Clinical Uses of 2,3—dimercaptopropanol (Bal). Ii. The Effect of Bal on the Excretion of Arsenic in Normal Subjects and After Minimal Exposure to Arsenical Smoke

It has been shown by several investigators (1, 2) that "BAL " (2,3-dimercaptopropanol) accel-erates the excretion of arsenic in experimental animals poisoned with various arsenicals. In man also, the cutaneous application of BAL ointment (3) or the intramuscular injection of a solution in peanut oil and benzyl benzoate (4, 5) in cases of arsenical dermatitis sometimes results in an increased urinary arsenic excretion, as de-termined by analyses on 12- to 24-hour specimens collected before and after its administration. In view of the short-lived effect of BAL in experi-mental animals, it is possible that these effects of BAL on urinary arsenic excretion in man would have been more prQnounced and more regular had it been possible to obtain urine specimens at 2- to 4-hour intervals. The present paper represents an attempt to determine the effect of BAL on the normal uri-nary arsenic excretion in man, as compared with its effect in human subjects exposed for brief intervals to minimal concentrations of an arseni-cal smoke (diphenylcyanoarsine). By treating the latter group at varying intervals after exposure and by obtaining urine specimens at 2-hour in-tervals, it was hoped to delimit somewhat more precisely its effect on the urinary excretion of arsenic, and to ascertain whether BAL could be used to confirm suspected minimal exposure to arsenical poison gases. The results might be of significance also in relation to the detection and prevention of industrial arsenic poisoning.