Imported occupational lead poisoning: report of four cases

In most industrialized countries, occupational lead poisoning has become increasingly rare, however this metal remains a serious health hazard in the rest of the world. We observed four male patients (aged 35 ÷ 54 years) who had suffered recurrent abdominal pain due to recent lead exposure (for 7 to 13 months) in two Chinese battery recycling plants. On return to Italy, three of them presented normocytic, normochromic anaemia. The diagnosis was confirmed by high lead levels in the blood and urine, decreased erythrocyte δ-aminolevulinic acid dehydratase (ALA-D), raised erythrocyte zinc protoporphyrin (ZP), and elevated urinary excretion of δ-aminolevulinic acid (ALA-U) and porphyrins. Chelation with EDTA resulted in increased urinary lead excretion, improvement of the clinical picture, decreased ZP, and progressive normalization of the other lead biomarkers (Pb-B, ALA-D, ALA-U, urinary porphyrins). In conclusion, temporary work in developing countries may result in imported lead poisoning. Differential diagnosis of this unusual condition requires careful history collection and specific toxicological analysis. Preventive measures for workers going abroad are needed.