Organophosphate pesticide metabolite concentrations in a pregnancy cohort: daily variability, and predictors of exposure
Bibliographic record
Abstract
Organophosphates (OP) are commonly used agricultural pesticides. In 2009–2010, 80 pregnant women were recruited from Ottawa, Canada for the Plastics and Personal-care Product use in Pregnancy (P4) Study. A subset (n = 25) collected multiple spot urines (up to 10 each; total n = 431) over two 24-h periods in early pregnancy - one weekday and weekend day - while logging their food consumption beginning 24 h prior to the first urine void and continuing through the following 24-h urine collection period. Urine samples (n = 431 samples) were analyzed for six dialkyl OP metabolites, dimethyldithiophosphate (DMDTP), dimethylthiophosphate (DMTP), dimethylphosphate (DMP), diethyldithiophosphate (DEDTP), diethylthiophosphate (DETP), and diethylphosphate (DEP). This is the first study to look at within day variability of OP pesticide metabolites. Intra-class correlation coefficients (ICC's) were highest for DMP on weekend days (0.82) and lowest for DEDTP (0.35). Using a single spot urine to predict high urinary concentrations compared to the geometric mean of the participant's remaining samples for that day showed median sensitivities ranging from 67 to 87 % (weekday) and 73–81 % (weekend). This study was underpowered to see clear group differences; however molar sum dialkyl phosphate (DAP) metabolite concentrations over the 24 h weekday collection period increased or remained stable in urine samples collected >6–12 h post-consumption of most food groups. We encourage future research with a larger sample size and more diverse participants, with a focus on OPs that are increasing or remaining stable over time including DEP and metabolites of pyrethroids, and neonicotinoids. • High detection rates were observed for dimethylthiophosphate (DMTP, 96 %), dimethylphosphate (DMP, 94 %), diethylphosphate (DEP, 89 %), and diethylthiophosphate (DETP, 77 %) among 431 urine samples taken from 25 pregnant women, over two 24-hr periods, early in pregnancy. • Intraclass correlation coefficients for most organophosphate showed moderate reproducibility within a 24 h period but were weaker across a weekday and weekend day. • Molar sum dialkyl phosphate (DAP) concentrations peaked 6–12 h post-consumption of fruits and vegetables.
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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".