Blood Lead Levels and Their Association with Iron Deficiency and Anemia in Children

Lead is a ubiquitous and neurotoxic heavy metal particularly harmful to children, who are more susceptible than adults to its toxic effects. The prevalence of lead poisoning and iron deficiency (ID) is high in socioeconomically vulnerable child populations, negatively affecting neurocognitive development in children. Although numerous studies have shown the association between blood lead levels (BLL) and ID, the issue remains controversial. Here, we aimed to identify the association between BLL and iron nutritional status in children. We conducted an analytical cross-sectional study of healthy children aged 1-6 y attending periodic health checks in primary healthcare units from La Plata and its surroundings, Buenos Aires, Argentina, between 2012 and 2017. We performed anthropometric evaluations and determined BLL, hemoglobin (Hb) and serum ferritin levels. Blood lead levels ≥ 5 µg/dL were defined as elevated BLL; ferritin levels < 12 ng/ml were considered ID; Hb levels < 11 g/dL (< 11.5 g/dL for children ≥ 5 y) were defined as anemia. Data were analysed using Mann Whitney test, Student´s t-test, chi-square test and logistic regression. The R package (v. 4.2.2.) was used for the statistical analysis of data. The sample included 392 children (mean age, 2.4 ± 1.4 y; 44.6% females). The prevalence of elevated BLL, ID and anemia was 8.7%, 26.3% and 31.8%, respectively. We found a significant association between elevated BLL and ID (odds ratio [OR], 95% confidence interval [CI]: 3.16 (1.50, 6.63)). The prevalence of elevated BLL was 16.2% and 5.8% in children with and without ID, respectively (p = 0.003). We also found association between elevated BLL and anemia (OR 95% CI: 3.03 (1.49, 6.29)). In conclusion, blood lead levels ≥ 5 µg/dL were significantly associated with ID and anemia in children aged 1-6 years.