Blood manganese and cognitive and motor skills at age 6-7 in Canadian cohort GESTE
Bibliographic record
Abstract
Abstract Background: Increasing evidence suggests that high exposure to manganese (Mn) may impair brain development. In Canada, Mn exposure comes from several environmental sources and the most common is drinking water. Our objective was to examine the relationship between blood Mn and psychomotor skills in school-aged children from the Eastern Townships, Qc, Canada. In addition, we examined the association of Mn with Attention-Deficit Hyperactivity Disorder (ADHD) diagnosis in our study group.Methods: Children were recruited at birth (through their mother) and followed prospectively. At 6-7 years of age, 210 children provided a blood sample for manganese testing and underwent a battery of neuropsychological tests. This battery assessed several major cognitive domains including general intelligence, attention and others via subtests from the Wechsler Intelligence Scale for Children – IV (WISC-IV), the Developmental NEuroPSYchological Assessment-II (NEPSYII) and the Test of Everyday Attention for Children (TEACH). Parents were asked if their child had ever received a physician diagnosis of ADHD. Blood was analysed by inductively coupled plasma mass spectrometry. Multivariate statistic modelling was used to control for potential confounding factors, including blood lead.Results: Median blood Mn was 9.9 µg/L (range 4.7 – 21.4 µg/L). The Design Copying – Fine motor score of the NEPSYII was positively associated with blood Mn (linear model β: 0.17 [95% Confidence Interval: 0.03 to 0.32]; adjusted model β: 0.16 [95% Confidence Interval 0.01 to 0.30]). Blood Mn was not associated with diagnosis of ADHD. Sex-stratified analyses indicated potential effect modification by child sex such that manganese had a beneficial association on the Score DT test (a measure of sustained attention), but only among boys (β: 0.29, [95% confidence interval: 0.098 to 0.49]) Conclusions: In agreement with studies from areas with similar environmental Mn levels, our study suggests that blood Mn level does not have wide-ranging associations with cognitive functions, psychomotor skills, or a diagnosis/suspicion of ADHD in school-aged children. To resolve the controversy about toxicity of environmental Mn on the developing brain, further studies should simultaneously focus on several biomarkers of Mn exposure, potential lifestyle protective factors, as well as brain imaging.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".