Document jB82ZND0rkZRxxeKmKmr3n682

1/V -V"*- : rr\*'.a-flC1*' K . / $Mti r *jMI * S"1. : Annals New York Academy of Sciences in this study 383 of 611 employees have worked for less than five years! Only 66 of 511 had worked for more than 10 years. Seventy-three of 611 actually were employed for less than one year (page 47). Moreover, of th* er* appeared to I heavy brake iinin Medical data ii 511 studied, 76 were "controls" which consisted of 40 office workers and other employees "not exposed to asbestos dust" and 27 persons seekini More than one-hiof age (page 471 employment in the asbestos industry for the first time (page 46). It should be noted that these were not true controls since on page 42 It is learned tft of any grout that the average .- that even in these areas atmospheric dust concentrations ranged from with the post off. 120,000 to 1,200,000. We now know that the effect of the environment U potentially very important In Wagner's studies in South Africa most of the mesotheliomas occurred in association with environmental asbestos ex Ud chemical ind> that the asbestof this country. On posure and not in an industrial exposure.* Controls should have been sought 1920" (page 48). In an area in which asbestos was not present at all. Thus, the baseline eight . This whs a "r* per cent cough and seven per cent dyspnea may be at least partly significant (IlflIruHli-s it enb (page 62) and the findings with leas than 26 mllllon-partide-yesrs.of M 9*ad are buried. jp&ig^.percent cough and 12 per cent dyspnea mayhavegreater algnificanc^^^.- jeMmlnedliC^E1 itwjJSpSir it f* important to atreas'that the five mppcf value Is based uponduxt ' hrtth eauttonmec counts of ail particles, fibrous and particulate, asbestos or not. Therefore, it is particularly ti cannot be presumed to represent s safe limit of asbestos in all application!. pipage 58). The dust counts given were average. Yet the range was enormous and Finally, note r , , there is much biological evidence V indicate that peak expoauresmay be^/1 ^fi^r.Triore Important than cbnstanfhv^riQ b^gKmlrt'exposure since"on'tbwe^'f ' occasions the defense mechanisms of the lungs may be overwhelmed with huge' retention at these particular times, Pickermen are listed in table 8 t cubic foot may b dust exposu re un as being exposed to from 64.8 to 74A mppcf. However, during certain ph&sei of their operationa dust concentrations may range as high as 211 mppcf (page 26). In carding, for example, the exposure Is listed in table 9 as reached 139 mppcf.'/SlmTiaf statiatlcs'are available for other operations... Twisting frequently produced concentrations of over 20 mppcf and when ;~L American C Threshold ustrial V j^*ATBia. H ji.asbestos te '.i-l. VoawAin. A. of asbestor proportionately there were more and longer fibers.'.'Table 12 indicated f^X./counte of 4.7 mppcf, yet the dust created depended on many factors ineludyyb'sref-ing thehumberSf warp threads per unit of width, quality of material used, **svhether or not dry weaving'was used, etc. In some weaving operations, counts of more than 140 mppcf were found. Although dry and 'wet weaving gave different results (table 12), operators were interchangalilr j-cl and tlw machines were often side by side. Counts nlsu varied when nit Wni* iTroom were used nr not, sinre the room slr.e mid exhsust ventilation wen* constant. What was woven also make a difference, broke lining weav .don, Eng}i ,, Waoner. J.l *'iV?C.-*hUlon s 1 ' y.Tndust. IRQftooo I032 ' PRODUCED BY FORD