DDE, a Degradation Product of DDT, and Duration of Lactation in a Highly Exposed Area of Mexico
Bibliographic record
Abstract
BACKGROUND: Higher levels of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), the major degradation product of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), have been related to shorter duration of breast-feeding in previous studies. If DDE truly shortens lactation, this has public health importance regarding infant mortality and the use of DDT for malaria control. OBJECTIVE: Our aim was to assess the relationship of maternal DDE concentrations with length of subsequent lactation. METHODS: We conducted a relatively large study in a highly exposed area of Mexico. We followed 784 mother-son pairs to determine length of lactation. DDE and DDT were measured in maternal serum obtained within a day of delivery. We fit proportional hazard models with and without stratifying by previous breast-feeding, because an association of DDE with duration of lactation among those who breast-fed previously could be attributed to a noncausal mechanism. RESULTS: Compared with those with DDE concentrations < or = 3.00 microg/g, the adjusted hazard ratios of weaning according to DDE category were, for concentrations 3.01-6.00 microg/g, 1.27 [95% confidence interval (CI), 1.04-1.55]; for concentrations 6.01-9.00 microg/g, 1.23 (95% CI, 0.92-1.63); and for concentrations > 9.00 microg/g, 1.17 (95% CI, 0.92-1.49). The corresponding ratios for women who previously breast-fed were 1.40 (95% CI, 1.06-1.87); 1.91 (95% CI, 1.24-2.93); and 1.76 (95% CI, 1.22-2.53). Those for women who had not breast-fed previously were 1.14 (95% CI, 0.86-1.52); 0.90 (95% CI, 0.61-1.31); and 0.91 (95% CI, 0.66-1.26). CONCLUSIONS: Data from our relatively large study in a highly exposed area of Mexico did not support the hypothesis that exposure to DDE shortens length of lactation. The association seen in women who previously breast-fed was likely attributed to a noncausal mechanism. Nonetheless, whether DDT has other important adverse effects on humans is still an open question.
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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 | 0.001 | 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".