The association among metals and changes in their concentrations in the treatment of lead poisoning in lead-exposed workers.

BACKGROUND

High-throughput metallomics studies on lead-exposed workers are rare, and the effects of lead exposure on other metals, as well as the loss of trace metals during such treatments, remain unclear.

METHODS

We recruited 1091 lead-exposed and 75 lead-poisoned workers undergoing calcium disodium ethylenediaminetetraacetate (CaNa2EDTA) treatment. Urine samples were analyzed for 33 metals/metalloids using inductively coupled plasma mass spectrometry (ICP-MS). In lead-poisoned workers, first morning urine was collected daily over a 15-day two-course of lead elimination treatment, plasma metals were also measured pre- and post-treatment.

RESULTS

In the high-lead group, urinary concentrations of 22 elements-including Fe, Zn, Mg, Ca, Cd, U, and Cu-were significantly higher than in the low-lead group. During the two CaNa2EDTA treatment cycles, urinary concentrations of Zn, Fe, and Cd showed trends similar to those of Pb, whereas Rb showed an opposite trend; however, Cd exhibited a one-day lag effect relative to Pb. We estimated that during lead elimination therapy, additional losses of 5.11 μg/L·kg Fe, 11.71 μg/L·kg Pb, and 62.23 μg/L·kg Zn occurred per kilogram of body weight. Furthermore, plasma iron (Fe) and lead (Pb) levels decreased by 13.30% and 61.74%, respectively, following CaNa2EDTA treatment.

CONCLUSION

Metal elements showed significant associations in lead-exposed workers, which may reflect either metabolic interactions or co-exposure in the occupational setting. Preliminary evidence suggests a potential link between CaNa2EDTA treatment and increased excretion of iron (Fe) and zinc (Zn). Given this, clinicians may wish to be alert to the possibility of monitoring these elements.