Hair toxic and essential trace elements in children with autism spectrum disorder

Abstract

The objective of the study was to investigate hair trace elements content in children suffering from autism spectrum disorder (ASD). A total of 74 ASD children and 74 sex- and age-matched controls divided into two age groups (2-4 and 5-9 years) were investigated. Hair trace elements content was assessed using inductively coupled plasma mass spectrometry. A general cohort of ASD children was characterized by 29 %, 41 %, and 24 % lower hair levels of chromium (Cr), iodine (I), and vanadium (V), respectively, whereas the level of selenium (Se) exceeded the respective control values by 31 %. In ASD children aged 2-4 years hair Cr, I and V content was 68 %, 36 % and 41 % lower than in the controls. Older ASD children were characterized by 45 % increase in hair Se levels. In a general cohort of ASD children hair beryllium (Be) and tin (Sn) levels were 50 % and 34 % lower than the control values. In the first age group (2-4 years) of ASD children 34 %, 42 %, and 73 % lower levels of arsenic (As), boron (B), and Be were detected. In the second age group of ASD children only a nearly significant 25 % decrease in hair lead (Pb) was detected. Surprisingly, no significant group difference in hair mercury (Hg), zinc (Zn), and copper (Cu) content was detected. Generally, the results of the present study demonstrate that children with ASD are characterized by lower values in hair of not only essential but also toxic trace elements.

Lead among children with autism in Iraq. Is it a potential factor?

“…Despite the genetic contribution to autism etiology, suggested by finding many genes with variable expression in ASD [7,8], evidence have shown participation of environmental factors, such as lead exposure, in the etiology of autism which agreed with our study results [12,13]. However, some studies could not observe the same finding regarding lead exposure and autism [29]. Environmental factors might influence autism by causing oxidative stress (free radicals) and impairment of methylation in autistic children and that may be due to the effect of toxic metals on sulfur metabolism [30].…”

Analysis of lead, arsenic and calcium content in the hair of children with autism spectrum disorder

“…There is increasing evidence that children with ASD have a considerable disability to process and eliminate toxins from the body [1,5,6,14,43]. Toxin accumulation leads to increased activity of free radicals in the body, which in turn affects the structure of the nervous system.…”

“…Similar effects can be observed in the case of As. Arsenic exposure significantly affects brain morphology, resulting in gliosis, neuronal degeneration, a decrease in cognitive abilities, attention, comprehension, language skills, and reduces intelligence quotient (IQ) scores [1,5,6,[11][12][13][14]. The high levels of heavy metal antagonists (e.g.…”

“…Over the last decades, numerous studies have reported a relationship between ASD and Pb and As exposure [5,[11][12][13][16][17][18][19][20][21][22][23][24]. However, there are also some reports that conclude that heavy metals exposure is not a risk factor for ASD [6,14,[25][26][27][28][29]. Therefore, an accurate evaluation of the relationship between ASD and heavy metals needs more specific research.…”

Arsenic Toxicity: Molecular Targets and Therapeutic Agents

“…Some research suggests that exposure to environmental As might be a risk factor in children for the development of autism spectrum disorder. However, these findings are inconclusive [48,49]. In experimental studies exposure to As disturbs the neurotransmitter metabolism.…”