[Excretion of hydroxyproline in the urine of workers engaged in the production of iron-manganese alloys].

Statistically significant increase of the excretion of hydroxyproline with urine has been found to occur in workers employed in iron-manganese alloy manufacture, compared with the excretion of hydroxyproline in urine of the control group. Besides, the workers employed for 10 years and longer were characterized by statistically significantly increased excretion of hydroxyproline with urine as compared to the workers employed for shorter periods. No significant differences in excretion of hydroxyproline with urine, however, were detected among workers with chronic bronchitis and among those with smoking factor less than or equal to 10 and smoking factor greater than 10. (Smoking factor = number of packages of cigarettes smoked per day times years of smoking).