Evaluation of control strategies for reducing occupational exposure to trichloramine in indoor swimming pools
Notice bibliographique
Résumé
Studies have shown that swimming pool workers often exhibit symptoms linked to exposure to disinfection by-products (DBPs), particularly trichloramine (TCA). However, current studies on occupational exposure to DBPs, including TCA, lack standardized sampling methods. Improving exposure assessment requires harmonizing sampling strategies and considering variations within and between pools, as well as spatial, temporal, personal, and environmental factors. This thesis aims to characterize occupational exposures to TCA in indoor swimming pools, assess the associated health outcomes and investigate strategies to reduce these exposures. The specific objectives were: (1) to evaluate TCA sampling methods, comparing collection strategies to evaluate airborne TCA levels and investigate temporal and spatial variations in indoor pools; (2) to model TCA exposure, using comprehensive sampling and empirical modeling of DBPs in water and air, and estimate occupational exposure to airborne TCA using the well-mixed model (WMM); (3) to assess the health outcomes of TCA exposure on pool workers and compare results from stationary and personal sampling. For the first objective, both laboratory experiments and field samplings were conducted, including measurements in multiple pools. TCA was generated in a dedicated laboratory setup, with air samplings adapted from the Hery method. In swimming pools, 2h-air samples were made in diverse locations and using various sampling trains. Besides 2h samples, 4h-, 6h- and 8h samples were collected using an innovative sampling cassette assembly composed of three filters and a separable pre-filter. For the second objective, a database of air and water measurements from four pools was created, and statistical analyses were performed to assess the association between DBPs and explanatory variables. In addition, the WMM, a model used within the IH MOD tool, was applied to estimate TCA concentrations. In the third objective, environmental and personal samplings were collected to explore the relationship between TCA exposure and respiratory health effects in pool workers. Data from six indoor pools and personal measurements from 60 workers were analyzed. Respiratory outcomes were assessed through questionnaires and respiratory tests, including FENO assessments, conducted before and after shifts. Laboratory studies showed that TCA concentrations exceeding 1 mg/m3 resulted in significant deposition on the second filter, indicating potential material loss. Using a separable cassette assembly prevented overestimation of TCA levels, supporting its use in exposure assessments. Field studies identified significant daily variations in TCA concentrations, challenging the adequacy of 2-hour samples in estimating occupational exposure. A full-shift sampling strategy with three filters was proposed as a more accurate method for time-weighted average TCA exposure assessments. Findings from four chlorinated pools revealed a significant impact of bather attendance on air DBPs levels, with increases in TCA concentrations. Models for airborne DBPs, using parameters like CO2 and relative humidity, showed strong predictive capacity for day-to-day monitoring. The WMM, updated to include swimmer numbers, proved useful tool for anticipating TCA levels. The research highlighted significant health concerns associated with high TCA levels in indoor pools, exceeding previously reported levels. The study emphasized the prevalence of work-related symptoms among pool workers, particularly eye irritation, underscoring the need for preventive measures to protect their health.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,003 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 source (Gemma direct ou Codex distillé), 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 ».