LUNG-FUNCTION IN LANCASHIRE COTTON AND MAN-MADE FIBER SPINNING MILL OPERATIVES

Objectives-This survey was conducted to investigate current lung funct ion levels in operatives working with cotton and man made fibres. Dust concentrations, smoking history, and occupational details were record ed so that factors influencing lung function could be identified. Meth ods-A cross sectional study of respiratory symptoms and lung function was made in 1057 textile spinning operatives of white caucasian extrac tion. This represented 96.9% of the total available working population to be studied. Most (713) worked currently with cotton. The remainder worked with man made fibre. Lung function was assessed by measuring f orced expiratory volume in one second (FEV(1)) and forced vital capaci ty (FVC). Exposure to cotton dust was measured in the work area and pe rsonal breathing zones, and retrospective exposure to cotton dust over a working life was estimated with accurate work history and best avai lable hygiene data. Results-3.5% of all operatives had byssinosis, 55 (5.3%) chronic bronchitis, 36 (3.5%) work related persistent cough, 55 (5.3%) non-byssinotic work related chest tightness, and 56 (5.3%) wor k related wheeze. A total. of 212 static work area dust samples (range 0.04-3.23 mg/m(3)) and 213 personal breathing zone samples (range 0.1 4-24.95 mg/m(3)) were collected. Percentage of predicted FEV(1) was re duced in current smokers (mean 89.5, 95% confidence interval (95% CI) 88-91) in comparison with non-smokers (93.1, 90.5-94.1) and FVC was re duced in operatives currently working with man made fibre (95.3, 93.8- 96.9) in comparison with cotton (97.8, 95.6-99.0). Regression analysis identified smoking (P<0.01), increasing age (P<0.01), increasing time worked in the waste room (P<0.01), and male sex (P<0.05) as being ass ociated with a lower FEV(1) and FVC. Current and retrospective cotton dust exposures did not appear as predictor variables in the regression analysis although in a univariate analysis, FEV(1) was reduced in tho se operatives exposed to high dust concentrations assessed by personal and work area sampling. Discussion-This study has documented loss of lung function in association with exposure to cotton dust. Those opera tives with work related symptoms had significantly lower FEV(1) and FV C than asymptomatic workers. Although lung function seemed to be affec ted by high dust exposures when operatives were stratified into high a nd low exposure groups, regression analysis did not identify current d ust concentrations as an independent factor influencing loss. Smoking habit was found to explain most of the measured change in FEV(1) and F VC. It is likely that smoking and dust exposure interact to cause loss of lung function in cotton textile workers.