Selective Detection of Airborne Asbestos Fibers Using Protein-Based Fluorescent Probes

Ishida, Takenori; Alexandrov, Maxym; Nishimura, Tomoki; Minakawa, Kenji; Hirota, Ryuichi; Sekiguchi, Kazuma; Kohyama, Norihiko; Kuroda, Akio

doi:10.1021/es902395h

Cited by 18 publications

(26 citation statements)

References 13 publications

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“…However, a recent study demonstrated that the DksA protein from Escherichia coli binds strongly and selectively to chrysotile, the most commonly used industrial form of asbestos, which now makes it possible to visualize the asbestos fibers in water by fluorescence microscopy. 4,32 In addition, the protein promotes stability of a chrysotile suspension by introducing steric repulsions between fibers. 33 …”

Section: Introductionmentioning

confidence: 99%

In Situ Liquid Cell Observations of Asbestos Fiber Diffusion in Water

Ortiz

et al. 2015

Environ. Sci. Technol.

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We present real-time observations of the diffusion of individual asbestos fibers in water. We first scaled up a technique for fluorescent tagging and imaging of chrysotile asbestos fibers and prepared samples with a distribution of fiber lengths ranging from 1 to 20 μm. Experiments were then conducted by placing a 20, 100, or 150 ppm solution of these fibers in a liquid cell mounted on a spinning-disk confocal microscope. Using automated elliptical-particle detection methods, we determined the translation and rotation and two-dimensional (2D) trajectories of thousands of diffusing chrysotile fibers. We find that fiber diffusion is size-dependent and in reasonable agreement with theoretical predictions for the Brownian motion of rods. This agreement is remarkable given that experiments involved non-idealized particles at environmentally relevant concentrations in a confined cell, in which particle–particle and particle–wall interactions might be expected to cause deviations from theory. Experiments also confirmed that highly elongated chrysotile fibers exhibit anisotropic diffusion at short time scales, a predicted effect that may have consequences for aggregate formation and transport of asbestos in confined spaces. The examined fibers vary greatly in their lengths and were prepared from natural chrysotile. Our findings thus indicate that the diffusion rates of a wide range of natural colloidal particles can be predicted from theory, so long as the particle aspect ratio is properly taken into account. This is an important first step for understanding aggregate formation and transport of non-spherical contaminant particles, in the environment and in vivo.

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Section: Introductionmentioning

confidence: 99%

In Situ Liquid Cell Observations of Asbestos Fiber Diffusion in Water

Ortiz

et al. 2015

Environ. Sci. Technol.

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“…This has led to proposals for new selective methods to detect asbestos in concrete materials [30,31].…”

Section: Ndmentioning

confidence: 99%

Characterization of Thermochemical Inactivation of Asbestos Containing Wastes and Recycling the Mineral Residues in Cement Products

Yvon

Sharrock

2011

Waste Biomass Valor

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Asbestos Containing Wastes (ACW) were mixed with chemical additives and heated with microwaves. Eternit, Progypsol and Spray coated Amosite were thermo-chemically treated and the mineral residues recycled in mortar. Samples were analysed before and after thermal treatment by Scanning Electron Miscroscopy with Field Emission Gun (SEM FEG) and Energy Dispersive X-ray analysis (EDX) coupled to the SEM FEG. Mineralogy was examined by microprobe. X Ray diffraction (XRD) was used to identify the crystal lattice of products before and after melting. Additives such as borates, phosphates and sodium carbonate were introduced to lower the fusion temperatures and the treatment costs. Thermogravimetric analysis and differential scanning calorimetry were used to estimate melting effects due to the additives. EPR spectroscopy was used to study the environment of iron ions embedded on asbestos surfaces and demonstrate fiber transformation to a more isotropic phase. Magnesium silicates (serpentine group) were found in Eternit and Progypsol samples, and iron silicates (amphibole group) in Spray Coated Amosite samples. Observations by SEM illustrate differences in the structure between raw and treated materials but elemental analyses show the same chemical compositions. XRD patterns confirm the transformation of asbestos fibers into other crystalline materials. Borates are most effective for lowering the temperature of thermal transformation. The ground mixtures begin to melt at 900°C with borates compared to other melting products where the melting temperature is around 1,000-1,100°C. Heating with fusion additives allows irreversible transformation of the asbestos fibrous structure and recycling of the residues as filling materials in mortars. Thermal treatment seems to be the most effective process to transform and inactivate asbestos fibers from starting materials. Recycling treated ACW in mortar shows a decrease of mechanical properties when replacing cement or aggregate, but samples with 10 wt% ACW replacing aggregate show tensile strengths of 10 MPa, close to the value for the reference mortar with no ACW. Reuse of treated ACW would prevent stockpiling in hazardous waste landfills.

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“…Recognizing the limitations of these methods, the National Institute for Occupational Safety and Health has recently identified development of improved analytical methods for asbestos fibers as a strategic research goal (National Institute of Occupational Safety and Health (NIOSH) 2011). An emerging alternative to the commonly used analytical methods is fluorescence microscopy (FM), which employs fluorescent staining by specific asbestos-binding probes to both visualize asbestos and distinguish it from the unstained non-asbestos fibers (Kuroda et al 2008;Ishida et al 2010Ishida et al , 2012Ishida et al , 2013.…”

Section: Introductionmentioning

confidence: 99%

“…Compared to PCM, fluorescence microscopy provides a highly advanced capability to differentiate asbestos from non-asbestos fibers (Ishida et al 2010(Ishida et al , 2013. While this capability is below the level provided by electron microscopy, it does not require any advanced skills on the part of the operator.…”

Section: Introductionmentioning

confidence: 99%

Development of an automated asbestos counting software based on fluorescence microscopy

Alexandrov

Etsuko²,

Nishimura

et al. 2014

Environ Monit Assess

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An emerging alternative to the commonly used analytical methods for asbestos analysis is fluorescence microscopy (FM), which relies on highly specific asbestos-binding probes to distinguish asbestos from interfering non-asbestos fibers. However, all types of microscopic asbestos analysis require laborious examination of large number of fields of view and are prone to subjective errors and large variability between asbestos counts by different analysts and laboratories. A possible solution to these problems is automated counting of asbestos fibers by image analysis software, which would lower the cost and increase the reliability of asbestos testing. This study seeks to develop a fiber recognition and counting software for FM-based asbestos analysis. We discuss the main features of the developed software and the results of its testing. Software testing showed good correlation between automated and manual counts for the samples with medium and high fiber concentrations. At low fiber concentrations, the automated counts were less accurate, leading us to implement correction mode for automated counts. While the full automation of asbestos analysis would require further improvements in accuracy of fiber identification, the developed software could already assist professional asbestos analysts and record detailed fiber dimensions for the use in epidemiological research.

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Selective Detection of Airborne Asbestos Fibers Using Protein-Based Fluorescent Probes

Cited by 18 publications

References 13 publications

In Situ Liquid Cell Observations of Asbestos Fiber Diffusion in Water

In Situ Liquid Cell Observations of Asbestos Fiber Diffusion in Water

Characterization of Thermochemical Inactivation of Asbestos Containing Wastes and Recycling the Mineral Residues in Cement Products

Development of an automated asbestos counting software based on fluorescence microscopy

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