Potentially Toxic Elements andPersistent Organic Pollutionsin Hair:A Case Study of GreaterManchester
Notice bibliographique
Résumé
This study aimed to compare metal and Persistent Organic Pollutant (POP) concentrations in human hair clippings between metropolitan boroughs in Greater Manchester with different death rates. The official statistics for death rates for the years 2014-2017 and life expectancy data were used to identify nine boroughs in Greater Manchester for the study. Five of these are located predominantly in the northern and western parts of the city and reports the highest death rates. These boroughs were Bolton, Bury, Rochdale, Oldham and Wigan. Four other boroughs mainly in the central and southern parts of the city with low annual death rates were also identified for use in the work, namely Manchester, Trafford, Stockport and Salford. In each borough, two male and two female hairdresser shops were chosen for the sample collection, and hair of each type were combined to form in a composite hair sample through the application of the quarter and coning technique. Different hair washing methods were evaluated to determine their effect on the metal analyses of each hair sample, and the results were then compared with the published literature. For the remainder of the work reported in this study, a simple wash (deionised water wash) was selected as the sample preparation method. The metal contents were extracted by means of microwave digestion and analysed by ICP-OES. QUeChERS combined with a dispersive solid phase extraction method, was used to extract the POPs (i.e. polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)) and Gas Chromatography-Mass Spectroscopy was employed for the analysis. The focus was primarily on the contents of Cd, Pb, Ni, Cu, Zn and Mn analyses as far as the metallic elements were concerned, due to their toxic and carcinogenic behaviour in the human body. Various typical PCBs and PAHs were analysed in the POPs determinations. It was found that Pb and Zn were the two metallic elements with the highest concentrations in both the male and female hair samples in each borough from which hair samples were collected. For the PCB analyses, PCB 118 was present in much higher concentrations than the rest in both the female and male hair samples, and was also present to a much larger extent in the female hair samples than in the male samples. The three PCBs, apart from PCB118, had similar concentrations compared to each other in both the male and female hair samples. During the PAHs measurements, the analysis revealed that the PAH contents are dominated by these three compounds, i.e. acenaphthene, anthracene and naphthalene. In the female hair samples high values of acenaphthene were found. In the male hair samples, acenaphthene was also found in higher concentrations than any of the other PAHs, while naphthalene occurred in higher concentrations in the male hair samples than the rest of the PAHs, but was generally lower in concentration than acenaphthene. There was no discernible correlation between the death rates and/or life expectancy of the population in the various boroughs of Greater Manchester and the metallic element concentration profiles and POPs contents of the male and female hair samples.
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 | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,003 | 0,001 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 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 ».