Heavy metals and trace elements in scalp hair samples of children with severe autism spectrum disorder: A case-control study on Jordanian children

Abstract

BackgroundElemental analysis has been increasingly used for biomonitoring heavy metals and trace elements. MethodsThis study monitored the levels of two heavy metals (Al and Pb), and seven trace elements (Macroelements Mg, K, P and Ca; Microelements Zn, Cu, Fe) in scalp hair of 57 children with severe autism spectrum disorder (ASD) and 50 age-matched controls, using Inductively Coupled Plasma Atomic Emission Spectrophotometry (ICP-AES). ResultsCompared to controls, significantly higher levels of Al (p = 0.001), Pb (p = 0.001) and K (p = 0.021), with lower levels of Mg and Zn (p = 0.038) were observed for the ASD group. ASD boys had higher levels of Al (p = 0.001), Pb (p = 0.001) and K (p = 0.017) than control boys, while ASD girls had higher Pb levels (p = 0.005) than control girls. The ASD subgroup exposed to passive smokers had higher levels of Al (p = 0.033) and Pb (p = 0.001, and the ASD subgroup not exposed to passive smoke had higher levels of Al (p = 0.011), Pb (p = 0.001), K (p = 0.003); and lower levels of Mg (p = 0.011) than their controls. Other confounding factors and the correlation between these elements were also investigated. ConclusionThis data suggests that exposure to Al and Pb, increase intake of K, and decreased intake of magnesium and zinc, may contribute to ASD etiology.