Longitudinal and cross-sectional analyses of lung function in steelworkers.

Abstract

We evaluated associations between dust exposure, demographic factors, and lung function by longitudinal and cross-sectional analyses in 475 steelworkers who participated in at least three spirometry tests over 5 yr between 1982 and 1991. Baseline and follow-up spirometry and changes between baseline and final follow-up assessment attributable to age, height, weight, weight gain, smoking status, pack-years, and years worked in dusty areas were examined using stepwise multiple linear regression techniques. Smoking, aging, being overweight, excessive weight gain, and dust exposure were related to a lower level and a steeper slope of decline of pulmonary function. Cigarette smoking was also an important risk factor. Dust exposure was related to the level of lung function, with a stronger effect at baseline than at follow-up. Estimated loss at baseline of FEV1, FVC, and FEV1/FVC% was 9.3, 6.4 ml, and 0.1 % per year of employment in a dusty area, respectively, whereas the association between dust exposure and longitudinal decline of lung function was weak. However, a strong relationship between weight gain and longitudinal decline of FEV1 and FVC was found. Estimated decreases in FEV1 and FVC attributable to weight gain were 4.7 and 6.3 ml per lb/yr, respectively. This work suggests that weight gain is an important determinant for longitudinal lung function decline. This large impact of weight gain in the decline of lung function in a middle-age and relatively overweight working population has not been previously reported. Additional work needs to be undertaken to show the strength of this relationship in other populations.

Relationship between Chest X-ray Findings and Pulmonary Function Tests in Dust Workers

“…There are a large number of reports on the effect of smoking in reducing pulmonary function in pneumoconiosis 22,25,29,[31][32][33][34][35][36][37] . In this study, smoking habit was not analyzed, since a survey on smoking was not included in the pneumoconiosis health examination.…”

Fifteen Year Follow-Up Study of VC and FEV1 in Dust-Exposed Workers.

“…The present longitudinal study selected smoking as a predictor of VC and FEV 1 , which decreased 6.1 and 5.8 ml/y, respectively. Several previous longitudinal studies reported that smoking was strongly related to a decline in lung functions not only in subjects with pneumoconiosis 7,15,17,18,22,24,25) , but also in a healthy population 32) . The study by Soutar and Hurley 18) of British coal miners reported that according to the statistical model at age 60 and zero dust exposure, mean FEV 1 in ex-smokers and current smokers was 212 ml and 327 ml lower than that of never-smokers, respectively.…”

“…However, many of the Japanese studies were cross-sectional [2][3][4][5] and only a small number were longitudinal [6][7][8] . In other countries, several longitudinal studies focused on individual occupational categories [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] although studies across categories through a study area were rare 28) . The present study focused on workers exposed to one or more of 17 types of dust categories listed in the Enforcement Ordinance of Pneumoconiosis Law 29) .…”

Respirable Dust Exposure and Respiratory Health in Male Taiwanese Steelworkers

“…However, Pham et al detected a significant deterioration of FEV 1.0 and FEV 1.0 %FVC in steelworkers compared with a reference group of unexposed workers in a five-year longitudinal study 2) . Wang et al found significant loss of FEV 1.0 , FVC, and FEV 1.0 %FVC at the cross-sectional baseline data, whereas the association between dust exposure and longitudinal decline of lung function was weak 4) . Nemery et al also showed that the more pronounced decrease in FEV 1.0 and FEV 1.0 %FVC found over the night shift of strandcasting workers in an over 21 d shiftwork 3) .…”

“…Hazardous dust is one of the most important exposures in steelworkers. There are only a few published studies on the respiratory health of steelworkers and these have showed that chronic bronchitis and decreased lung function values [1][2][3][4][5] are associated with atmospheric pollution, especially in the coke oven plant [6][7][8][9] . However, all of them lacked an appropriate assessment of dust exposure, especially the respirable fraction, leaving the question of association between actual amount and respiratory impairment still unanswered.…”