyte counts is largely due to the correlation between the E-rosetting cells (T cells). This raises the possibility that these cell populations in the fetus are regulated by maternal factors. Htiwh OitMrcn`t Hotpiul, ^V.whc4rr M9 1AA Murvjrn Mmpilll, lSMH ftj) < hfiMic llmpitul und llolt Katlmm Inititiiir, WauiheMcr M2<) 91tX D. I. K. Evans N. Vyramuthu M. Palmer GENETIC RISKS OF VINYL CHLORIDE Sir,-- Ilic assertion in the paper by Dr Infante and his col leagues (April 3, p. 734) that "a significant excess of fetal loss was observed among wives following exposure to v,c.m." is such as to have iiisufied much more complete presentation. Anv assertion. vA vmh importance should at least be supported bv a specification ol the methods at data collection, and a tabu lation of the raw data before analysis. 1 laitHAs'll .11 . '\ ji:. r, C , \V0,-1, 1, Avn.lc, (,nxn. A . 5 u, 1 i'hn cip htttiikH l^"4, IS, Slttl, t.. M., I-.HOJ, J.. .Smith, M. A. Uactt, 1975, i, *14. 1. Sticnwftitra, jotMisl, M,, Vailhy, 1;. Wir/cU, H.* Scaly, R. ihi4. 1972, i, 1352. 1 he subiect being spontaneous abortion, the use of a ques tionnaire, and the ensuing low response-raies, can be viewed sympathetically, but must detract from the accuracy of the study. I he data are presented only after an age-ad|ustmeru procedure which behaves very misleadingly. A crude percent age of 10-1 for a sample whose average age is 26-4 is ad|ustcd violently downwards to 6-1, while a figure of 16-5 for a sample of average age 30-2 is only reduced marginally to 15-8. Pre sumably the adiustmem is being done within the study and the small sample size is the cause of this anomaly. It would have been better to have adiusted all the figures in accordance with national figures, but perhaps, in such a delicate area, such stat istics arc not available or arc unreliable. It/is to be hoped ihat the complete study will be published without delay, with the above omissions rectified, so that it will 7be/possible to put this, at present isolated, question in context. Central Medical Group, Imperial Chemical Induitncv AX ilmiiow, Cheshire SK9 1QII G. M. 1'addlf SOCIAL STIGMA AND TUBERCULOSIS Sir,--You have stated1 that "Within the U.K. tuberculosis is no longer feared. It is widely known to be curable with little inconvenience to the patient and it carries little, if any, social stigma". Personal experience in Belfast showed that fear still existed in some patients before their disease was explained to them. Because of this we have tried to find out if social stigma still exists. We asked 32 patients with pulmonary tuberculosis and 31 controls with other chest diseases of similar age, sex, and social background, about their attitudes towards their disease. In the tuberculosis group only 2 of the 13 with a family history of tuberculosis and 7 of the 19 without such a history knew that it was still possible to develop the disease in Belfast. In fact, there are at present about 100 new cases notified each year in ' a population of 600 000. Only 17 of the 32 patients with tuberculosis knew that their disease was infectious. 2 university students were among the group who did not know. A similar proportion thought the dis ease was in some way related to an inherited weakness of the chest. Both the tuberculosis group and the control group were asked if they had any sense of shame or similar emotional feel ings because of their illness. 5 of the 31 control patients expressed feelings of inferiority, shame, embarrassment, and a sense of social isolation. These were all related to specific physical disabilities such as cough, sputum, or dyspnoea. 12 of the 32 tuberculosis patients described feelings of shame, in feriority, and a fear of social ostracism. None of these attitudes were related to specific physical complaints. The interview with another patient was cancelled due to obvious embarrass ment and shame about discussing the disease. An additional 4 from the group of tuberculosis patients although not sufTering from a direct social stigma about the disease expressed a sense of guilt and shame at the reflection of their life style, These pa tients were mates who had been heavy drinkers with families, although none were alcoholics. Improved social conditions here in the past helped to reduce the incidence of pulmonary tuberculosis. However, in many large cities there is increasing alcoholism, overcrowding, squat ting, and drug taking, as well as an increase in the numbers of old people. Such features may arrest the downward trend in notifications of the disease. If the lack of knowledge about tuberculosis and the continued social stigma (not just in elderly patients) exist in other areas of the U.K. then perhaps now is the time to increase public education about a prevenrab1-- and curable disease. l-or.tcr tinffl tfinpual, BciftBM4HD John Cumrion , I ,, Frld Stanford I. Lmti, 1975,11,593. _