Bibliographic record
Abstract
Studies have linked long-term inhalation of radon progeny or radon daughters with adverse health effects such as lung cancer. Although the risk is very low when radon is diluted to extremely low concentrations in the open, radon in underground mines can accumulate up to dangerous concentrations and may cause substantial health damage after long-term exposure. Radon can be found in certain types of geology, such as granite and volcanic soils, as well as aluminous shales. Likewise, low concentrations of this gas can be expected in sedimentary rocks. In October 1988, Ontario’s Mining Legislative Review Committee (MLRC) approved regulation to control the higher levels of radon progeny found in some of the non-uranium mines. Several sections (287 to 293) were amended to Regulation 854 (Ministry of Labour 2012). In sections 287 to 293, ‘radon daughters’ means polonium-218 (RaA), lead-214 (RaB), bismuth-214 (RaC) and polonium-214 (RaC’). The unit of radon daughter concentration is expressed in working level (WL) or working level month (WLM). The maximum allowable exposure each month for one year to maintain annual exposures below 1 WLM is 0.083 WL and the ceiling concentration is 0.33 WL. Section 289 describes air sampling protocols for radon daughters. This paper presents the results of radon assessments conducted from 2004-2012 at various locations in 28 Ontario’s non-uranium underground mines. A total of 325 measurements were conducted and results indicated that radon progeny concentrations measured ranged from 0.000-0.070 WL. These were all below the maximum allowable exposure each month for one year of 0.083 WL to maintain annual exposure of 1 WLM; 97% of the measurements were within 0.000-0.030 WL, 2% were within 0.031-0.060 WL, and 1% was within 0.061-0.10 (or 0.070) WL. At these concentrations, actions that have to be conducted by the non-uranium underground mines range from annual assessment by a competent person (<0.03 WL), annual sampling of workplaces (0.031-0.06 WL), and quarterly sampling of workplaces (0.061-0.10 WL). Maintaining good ventilation in Ontario’s non-uranium underground mines may have contributed to the generally low radon progeny concentration levels measured from 2004-2012.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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 source (direct Gemma or distilled Codex), 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".