Evaluation of an occupational respiratory exposure to a zirconium-containing dust.

A group of handfinishers of zirconium metal reactor components questioned whether the dust to which they were exposed would cause chronic lung disease or cancer, or both. To investigate this possibility, the work environment was surveyed, and 32 male employees who had worked as handfinishers from one to seventeen years, were compared to a group of controls in reference to a respiratory questionnaire, chest x-ray findings, and expiratory lung function tests. The controls were matched to the handfinishers for age, sex, payroll status and smoking history. No significant differences were found between the exposed and the control groups. Results of earlier animal respiratory studies vary from no effect to definite pathology. Previous employee exposure studies are short-term and have methodological shortcomings. It would appear that lifetime animal respiratory studies and systematic epidemiological studies of employee populations with long-term inhalation exposure are needed to demonstrate unequivocally whether zirconium and zirconium compounds are harmful.