Background: Iron deficiency and lead poisoning are common co-diagnoses. Since blood lead is bound primarily to hemoglobin, treatment with iron may increase blood lead levels in lead poisoned, iron deficient subjects. Objective: To determine the effect of iron on blood lead concentration in iron deficient, lead poisoned rats. Methods: 16 male rats were fed an iron deficient diet to induce anemia. Lead was then administered 10mg/kg intravenously to ensure equal burdens. Seven days later, 8 rats were started on a control diet containing 200 PPM iron, while 8 remained iron deficient. Blood lead concentration was measured weekly using inductively coupled plasma/mass spectrometry. After 14 days of iron, the animals were sacrificed and tissue lead measured. Results: Iron treated animals had higher blood lead concentrations after treatment. (see table) As expected, hematocrits were equal prior to iron treatment (32±4% vs 33±6%;p=0.4), and were higher in the iron treated group 7 days (47±5% vs 31±3%;p<0.001) and 14 days(51±5% vs 32±4%;p<0.001) after iron. Lead concentrations in brain (0.7±0.1 vs 0.8±0.1ug/dl), kidney (33±8 vs 35±13ug/dl) and bone(71±8 vs 75±6ug/dl) were not different between groups (p=0.47,0.74,0.32 respectively. Conclusions: Although tissue lead levels remained equal, iron supplemented animals had higher blood lead concentrations than iron deficient. This study highlights the limitations of using blood lead to assess body lead burden during anemia. Given these findings, further work on intracellular lead distribution during combined iron deficiency and lead poisoning is needed to better evaluate the effects of iron status on lead toxicity.

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