Retrospective Assessment of Respirable Quartz Exposure for a Silicosis Study of the Industrial Sand Industry
Notice bibliographique
Résumé
Background: In 2016, the OSHA PEL for crystalline silica was reduced, renewing interest in evaluating risk of silicosis from occupational exposures. The industrial sand industry, which deals with high-purity quartz sands, is the setting for a current epidemiologic investigation of silicosis risk and progression. In support of that investigation, respirable quartz (RQ) exposures were retrospectively estimated for 67 workers with silicosis and 167 matched control workers from 21 industrial sand plants, in which some started work as early as 1929. Methods: A job exposure matrix (JEM) was constructed by integrating a modern (post-1970) RQ exposure database containing more than 40000 measurements with archival particle count exposure data from a 1947 survey. A simulation algorithm was used to develop a conversion factor to convert the archival particle count data into modern measures of RQ by randomly generating 100000 virtual dust particles of varying diameters corresponding to the size distributions of 14 archival particle size distribution samples. The equivalent respirable mass and particle counts of the virtual particles were calculated, totalled, and ratioed to derive the conversion factor. The JEM was integrated with individual job histories to calculate average and cumulative exposure for each case and control. Multiple exposure estimates were derived for unprotected exposures as well as for exposures adjusted for estimated respiratory protective equipment use and efficiency. Results: The mean of the count to respirable mass conversion factors derived from 14 archival particle size samples was 157 µg m-3 per mppcf (SD: 42; range: 96-263) with no statistical difference across process areas (drying, screening, vibrating, binning, bulk loading, bagging), P = 0.29. The JEM demonstrated an industry-wide decrease in prevailing exposures to RQ of up to about 2 orders of magnitude from the distant (1929) to the recent (2012) past. Unadjusted cumulative exposures for cases and controls were statistically different (P < 0.001) with respective medians (range) of 3764 µg m-3 year (221-25121) and 1595 µg m-3 year (0-16446). Adjustment of exposure for use of respiratory protection showed modest reductions in estimated exposure: median adjusted cumulative exposures assuming a protection factor of 5 were 86% and 77% of the unadjusted values for cases and controls, respectively. Conclusions: The industrial sand industry offers a unique setting for examination of silicosis risk because of the high silica content of industrial sand and a long history of radiographic silicosis surveillance of industry workers. However, the great majority of silicosis cases in this industry are found among former workers and are associated with exposures occurring in the distant past, which necessitates extensive retrospective exposure assessment and increases the likelihood of exposure misclassification. Nonetheless, the estimated cumulative exposures for silicosis cases and controls in this work were significantly different, with the median cumulative exposure for cases being more than twice that of their matched controls.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».