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

Abstract

In 12 men exposed for 6 mins. to minute concns. of an arsenical smoke, there was an immediate increase in the urinary excretion of As, which gradually fell thereafter from an initial average of 6.8 [gamma]/hr. to an avg. of 3 [gamma]/hr. 72 hrs. after exposure. The corresponding value in a group of 6 control subjects was 2 [gamma]/hr. In both groups, those exposed to As as well as the normal controls, a single intramusc. injn. of BAL at a dose of 3.5 mg./kg. administered as a 10% soln. in peanut oil and benzyl benzoate was followed by a significant and regular increase in the rate of urinary As excretion. The effect usually reached a maximum within 2-4 hrs., and was usually not demonstrable thereafter. The largest increase, both absolute and relative, was observed in the group of subjects treated with BAL soon (61/2 hrs.) after exposure to the arsenical smoke. The significance of these observations with respect to the optimum time interval between successive therapeutic injections of BAL, and its use to detect abnormal exposure to As, is discussed.