Fig. 4

For the lead-exposed group, subgrouping analysis was performed on the basis of the geographic latitude of the population’s residence. (a) High lead exposure. (b) Moderate lead exposure. CI: confidence interval, DL: DerSimonian‒Laird.

For the lead-exposed group, subgrouping analysis was performed on the basis of the geographic latitude of the population’s residence. (a) High lead exposure. (b) Moderate lead exposure. CI: confidence interval, DL: DerSimonian‒Laird.