Rare cases of severe life-threatening lead poisoning due to accident or chronic occupational exposure to lead and manganese: Diagnosis, treatment, and prognosis.

Background: Chronic long-term, low-dose environmental and occupational exposure to lead (Pb) has been extensively studied in large cohorts worldwide among general populations, miners, smelters, or battery workers. However, studies on severe life-threatening Pb poisoning due to accidental or chronic occupational exposure to Pb and manganese (Mn) were rarely reported.

Methods: We present one case of acute severe Pb poisoning and compare it with another severe chronic occupational exposure case involving Pb and Mn. A 27-year-old woman mistakenly took a large quantity of pure Pb powder as an herbal remedy; she developed abdominal colic, severe nausea, vomiting, fatigue, and cutaneous and sclera icterus. Laboratory tests showed her blood lead level (BLL) of 173.5 µg dL and urinary lead level (ULL) of 1240 µg dL. The patient was diagnosed with acute Pb poisoning and acute liver failure. In another chronic exposure case, a 56-year-old man worked in a Pb and Mn smelting factory for 15 years. He was brought to the emergency room with severe nausea, vomiting, and paroxysmal abdominal colic, which was intolerable during the onset of pain. His BLL was 64.8 µg dL and ULL was 38 µg dL, but his blood and urinary Mn levels were normal. The patient was diagnosed with chronic Pb poisoning. Both patients received chelation therapy with calcium disodium ethylene-diamine-tetraacetate (CaNaEDTA). The woman with acute severe Pb intoxication recovered well and was discharged from the hospital after treatment, and the man who survived severe Pb poisoning was diagnosed with lung cancer.

Conclusion: Clinical manifestations of acute and chronic severe Pb poisoning are different. Chelation therapy with CaNaEDTA is proven to be an effective life-saving therapy in both cases by reducing BLL. Occupational exposure to both Pb and Mn does not appear to increase Mn neurotoxicity; however, the probability that co-exposure to Mn may increase Pb toxicity in the same patient cannot be excluded.