Health Risk Appraisal by Ventilatory Capacity

Abstract

Ventilatory evaluation has been widely used to investigate occupational effects on the respiratory system. This paper reports on a cross-sectional epidemiological study in Singapore carried out on four different occupational groups. A total of 999 male workers were evaluated by a spirometer interphased with a microcomputer. Forced Expiratory Volume in one second (FEV₁) and Forced Vital Capacity (FVC) of each worker were measured. The results suggested that ventilatory capacities are significantly correlated to age and height. Smokers, however, did not differ significantly from non-smokers in their FEV₁ and FVC values. This was probably due to the fact that they were relatively light smokers. After adjustment for age and height, the Chinese were found to have slightly higher ventilatory capacities than the Malays in both the FEV₁ and FVC. One important observation from the present study was that occupation was found to have a significant influence on lung capacity. Aircraft mechanics and firemen were found to have a higher mean FEV₁ than other occupational groups-probably due to the stringent recruiting criteria of these two groups of workers. However, firemen also tended to have a greater reduction in lung volumes with increasing age. The rates of decrease in FEV₁ for firemen, blue collar telecommunications workers, aircraft mechanics and sedentary workers were 0.031, 0.029, 0.026 and 0.016 litres/year, respectively. The rate of decrease in FVC showed a similar pattern of 0.022, 0.019, 0.011 and 0.006 litres/year, respectively. This finding indicates that sedentary workers appear to have a lower respiratory health risk compared with their counterparts in other sectors. In contrast, firemen are constantly facing possible respiratory hazards. As demonstrated here, measurement of ventilatory function could be a useful predictor for surveillance of respiratory hazards. However, certain factors like age, height, ethnic origin and smoking habits must be considered in the analysis and interpretation of results.