Toxic Effect of Some Metals on Language Development in A Sample of Children in Sohag Governorate

Document Type : Original Article


1 Department of Forensic Medicine & Clinical Toxicology Faculty of Medicine, Sohag University, Egypt

2 Department of Forensic Medicine & Clinical Toxicology , Faculty of Medicine, Sohag University, Egypt

3 Department of ENT- Phoniatrics Unit, Faculty of Medicine, Sohag University, Egypt


Chronic exposure to metals has subtle toxic effect on the nervous system in early childhood. It may cause impairment of language and learning development. The aim of the present study is to estimate the level of some metals (copper, lead, cadmium, manganese, and zinc) in blood samples of children having delayed language development without any obvious causes and to assess the relationship between those metals and their toxic effect on language development. The current work was conducted on 60 children having language disorder and 40 normal healthy cases taken as controls. All studied cases were subjected to full history, general examination, vocal tract examination and neurological examination. The children were assessed clinically by many tests such as; Stanford Binet test, Vineland Social Maturity Scale and Arabic language test. Evaluation of peripheral hearing was done by tympanometry and pure tone audiometry. The level of metals in the blood of the studied cases was estimated by Inductively Coupled Plasma Mass Spectrometry (ICP-MS).The diseased children showed significant retardation of language development associated with decreased IQ levels and delayed development of other body activities such as sitting, walking and talking. In addition, the level of the studied metals, especially lead was higher in the diseased children than in the normal group. The diseased cases showed a statistically significant higher lead level than the healthy cases (mean values were 22.33 ± 1.27 ∝ g/dl and 8.57 ± 1.39 ∝ g/dl respectively). It can be concluded that elevated level of blood metals in children might affect language development as well as the development of other body activities. It is recommended to measure the blood level of metals in early childhood and try to manage cases with high levels and follow up them by clinical and laboratory examination to avoid delayed language development.