Proc 13 Int Congr Health, N.Y., 1960 (1961)

In 1947 Schwarzenbach and Ackerman discovered a new compound EDTA which belongs to the group of complexions. This drug was applied for the first time in the USA in 1952 in the therapy of lead poisoning, and the results obtained by other drugs used for that purpose. Late, this drug was applied in many countries and since then over 100 different papers, all favoring its positive effect, were made known. But the research work was limited to a small number of cases. Today CaNa₂EDTA is the choice drug in treatment of lead poisoning.

In order to examine this drug completely, it was applied to persons who work with lead. The drug (Mosatil-Bayer) was applied to several groups and in different ways. The examination included a total of 92 persons.

The fourth group (seven persons) was treated with Mosatil tablets, two tablets three times every day (0.5 g Ca₂EDTA per tablet), during seven days.

Urinary lead excretion in persons that were treated parenterally, individually as well as a whole, was higher than in ones treated with tablets.

Figure 1 demonstrates urinary lead excretion. It is evident that this excretion is higher on the first day and that the differences for various groups are remarkable.

Subgroup B, also composed of eight workers, consumed 3g of Mosatil per day in three doses – at the beginning, in the middle, and at the end of working time. Tablets were also administered in a course of eight days. All the workers remained full time at their routine jobs.

The results obtained are shown in Figures 5 and 6.

Urinary lead excretion in Subgroup A reaches the maximum on the second day of administering tablets when it occurs, the average excretion values are about seven times higher than at the beginning. The following days this value decreases constantly, and two days after completion of administering it falls almost down to the pretreatment level. In Subgroup B urinary lead excretion is also maximal on the second day, and the quantities of excreted lead are eight times higher than at the beginning of treatment. It is evident the excretion in this subgroup remains longer and on a higher level than was the case in Subgroup A.

Urinary coproporphyrin excretion in Subgroup B during the whole period of time, especially after the third day of treatment, shows a more remarkable decrease in the Subgroup A.

During treatment blood lead diminished 0.015 mg per cent in Subgroup A and 0.030 mg per cent in Subgroup B.

The number of stippled cells diminished in both subgroups.

Thus it could be concluded that every worker of the Subgroup A excreted on an average 13.3 mg of lead per liter of urine. In other words, every worker in a course of eight days excreted as much lead he would do in33.9 days under normal circumstances without administering the tablets. Every worker of Subgroup B excreted on an average 17.8 mg of lead per liter of urine; that is, in the course of eight days every worker excreted as much lead he would normally do in 51.6 days if not treated with Mosatil.

4. On a trial of prophylactic values of Ca₂EDTA tablets, administered from 1 to 3 g per day in a course of seven days, an increase of lead and decrease of coproporphyrin excretion in urine and decrease of blood lead as well as an improvement of clinical symptoms were found. Following intermission of administering Ca₂EDTA, after a certain period of time after workers resumed their routine jobs, all these symptoms returned again to the levels established before treatment. Bearing in mind that this drug, like any other one, cannot be administered permanently in unlimited quantities, it does not represent a perfectly satisfactory medicine in the prophylactic of lead poisoning.

5. Regardless of the fact that resorption of Ca₂EDTA is small by peroral administering, it is considered the drug can be applied, especially in cases where a possibility of consuming lead compounds does exist.

6. In the cases examined there were no side effects and/or toxic manifestations. Nevertheless, it is considered a thorough physical examination is necessary, especially for kidney damage; urine should be controlled during the whole period of administering CaNa₂EDTA.

7. As a diagnostic test, CaNa₂EDTA can be useful in those cases where diagnosis is not clear. If urinary lead excretion contains more that 0.34 mg per 24 hours after 3 g CaNa₂EDTA tablets (32 tablets of 0.5 g three times per day) were administered, this is a symptom of rich lead depositions in the organism.

10. Considering the individual safety appliances, as well as temporary administering of CaNa₂EDTA, do not provide complete protection of the persons working with lead, it is essential – first of all on the working places where higher concentrations of lead are developed – that general hygienic and technical protection measures are maintained during the working process.