Characterization of particle exposure during tunnel excavation by tunnel boring machines.
Tunnel boring machines (TBMs) are used to excavate tunnels in a manner where the rock is constantly penetrated with rotating cutter heads. Fine particles of the rock minerals are thereby generated. Workers on and in the vicinity of the TBM are exposed to particulate matter (PM) consisting of bedrock...
| Published in: | Annals of Work Exposures & Health Vol. 68; no. 7; pp. 713 - 725 |
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| Main Authors: | , , , , , , , , |
| Format: | equations & formulas pictorial research tables/charts Journal Article |
| Published: |
Oxford University Press / USA
Aug2024
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=179110816&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 179110816 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 23987308 KJ1E jtl: Annals of Work Exposures & Health issn: 23987308 maglogo: N pubinfo: dt: Aug2024 vid: 68 iid: 7 pid: 622 pub: Oxford University Press / USA artinfo: ui: 179110816 179110816 179110816 10.1093/annweh/wxae041 179110816 ppf: 713 ppct: 12 formats: fmt: – @attributes: type: T – @attributes: type: P tig: atl: Characterization of particle exposure during tunnel excavation by tunnel boring machines. aug: au: Ervik, Torunn K Leite, Mimmi Weinbruch, Stephan Nordby, Karl-Christian Ellingsen, Dag G Ulvestad, Bente Dahl, Kari Berlinger, Balazs Skaugset, Nils Petter affil: National Institute of Occupational Health , P.O. Box 5330, Majorstuen, 0304 Oslo , Norway sug: subj: Air Pollutants, Occupational Occupational Exposure Particulate Matter Construction Industry Equipment and Supplies Inhalation Exposure Silicon Compounds Respiratory Tract Diseases Environmental Monitoring Human Particle Size X-Rays Dust Funding Source Microscopy, Electron ab: Tunnel boring machines (TBMs) are used to excavate tunnels in a manner where the rock is constantly penetrated with rotating cutter heads. Fine particles of the rock minerals are thereby generated. Workers on and in the vicinity of the TBM are exposed to particulate matter (PM) consisting of bedrock minerals including α-quartz. Exposure to respirable α-quartz remains a concern because of the respiratory diseases associated with this exposure. The particle size distribution of PM and α-quartz is of special importance because of its influence on adverse health effects, monitoring and control strategies as well as accurate quantification of α-quartz concentrations. The major aim of our study was therefore to investigate the particle size distribution of airborne PM and α-quartz generated during tunnel excavation using TBMs in an area dominated by gneiss, a metamorphic type of rock. Sioutas cascade impactors were used to collect personal samples on 3 separate days. The impactor fractionates the dust in 5 size fractions, from 10 µm down to below 0.25 µm. The filters were weighted, and the α-quartz concentrations were quantified using X-ray diffraction (XRD) analysis and the NIOSH 7500 method on the 5 size fractions. Other minerals were determined using Rietveld refinement XRD analysis. The size and elemental composition of individual particles were investigated by scanning electron microscopy. The majority of PM mass was collected on the first 3 stages (aerodynamic diameter = 10 to 0.5 µm) of the Sioutas cascade impactor. No observable differences were found for the size distribution of the collected PM and α-quartz for the 3 sampling days nor the various work tasks. However, the α-quartz proportion varied for the 3 sampling days demonstrating a dependence on geology. The collected α-quartz consisted of more particles with sizes below 1 µm than the calibration material, which most likely affected the accuracy of the measured respirable α-quartz concentrations. This potential systematic error is important to keep in mind when analyzing α-quartz from occupational samples. Knowledge of the particle size distribution is also important for control measures, which should target particle sizes that efficiently capture the respirable α-quartz concentration. pubtype: Academic Journal doctype: equations & formulas pictorial research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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