Assessment of Pulmonary Function in Young and Elderly Shift Workers of a Steel Plant

The present investigation was undertaken to examine the effects of shift work on pulmonary function. 217 subjects from a local steel plant, volunteered for this study. Of these, 65 were day workers (DWs) and 152 were shift workers (SWs). Pulmonary function, such as vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), peak expiratory flow rate (PEFR) and percent deviation of PEFR from the expected PEFR in each subject was measured between 09:00 to 11:00. Both day workers (DWs) and shift workers (SWs) were divided into two groups, based on age, i.e., ≤ 40 y and ≥ 41 y. The results indicate that the average levels of VC, FVC, FEV₁ and PEFR were significantly lower in older age in both DWs and SWs when compared to their younger counterparts. Although elderly shift workers had higher levels of VC, FVC and FEV₁ than day workers of comparable age, the difference was not statistically significant for FVC and FEV₁. In contrast, average value of PEFR was lower in older shift workers. Further, mean percent deviation of observed PEFR from the expected value was conspicuously low in elderly shift workers. In summary, shift work appears to accelerate age-related decline in PEFR at least in elderly shift workers. Results of multiple regression analysis and correlation analysis compliment this finding.