Study on the Mineral and Heavy Metal Contents in the Hair of Preschool Aged Autistic Children

Abstract

The purpose of this study was to test characteristics between normal and autistic children via comparison of nutrient intakes, hair mineral, blood free radical, and serotonin contents. A total of 50 children aged 3-9 were divided into two main groups of normal control children (n=22) and autistic children (n=28) tested by child psychiatrist. The nutrient intakes by 24-hour recall method were no significantly different between the two groups. The concentrations of toxic mineral, such as cadmium (Cd) and lead (Pb) in hair of autistic children were significantly higher, while concentration of antioxidant mineral (Cu, Zn, Fe) was lower than that of normal children. The autistic children had significantly higher concentrations of blood free radical than that of normal children. No significant difference was observed in serotonin concentration between the two groups. Our results suggest a possible role of increased toxic mineral and free radical, both of which may be relevant to the pathophysiology of autism in children with developmental delay.

Does Lead Have a Connection to Autism? A Systematic Review and Meta-Analysis

“…The characteristics of the studies included in the meta-analysis are shown in Table 1 . The meta-analysis of Pb levels in hair included 17 studies [ 19 , 32 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], 13 studies in whole blood [ 20 , 31 , 34 , 44 , 58 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ], and 8 studies in urine [ 24 , 34 , 36 , 58 , 70 , 71 , 72 , 73 , 74 ].…”

“…Regarding Pb levels in hair, four studies were conducted in Europe [ 32 , 49 , 53 , 58 ], two studies in North America [ 54 , 60 ], eight studies in Asia [ 19 , 47 , 48 , 51 , 55 , 56 , 59 , 61 ], and three studies in Africa [ 50 , 52 , 57 ]. Regarding Pb levels in whole blood, two studies were carried out in Europe [ 58 , 62 ], two studies in North America [ 34 , 64 ], one study in Central America [ 65 ], five studies in Asia [ 31 , 44 , 63 , 68 , 69 ], and three studies in Africa [ 20 , 66 , 67 ].…”

“…Most studies reported higher levels of Pb in the hair of case children than in controls, in Saudi Arabia [ 47 , 73 ], Oman [ 48 ], Iraq [ 19 ], Italy [ 49 , 58 ], Poland [ 32 ], Egypt [ 50 , 57 ], China [ 51 ], the USA [ 54 ], Kuwait [ 55 ], India [ 56 ], and Jordan [ 61 ]. Other studies reported lower levels of Pb in the hair of cases than in controls, including in Morocco [ 52 ], Russia [ 53 ], Korea [ 59 ], and the USA [ 60 ]. Details of the participants, analytical techniques used, and hair Pb level values are given in Table 1 .…”