Influence of long-term occupational exposure to cadmium on lung function tests results.

OBJECTIVES The study aimed at assessing the lung function in workers exposed to cadmium (Cd). MATERIALS AND METHODS Pulmonary ventilatory function was assessed in 79 workers (mean age, 50.4+/-8.9 years, 44% of male workers) previously exposed to cadmium in a cadmium battery plant. The group, not occupationally exposed to cadmium (n = 159, mean age, 48.4+/-4.2 years, 56% of males) was selected from the inhabitants of the same town. All the subjects were examined at the same out-patient-clinic. In cadmium battery workers measurements of blood cadmium concentrations have been performed since 1983 by the Nofer Institute of Occupational Medicine in Lódź, Poland. The data on cadmium concentrations in the air were obtained from the plant's files covering the period of 1981-1999. All subjects were divided into four groups according to their cumulative cadmium exposure indexes: Cd-B x t (Cd in blood in microg/l x years of exposure ) ( index 1) or Cd-A x t (Cd in air mg/m3 years of exposure) (index 2). The ranges of Cd-B x t amounted to <25; 25-500; >500-1000 and > 1000 and Cd-A x t to <0.01; 0.01-1.5; >1.5-4.0 and >4.0. Statistical analysis of the results was performed by means of one-way analysis of variance with multiple comparison tests and Fisher's exact test. RESULTS The analysis of index 1 showed that only the group with the highest exposure level (>1000 microg Cd-B x years ) had a significantly decreased values for forced expiratory volume in one second (FEV1) peak expiratory flow rate (PEF) maximum midexpiratory flow (MEF) at 25%, 50%, and 75% compared to the group with the lowest exposure (<25 microg/l x years). As revealed by the analysis of index 2, the highest exposure group (>4 mg Cd-A x t) showed a significantly decreased MEF at 50% and not quite significantly decreased FEV1. CONCLUSIONS Exposure to high cadmium concentrations in the cadmium battery plant resulted in the deterioration of some lung functions in the workers, suggesting a mild airway obstruction.