MATERNAL CONTAMINANT EXPOSURE IN CANADA: CONVENIENCE AND RANDOM SAMPLING COMPARISONS
Bibliographic record
Abstract
Background / Aims Recently the Canadian Health Measures Survey (CHMS) and a Health Canada study have examined in southern Canada a similar group of contaminants in women of child bearing age (WCBA) and mothers, respectively. This paper will examine the differences in these contaminants between a random sample of WCBA and a convenience sample of mothers, both Canadian born and non-Canadian born. Methods The CHMS a national health survey of over 5000 individuals has concentrations of contaminants in women of child bearing age in a stratified random population sample (n=285, 2007-2009). The Health Canada study has collected a convenience sample of first time mothers from five Canadian centres and includes both Canadian born and non-Canadian born mothers (n=125, 2005-2007). Concentrations of total mercury, lead, several polychlorinated biphenyl congeners, and various organochlorine pesticides are compared. Results Initial data analysis has found that the concentrations for many of these contaminants are age dependent, increasing with age and that mothers born in Canada had lower concentrations of many contaminants compared to mothers not born in Canada. The concentration of many of these contaminants in WCBA from the CHMS is intermediate between these two groups of mothers. Further analyses of the WCBA will explore the differences seen in the Canadian vs non-Canadian born mothers to see if there are contaminant pattern differences between mothers and WCBA. Conclusions Both women of child bearing age and first time mothers have a similar suite of contaminants in their blood. In-depth analysis has found that there are significant differences between mothers born in Canada and mothers born outside of Canada.
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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 | 0.006 | 0.017 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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".