Document zbvyp2RDNBOVx7EexRjoVa4Zg

HFM - 003517 TABLE 1 Deaths among 17,800 asbestos insulation workers in the United States and Canada January 1,1967-January 5,1977 -"5 > Number of men Man-years of observation 17,800 166456 Expected* Observed Total death!, all catisss Total cancer, all dtas Lung cancer Pleural mesothelioma Peritoneal mesothelioma Cancer of esophagus Cancer of stomach Cancer of colon-rectum All other cancer Asbestosis All other causes 1460.96 319.90 105.97 7.01 14.23 37.66 154.83 1,351.06 2,270 994 485 66 109 18 22 69 235 162 1.114 ^Expected deaths are based upon white meie ape specific mortality data of the U.S. National Center for Health Statistics for 1967^1975 and extrapolation to 1976. These are rare causes of death In the general population. The membership of the International Association of Heat and Frost Insulators and Asbestos Workers, AFL-CIO.CLC, was anroUad onJanuary 1. 1967, and has been observed since. oiutrate that enough asbestos exposure has occurred to produce such changes. In this sense, they are harbingers of future risk of clinical disease. Thbles 2-5 illustrate the characteristic latency of asbestos disease. In one group o? l,li7 asbestos insulation workers in the New York metropolitan area, most of 725 workers with less than 20 years from on set of exposure (Thble 2) had normal Xrays. When changes were present, they were minimal in extent. On the other hand, after the 20-year point, most X-rays were found to be abnormal, frequently exten sively so.4 Tables 3-5 show that few meso theliomas and little excess cancer of the',, lung occurred less than 20 years from on-" set. Most occurred 30 or more years from: onset of exposure. A young man may be gin work at the age of 18; his risk of as bestos-associated cancer does not become: substantial until he Is 40,50 or older. EARLY STUDIES: MESOTHELIOMA IN SHIPYARDS In 1968, the First warning that asbestos f*&01 6^18 4-A CANCER JOURNAL FOR CLINICIANS Onset of (vrs.) 40+ 30-39 20-29 10-19 0-9 TABfcE2 X-ray changes in asbestos IntylatiQn workers4 No. 121 194 77 379 346 Norma} 5.8 12.9 27.2 55.9 89.6 Abnormal 94.2 : 87.1 72.8 44.1 10.4 Asbestosis (grade) 1 23 35 51 26 102 49 18 35 17 4 158 9 0 36 0 0 . Total 1,117 51.5 48.5 366 126 60 disease might be a serious problem in of 1946rl976, total employment remained shipyards was sounded by Harries:in in this range, fluctuating with economic Great Britain and Stumphius6in theNeih- conditions and the country's shipbuilding erlands when they reported instances of program. The 200,000-250,000 figure mesothelioma among shipyard workers. characterized the total number in the What was worrisome was that the men yards at one time; however, there was were not "asbestos workers" but rather,- much turnover, and the total number of individuals employed in other trades. At different individuals was much larger. the Devonport shipyard of the Royal There are no accurate data readily avail Navy, for example, mesothelioma in a able which could tell us how many differ- boilermaker, a fitter, a shipwright, a weld ent people--.carpenters, riggers;-; electri er and a laborer were described. cians, draftsmen, welders, etc.--were so This raised the important question of employed. Nevertheless, the early obser whether asbestos use in shipyards might; vations (soon augmented by later stud result in the exposure of the workers em- . ies7-*) pointed to a potentially serious ployed in many trades, to dust derived problem. from the few "asbestos workers" in their ; Harries has recently published his fur midst. In 1943; in the United States, for ther observations at Devonport, through example, approximately one in 500 ship 1973.'By the end of the year, he had ob yard workers was ap insulator. The other served 55 cases of mesothelioma in that 499 included welders, shipfltters, machin shipyard alone. Again, trades other than ists, pipefitters, electricians, boilermakers "asbestos workers" gave evidence, of the and painters (Thble 6). The significance of hazard. Only two of the 55 worked directly this question is made apparent by the fact /with asbestos flagger, sprayer). The other that during World War II, approximately 53 included 14 shipwrights, nine boiler 4,500,000 men and women worked in our makers, eight fitters and eight electricians shipyards, many Of them under conditions (Tfcble 7). in which exposure to asbestos was possible. - John Edge of High Carley Hospital After World War'll the total number of has published similar data from shipyards shipyard workers rapidly decreased from in Barrow (Table 8)10; his most recent a high of 1,700,000 in the last months of observations are particularly disturbing.11 1943 to 200,000 or so; During the period In Barrow, 429 individuals were seen, be- VOL 28. NO. 2 MARCH/APRIL 1978 00l -7919