Associations between blood lead concentrations, body iron status and behavioural outcomes in children

Abstract

This study aims to investigate the association between iron deficiency and blood lead level (BLL) in a cohort of Egyptian children, and to explore their association with children’s behaviour and school achievement. This is a comparative cross-sectional study, involving 120 children (60 anemic and 60 non-anemic), aged 4–10 years, consecutively recruited from the Pediatric Hematology Outpatient Clinic. Anemia was defined as hemoglobin < 11 g/dl according to WHO criteria. Behavioural assessment was performed by Conners’ Parent Rating Scale-Revised, and blood tests for BLL, and iron indices were done. BLL was significantly higher in anemic children (4.3 ± 0.8 vs. 2.3 ± 0.6 µg/dL, p < 0.001), and children with iron deficiency (5.1 ± 1.1 vs. 2.1 ± 0.4 µg/dL, p < 0.001). Regression analysis revealed that low socioeconomic status, anemia, and low serum ferritin were independently associated with high BLL. Moreover, high BLL and low serum ferritin were independently associated with high Conners’ score. High BLL (OR1.5, 95%CI: 1.1–1.83) and high Conners’ score (OR1.2, 95%CI: 1.1–1.4) were independently associated with poor school achievement. Elevated BLL was associated with iron deficiency and behavioural dysregulation, and both were associated with poorer academic performance. Screening for iron deficiency and BLL may be considered in vulnerable children; longitudinal studies are needed to confirm the benefit. In this cohort of Egyptian children, iron deficiency and anemia were associated with higher blood lead, behavioural problems, and lower school performance. This study suggests that even modest lead exposure, especially with iron deficiency, relates to behavioural problems and poor school performance. It supports assessing both iron status and lead exposure in children with learning or behaviour concerns. It indicates a need for further studies to see whether correcting iron deficiency and reducing lead improves outcomes.