Gender related differences of low level exposure to occupational irritants--a three-year follow-up of chemical industry workers.

ABSTRACT

The authors followed changes in the ventilatory function in a group of 102 chemical workers over a three year period to evaluate gender related differences on respiratory effects of low concentrations of occupational irritants. Measurements were performed annually and the results of ventilatory test were compared to predicted normal values. Lung function was measured by recording maximum expiratory flow-volume (MEFV) curves. Baseline data show ventilatory function impairments of the obstructive-restrictive type, as measured by the Tiffeneau index and FEV1. After one and two years of exposure, impairment in flow rates at low lung volumes became prominent. Analysis of lung function in three years of the study suggests obstructive impairments mostly in the larger airways accompanied by a restrictive component. The ventilatory flow at low lung volumes was characterized by obstruction, but not by restrictive findings. Women appear to be more sensitive than men to the irritant effects of these exposures as measured by flow rates at low lung volumes--the smaller airways (FEF50% = 82.7 +/- 23.6 in women and FEF50% = 92.1 +/- 32.1 in men; p = 0.017), while men experienced greater changes than women to irritant effects on their ventilatory capacity--the large airways (FVC = 99.6 +/- 10.6 in men and FVC = 106.74 +/- 9.8 in women; p = 0.001). The additive effect of smoking to environmental irritation is demonstrated by the proportionately lower lung capacity in smokers. Overall, the effect of these pollutants in women is more synergistic than additive.