Environmental and potential human health legacies of non-industrial sources of lead in a Canadian urban landscape – the case study of St John's, Newfoundland
Bibliographic record
Abstract
Residential soil and house dust were collected in St John's to assess the levels of lead exposure and potential human health risk. Although St John's does not have an identified, major point source for lead, nor is it a heavily industrialized or populated city, 51% of all analysed soil samples (n = 1231) exceeded the Canadian Council of Ministers of the Environment (CCME) residential soil lead guideline of 140 ppm, 26% exceeded the 400 ppm United States Environmental Protection Agency (US EPA) guideline for soil in children's play areas, and 9% exceeded the 1200 ppm US EPA guideline for soil outside of play areas. High soil lead concentrations, particularly those above 1200 ppm, are clustered in the older downtown core. Samples located along exterior house walls (dripline) have the highest mean soil lead concentrations, followed by open spaces in yards (ambient) and then roadside sites. Lead in dripline soil samples from older housing stock is sourced to lead-bearing paint. Lead from both dripline and ambient samples on properties developed between the 1940s and 1980s have a mixture of sources including coal ash, paint, and leaded gasoline. Approximately 12% of analysed house dust samples (n = 96) exceeded the US EPA guidelines for lead in indoor dust, all from pre-1950s housing and all associated with dripline soil lead concentrations greater than 900 ppm. Human health risk predictions suggest that, although the wider St John's community may not be at risk of adverse health effects, children living in pre-1970s housing may be exposed to increased risk.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 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".