[Control studies on retired lead workers]

Nine lead-workers, with an exposure time of 26 years, are investigated 10 years, after they had retired. There are no differences in the blood-count, hemoglobin, blood-lead level, urin-delta-aminolevulinic-acid, urincoproporphyrin and delta-aminolevulinic-acid-dehydratase-activity in their blood, upon comparison with a control group without lead-exposure. The mean urinary excretion of lead (0.119 mumol/g Kreatinin = 24 microgram/g Kr.) was 8 times higher than of reached by the controls (0.014 mumol/g Kr. = 2.7 microgram/g Kr.). The injection of CaNa2-EDTA increased the lead excretion to 0.197 mumol/g Kr. = 40.8 microgram/g Kr., in the control group 0.123 mumol/g Kr. - 25.7 microgram/g Kr. (62%). Therefore these two investigations are recommended for detection of previous lead exposure.