SODIUM 2,3-DIMERCAPTOPROPANE-1-SULFONATE CHALLENGE TEST FOR MERCURY IN HUMANS .3. URINARY MERCURY AFTER EXPOSURE TO MERCUROUS CHLORIDE

The sodium salt of 2,3-dimercaptopropane-1-sulfonic acid (Di-maval; DM PS) challenge test has been given previously to humans exposed to elem ental mercury (vapor) or mercuric salts, but not mercurous salts. The test (300 mg p.o., after an 11-hr fast) was given to 11 factory worker s who make a skin lotion that contains mercurous chloride, eight users of the skin lotion and nine controls. Urines were analyzed for total mercury by using cold vapor atomic absorption spectrophotometry. The m ercury excreted for 6 hr before and 6 hr after DMPS treatment was 113 mu g +/- 26 and 5037 mu g +/- 682 S.E.M. for the skin lotion makers; 1 6.2 mu g +/- 3.4 and 1410 mu g +/- 346 S.E.M. for the skin lotion user s; and 0.49 mu g +/- 0.11 and 18.4 mu g +/- 7.1 S.E.M. for the control s, respectively. The increases in urinary mercury resulting from the D MPS challenge test were 45-, 87- and 38-fold, respectively. The result s demonstrate that, in humans exposed to mercurous chloride, DMPS incr eases the urinary excretion of mercury and that the DMPS/mercury chall enge test is of value for a more realistic estimation of mobilizable m ercury. An attempt to associate genotoxicity, as indicated by micronuc lei content in buccal cells, with mercury exposure was inconclusive, p erhaps because of the small number of subjects.