A Comparison of Two Classifications of Coal Worker's Pneumoconiosis

Abstract

To the Editor.— The Federal Coal Mine Health and Safety Act of 1969 offers all working coal miners, at no expense to themselves, the opportunity to have chest roentgenograms taken at intervals. Moreover, instructions were published in the Federal Register 1 stating that the roentgenograms should be categorized according to either the International Union Against Cancer (UICC) 2 or International Labour Organization (ILO) classifications. 3 Most persons are notaware that there are two 1968 ILO classifications of pneumoconiosis; namely, an extended and a shortened version. 3 It is frequently assumed that the two 1968 ILO classifications are similar. This is an erroneous assumption. Firstly, the shortened 1968 ILO classification, like the 1959 version, 4 includes a suspect category (Z), while the UICC and the extended ILO classifications do not. Secondly, provision is made to interpret irregular opacities in the UICC but not in the shortened version of the ILO