Decades after the industrialized world largely eliminated lead poisoning in children, the potent neurotoxin still lurks in one in three children globally. A new study in Bangladesh by researchers at Stanford University and other institutions finds that a relatively affordable remediation process can almost entirely remove lead left behind by unregulated battery recycling—an industry responsible for much of the lead soil contamination in poor and middle-income countries—and raises troubling questions about how to effectively eliminate the poison from children’s bodies.