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Increased blood lead levels in mentally retarded children in Greece
Insights
Elevated blood lead levels were found in children with unexplained mental retardation. This suggests lead exposure may contribute to cognitive impairment in some children.
Area of Science:
- Environmental Health
- Neuroscience
- Pediatrics
Background:
- Mental retardation is a significant public health concern.
- The etiology of mental retardation remains unknown in many cases.
- Lead exposure is a known neurotoxin with potential developmental impacts.
Purpose of the Study:
- To investigate the association between blood lead levels and unexplained mental retardation in children.
- To assess the activity of delta-aminolevulinic acid dehydratase (delta-ALAD) in relation to lead exposure.
- To explore lead's potential role in the etiology of mental retardation.
Main Methods:
- Whole blood lead levels and red cell delta-ALAD activity were measured in 60 children with mental retardation of unknown etiology.
- Control groups included 30 normal children and 30 children with known mental retardation.
- Statistical analysis compared lead values and delta-ALAD activity between groups.
Main Results:
- Children with unexplained mental retardation had significantly higher blood lead levels than both control groups (P < 0.001).
- Reduced delta-ALAD activity was observed in patients with blood lead levels ≥ 40 microgram/dl.
- Over 20% of children with unexplained mental retardation showed evidence of significant lead exposure.
Conclusions:
- Significant lead exposure is indicated in a notable percentage of children with unexplained mental retardation.
- Lead exposure may play a role in the etiology of mental retardation.
- Further research is warranted to elucidate the impact of lead on cognitive development.
Abstract:
In 60 children with mental retardation of unknown etiology, the whole blood lead, as well as the activity of the red cell delta-aminolevulinic acid dehydratase (delta-ALAD), was measured. Thirty normal children and 30 with mental retardation of known etiology were used as controls. The lead values were found significantly higher in the study patients compared with both control groups (P less than 0.001). The delta-ALAD activity in the 14 patients with blood lead levels greater than or equal to 40 microgram/dl, was significantly reduced compared with the normal controls (P less than 0.001) and the mentally retarded controls (P less than 0.01). In more than 20% of the patients with mental retardation of unknown etiology, indications of significant exposure to lead were found. There was no difference in blood lead values between children from cities and those from rural areas. The possible role of lead in the etiology of mental retardation is discussed.