Silica And Asbestos Exposure At Work And Risk Of Bladder Cancer In Canadian Men: A Population-Based Case-Control Study
Bibliographic record
Abstract
Introduction: Silica and asbestos are prevalent occupational exposures worldwide and are recognized lung carcinogens by the International Agency for Research on Cancer. Clearance of inhaled silica particles and asbestos fibers from the lungs may lead to translocation to sites such as the bladder where they may also initiate carcinogenesis. As few studies have evaluated associations between these exposures and bladder cancer, we sought to address this research gap using data from a Canadian population-based case-control study. Methods: This study included 658 cases and 1360 age-frequency matched controls recruited by the National Enhanced Cancer Surveillance System from seven provinces between 1994 and 1997. Concentration, frequency and a measure of the reliability of both silica and asbestos exposure was assigned to each job, based on lifetime occupational histories, using a combination of job-exposure matrices and expert review. Exposures were modelled as ever-never, highest attained concentration, duration, frequency and cumulative exposure. Odds ratios (OR) and their 95% confidence intervals (95% CI) were determined from logistic regression adjusted for age, province, proxy, pack-years and occupational exposures. Results: Relative to unexposed, increased risk of bladder cancer was observed among men with (i) 27 or more years of exposure to low concentrations of silica (OR: 1.38 95% CI: 1.00 – 1.91) and (ii) those in the upper tertile of cumulative silica exposure (1.45, 1.06 – 1.98). For asbestos the results were less consistent with an exposure-response relationship. However, when compared to those with no occupational exposure, increased risks of bladder cancer were observed among those exposed for 5-30% of work time (1.45, 1.06-1.98), < 10 years of exposure at low concentrations (1.75, 1.10-2.77) and the lower tertile of cumulative exposure (1.64, 1.04 – 2.59). Conclusions: Occupational exposure to silica and asbestos may increase the risk of bladder cancer.
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 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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".