Document Xzrzrw36QVeNz6wd44pNGxJKG

GB/EMT MRC IhieumocoMloals Unit DOCtMRT A 22nd July 1975 BOMS Asbestos SUmi 'l Sub-Committee 1 UA Study Updating The original study carried cut by Dr. Knox consisted of 290 men who had worked at TBA for 10 or more yeara eince I. 1. 1933 and were etlll employed on 30. 6. 66. Thle population was updated by Dr. I.ewlneohn to 31. 12. 72. The period of service criteria remain the same but a man leaving TBA or dying after 30. 6. 66 would not ba excluded. That la Lewinsohn'a 1972 popn. Knox's 1966 popn. + men reaching 10 years' service between 30. 6.66antfil.12.72 Irrespective of whether they were still employed on 31. 12.72. The revised population contained 393 men. but one was excluded because it was discovered he had not 10 years' service and for another it proved Impossible to diaentangle his work history from another man with the same name, leaving 391 men. Data X-rays The latest x-ray of ehch man was used. For men who had left TBA Dr. Lewinsohn tried to trace them and invite them for a medical check up and x-ray. Be was successful In about 60% of the cases. The distribution of year of x-ray la:- 1951 .1959 1*964 1965 1966 - 1967 1968 1969 1970 1971 1972 1973 1974 1975 Total 1 *2* *3* 11 6 8 9 7 11 44 197 63 27 2 391 These x-rays were all read using the llO U/C classification by 4 readers (Dro Oilson. Harries, Lewinsohn and sprlngctt). 2. Other medical Hat*. For each man there wn* ; t dlcal carried out by Or. t.c.tlnaohn [or Dr. Kno::). 'V*v r -** vry'M ' nr* done rt ntmut the aanie time as the x-rays. From the medical* two Heins of Information were extracted: (I) presence or absence of creps. (II) whether the M.O. suspected asbestosis, and if so date of first suspicion. Also If a man had been compensated by the panel, the date ot compensation and rate of disability is known. Lung function data. The following are available on the number of men Indicated, ffv, FEV.and FVC'+' *- FRC TLC and RV PaCO. 319 304 302 286 TL 301 and also for everyone the race, smoking habits, height and weight. Works history and dust data. The work* history was coded using the FMAS list of job codes for the asbestos Industry. However, Dr. Holmes did not consider this detailed enough for him to link dust measurements. Therefore Dr, Roach viaited TRA in March 1975 a id produced a jib history using the codes used within TRA. He also established the locations corresponding to each job code and hence produced the average dust concentration for each job and each year from 1961 to 1972. The best way of estimating dual concentration* for thejobs prior to 1961 will have to be decided. Propoaed Analysis a-,_ The following.response variables will be considered:* Profusion of.small opacities (average of 4 readers) Profusion of small opacities (average omitting Dr. Lewlnsohn) Extent of opacitiee. Coatrophrenlc angle. Pleural thickening. Creps. Asbestosis suspected by M.O. Lung function data (? which). The following meaeures of exposure to aabestos:- Cumiilatlve time weighted doec. Cumulative dose weighted by time sinre deposited. Years sinre first exposure and various characteristics will be allowed for, e.g. age nnd height when analysing KEY etc.