Levels of Metals in Hair in Childhood: Preliminary Associations with Neuropsychological Behaviors

For more than 100 years, an electrochemical plant has been operating in Flix (Catalonia, Spain) by the Ebro River. Its activities have originated a severe accumulation of environmental contaminants (metals, organochlorinated pesticides and radionuclides) in sediments of the Flix reservoir, while mercury (Hg) has been also frequently released to the air. Environmental exposure to industrial pollutants has been associated with decreased intelligence and behavioral problems. In the present study, we assessed, in 53 children living in the village of Flix and the surroundings, the relationships between the concentrations of a number of trace elements (As, Be, Cd, Cs, Hg, Mn, Ni, Pb, Sn, Tl, U and V) in hair and the levels of testosterone in blood, with respect to potential neuropsychological alterations. Lead (Pb) and Hg showed the highest mean concentrations in hair samples. However, the current Hg levels were lower than those previously found in children living in the same zone, while the concentration of the remaining elements was similar to those reported in the scientific literature. The outcomes of certain neuropsychological indicators showed a significant correlation with metals, such as Pb and uranium (U). More specifically, these elements were negatively correlated with working memory and hit reaction time, suggesting impulsivity. In summary, although Pb and U concentrations in hair were within standard levels, both metals could be correlated with certain, but minor, neuropsychological alterations in the childhood population of Flix. These findings should be confirmed by future birth cohort studies, with bigger study populations and using more complex statistical analyses, focused on human exposure to these specific elements