Socio-Emotional, Behavior and Cognitive Disorders Associated with Exposure to Trace Metals: A Cross-Sectional Pilot Study in School-Age Children in Haut-Katanga Province

Abstract

<b>Introduction</b>: Trace metals can negatively impact biological functions and brain development. Cognitive and neurobehavioral disorders in children are poorly documented in Haut-Katanga Province, an area with significant and multiple exposures to trace metals that can lead to the exacerbation of cognitive and behavioral disorders. <b>Objective</b>: This study aimed to characterize the behavior of schoolchildren linked to their cognitive performance in urban and rural environments. <b>Methods</b>: A cross-sectional pilot study was conducted on 52 schoolchildren aged 6 to 11 (22 from rural areas presumed less exposed to metals and 30 from Lubumbashi, DRC). This study employed NEPSY-II tests, the Strengths and Difficulties Questionnaire (SDQ-Tutor), ENA 2020 software and trace metal spectrometry assays. Statistical tests were carried out with SPSS-20 and Stata-18. <b>Results</b>: Our findings revealed a correlation between children's malnutrition and low mother's education. The "total difficulties score" was more prevalent in rural areas (73%) compared to urban settings (37%) <i>p</i> < 0.05), in contrast to the "negative impact of difficulties" (59% versus 57%, <i>p</i> > 0.05). Urban children demonstrated superior cognitive performance, particularly in "facial affect recognition" (8 versus 4, <i>p</i> = 0.013) and "inhibitory control" (6.5 versus 3, <i>p</i> = 0.032). As-U(urine), Cd-B(blood), Hg-B, Mo-U, Ni-U, Pb-U, Pb-B and Sb-U were elevated compared to references. In general, urban areas had higher metal levels than rural areas. Blood and urine metals showed a complex and significant relationship with behavioral difficulties or cognitive performance. <b>Conclusions</b>: The observed behavioral issues, cognitive performance deficits and their association with nutritional deficiencies and trace metal exposure suggest a multifactorial neurodevelopmental origin. These findings highlight the need for further research in the region.