An Assessment of Health Risks Resulting From an Environmental Exposure to Organophosphates Pesticides Using Biological Reference Values
Bibliographic record
Abstract
P-781 Introduction: Biological reference values (BRV) under the form of urinary amounts of methylphosphates (MP) and ethylphosphates (EP) metabolites have been proposed recently to assess health risks resulting from exposure to the organophosphate (OP) insecticides in workers. The present study is an application of a toxicological approach used to derive these BRV to the context of an environmental exposure to OP pesticides to assess the health risks in a group of children of a suburban region of the Province of Quebec, Canada. Methods: 89 children provided multiple first-morning complete voids (n = 442 in total), which corresponded more or less to the amounts accumulated during the prior 12 h. It was also considered that all the OP exposure occurred over an 8-h period between 24 and 16 h prior to sampling. Finally, it was conservatively assumed that all the MP and EP urinary metabolites measured resulted from the exposure to azinphosmethyl and chlorpyrifos, respectively, which are among the most toxic OP insecticides. An assessment of health risks was then made by comparing the observed 12-h cumulative urinary amounts of MP and EP metabolites with an adjusted value for each BRV, reflecting the excretion of MP and EP metabolites during the 12-h period before sampling. Results: The amounts of MP and EP in the 442 urine samples were compared with the adjusted BRV (ABRV) of 63 and 32 nmol/kg of body weight, respectively. On average (± SD), the fraction of the observed exposure to the ABRV was 0.072 ± 0.107 and 0.015 ± 0.026 for MP and EP, respectively. Only one samples presented an MP value exceeding its ABRV, while the maximal fraction of the ABRV for EP was 0.31. Considering both MP and EP together to assess the additive risks of all OPs, again only one sample presented a sum of the two ABRV fractions exceeding the value of 1; the average value was 0.087 ± 0.119. Discussion and Conclusion: The BRV were determined using a conservative modeling approach, while the observed exposure probably did not represent the most conservative exposure scenario. Also, it is very unlikely that all the observed exposure came only from APM and CPS and other less toxic OP obviously contributed to the observed exposure. Therefore, the overall results of this risk assessment are not considered particularly preoccupying.
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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 | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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".