Time required for blood lead levels to decline in nonchelated children

Objective: To determine the time for a decline in blood Iran to less than 1 0 mug/ dL, in nonchelated children who are enrolled in case management. Stu dy Design: Retrospective analysis of venous blood lead data of lead-poisone d children followed in a case management program designed to decrease lead exposure, Children were excluded if their blood lead herd not yet declined to less than 10 mug/dL, if they received chelation therapy, or if they had not received follow-up for more than 15 months. We calculated the time betw een peak elevation of lead and decline to less than 10 mug/dL, Data were ca tegorized based on the child's peak blood lean and season in which their pe ak blood lead occurred. Data were analyzed using ANOVA and linear regressio n. Kaplan-Meier survival analysis was used to describe data in population f orm. Results: 579 patients were included in the analysis. Blood leads of 25 -29, 20-24, 15-19, and 10-14 mug/dL required 24.0, 20.9, 14.3, and 9.2 mont hs, respectively, to decline to less than 10 mug/dL, For continuous data, a linear relationship was described by the following equation: Time (# of mo nths required to achieve a blood lead less than 10 mug/dL) = 0.845 X peak l ead; p < 0.0001. Kaplan-Meier curves complement the findings in a populatio n-based fashion. Conclusions: The mean time for blood lead to decline was l inearly related to the peak in blood lead. The time for 50% of the blood le ad to decline to less than 10 <mu>g/dL was not linear and varied with peak lead.