Original article

Scand J Work Environ Health 1982;8 suppl 1:43-47    pdf

Analysis of a follow-up study: an example from asbestos-exposed insulation workers.

by Campbell MJ, Langlands JH

An 11-a follow-up study was carried out on a working population of asbestos insulation workers to investigate the possible progression of symptoms and signs. A total of 166 men had repeat radiology, and the 43 men who had progressed in radiography category of profusion of small irregular opacities (as determined by the ILO U/C International Classification of Radiographs of Pneumoconioses, 1980) comprised 37 (32%) of the 117 smokers, 3 (17%) of the 18 exsmokers, and 3 (10%) of the 31 nonsmokers. For 148 men over 20 a of age at the time of original study, and with lung function measured in both surveys, smoking was associated with a significantly reduced transfer factor (TLCO). For smokers in category 0 at first survey, a low TLCO was associated with subsequent progression to higher radiographic categories.