Interpretation of Urinary Concentrations of Pyrethroid Metabolites in the Canadian Population in a Risk Context: Associated Factors and Comparison to Biomonitoring Equivalents
Bibliographic record
Abstract
Pyrethroids are extensively used in agricultural, commercial and residential pest control, and are implicated in adverse health outcomes in humans. We evaluated the associations between socio-demographic and dietary factors and urinary concentrations of pyrethroid metabolites in the Canadian general population using data collected under the Canadian Health Measures Survey (CHMS) cycles 1 and 2 (2007-11), and assessed the data in a risk context using the screening-level biomonitoring equivalents for 3-phenoxybenzoic acid (3-PBA), a common metabolite of several pyrethroids. Data from CHMS cycles 1 and 2 were combined for the analyses. Regression analysis revealed significant (p<0.05) age-dependent differences in the least-square geometric mean (LSGM) concentrations of the sum of all measured pyrethroid metabolites, or 3-PBA (LSGM for 20-39 years > 12-19 years). The concentrations were also associated with sex (females > males), country of birth (other than Canada > Canada), body mass index (normal weight > obese), season (fall > summer), use of home/yard pesticides or lice/flea control products (yes > no), and frequency of consumption of vegetables (high > low) and starchy roots (low > high). The geometric mean concentrations of 3-PBA for all age and sex groups from CHMS cycles 1 and 2 did not exceed the Tier 1 screening value of 1.7 µg/L based on the most stringent of the biomonitoring equivalents derived for the chronic dietary RfD (USEPA) and ADI (WHO/FAO/EC) suggesting that the cumulative exposures to pyrethroids in Canadians are low relative to guidance values, and existence of a margin of safety. Additional data on pyrethroid metabolites in Canadians from CHMS cycle 5 (2016-17) and cycle 6 (2018-19) will support an assessment of trends in exposure and future evaluation of risks.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".