Reuben A, Elliott ML, Abraham WC, et al. - In this longitudinal prospective cohort study with a median 34-year follow-up, experts explored whether childhood lead exposure is correlated with MRI measurements of lower structural integrity of the brain in midlife. Of 1,037 original candidates, 997 were alive at age 45 years, of whom 564 (57%) received lead testing at age 11 years (302 [54%] male) (median follow-up, 34 [interquartile range, 33.7-34.7] years). At age 11 years, mean blood lead level was 10.99 (SD, 4.63) μg/dL. No statistically significant link was found between childhood blood lead levels and self-reported cognitive problems. Differences in MRI measurements of brain structure that indicated lower structural brain integrity in midlife, including smaller cortical surface area, smaller hippocampal volume, lower global fractional anisotropy, and an older estimated brain age, were correlated with higher childhood blood lead levels. Some results can reflect type I error because of the large number of statistical comparisons.