Which scenario indicates the need for chelation therapy for lead poisoning?

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Chelation therapy is used when the lead burden is high enough to pose a serious risk of ongoing toxicity, so treatment is started only after the level passes a defined threshold. Among the scenarios, the situation with a markedly elevated lead level crosses that threshold, making chelation appropriate to reduce body lead and prevent further neurotoxic effects. The other scenarios show lead levels that are below the treatment threshold, so chelation isn’t indicated there; management focuses on removing exposure and monitoring.

Chelation works by using agents that bind circulating lead and tissue stores, forming complexes that are excreted in urine. Because chelation can have risks, it is reserved for significant poisoning and is guided by the level of exposure along with symptoms. In practice, treatment may involve agents such as calcium disodium EDTA or other chelators, depending on severity and patient factors.