Cross-sectional study of pulmonary function in cadmium alloy workers

Two groups of cadmium workers (7 and 9 men) and a group of reference workers (122 men) were studied for the purpose of determining the pulmonary effects of cadmium. Indices of pulmonary function, based on the forced expiratory flow volume curve and respiratory impedance, were measured for all the groups, and indicators of cadmium exposure and effects on renal tubular reabsorption functions were also measured in the two groups of cadmium workers. The mean blood and urinary levels of cadmium were 2.08 μg/100 ml (185.06 nmol/l) and 32.6 μg/l (290.04 nmol/l), respectively, and the level of inhalation exposure was estimated at about 1 mg/m³ as the 8-h average concentration for about 5 a (a measure of the duration of exposure) in the high-exposure group. The percentage of the predicted function values of the highly-exposed workers showed significant deterioration for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1.0)), peak expiratory flow, maximum expiratory flow at 75, 50, and 25% of the FVC, percentage of FEV(1.0) to FVC, and respiratory impedance, whereas those of the slightly-exposed workers were reduced only for FVC and FEV(1.0). A paired comparison between the highly-exposed workers and matched referents disclosed the same results. It was concluded that chronic obstructive pulmonary changes had been induced by cadmium in Japanese workers without a history of acute or subacute cadmium pneumonitis.