Biomaterial Database

Cognition in children does not suffer from very low lead exposure. 1998

B Minder, and E A Das-Smaal, and J F Orlebeke

Department of Physiological Psychology, Vrije Universiteit of Amsterdam.

We studied the relationship between exposure to lead and memory and attention in children. Participants were 313 boys aged 9 to 12 years who attended special education schools in the Netherlands. Children whose possible attentional or memory problems were obviously due to causes other than lead contamination were excluded from the study. Cognition was assessed by extensive theory- based testing. Blood lead concentration was measured to assess body lead burden. Possible confounding factors that might affect blood lead level and/or cognitive functioning were assessed. Blood lead levels were higher in children with lower socioeconomic status and in children with more hand-to-mouth behavior, and varied seasonally, with higher values in spring and summer. The mean blood lead level was 44.4 microgram lead per liter blood, which is considered low. Only 2% of the children showed a slightly higher blood lead level than the American safety standard. To obtain robust measures of cognitive aspects, we performed a factor analysis. The results showed that blood lead level did not influence any of the cognitive factors. Therefore this study, despite being designed to maximize the chance of finding an effect in asymptomatic children, does not support a relationship between lead at very low doses (below 100 micrograms/liter blood) and cognition in schoolchildren.

UI	MeSH Term	Description	Entries
D007854	Lead	A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.2, symbol Pb.
D007855	Lead Poisoning	Poisoning that results from chronic or acute ingestion, injection, inhalation, or skin absorption of LEAD or lead compounds.	Poisoning, Lead,Lead Poisonings,Poisonings, Lead
D007859	Learning Disabilities	Conditions characterized by a significant discrepancy between an individual's perceived level of intellect and their ability to acquire new language and other cognitive skills. These may result from organic or psychological conditions. Relatively common subtypes include DYSLEXIA, DYSCALCULIA, and DYSGRAPHIA.	Adolescent Learning Disabilities,Adult Learning Disabilities,Child Learning Disabilities,Developmental Academic Disability,Developmental Academic Disorder,Developmental Disabilities of Scholastic Skills,Learning Disabilities, Adolescent,Learning Disabilities, Child,Learning Disorders,Academic Disorder, Developmental,Adult Learning Disorders,Developmental Disorders of Scholastic Skills,Learning Disorders, Adult,Learning Disturbance,Scholastic Skills Development Disorders,Academic Disabilities, Developmental,Academic Disability, Developmental,Academic Disorders, Developmental,Adolescent Learning Disability,Adult Learning Disability,Adult Learning Disorder,Child Learning Disability,Developmental Academic Disabilities,Developmental Academic Disorders,Disabilities, Adolescent Learning,Disabilities, Adult Learning,Disabilities, Child Learning,Disabilities, Developmental Academic,Disabilities, Learning,Disability, Adolescent Learning,Disability, Adult Learning,Disability, Child Learning,Disability, Developmental Academic,Disability, Learning,Disorder, Learning,Disorders, Adult Learning,Disorders, Learning,Disturbance, Learning,Disturbances, Learning,Learning Disabilities, Adult,Learning Disability,Learning Disability, Adolescent,Learning Disability, Adult,Learning Disability, Child,Learning Disorder,Learning Disorder, Adult,Learning Disturbances
D008297	Male		Males
D008568	Memory	Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D003072	Cognition Disorders	Disorders characterized by disturbances in mental processes related to learning, thinking, reasoning, and judgment.	Overinclusion,Disorder, Cognition,Disorders, Cognition
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man