Comparing the role of silica particle size with mineral fiber geometry in the release of superoxide from rat alveolar macrophages

Ohyama, Masayuki; Tachi, Hideki; Minejima, Chika; Kameda, Takayuki

doi:10.2131/jts.39.551

Cited by 4 publications

(3 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We considered to the inconsistency that the fiber length affects to release superoxide from macrophages further than the fiber surface characteristics. In fact, we previously demonstrated that the activity of mineral fiber to induce superoxide release from macrophages was approximately 8.3 times greater than that of silica [12].…”

Section: Discussionmentioning

confidence: 94%

See 1 more Smart Citation

Comparing Heat-treated Silica Particle with Silica Particles for the Ability to Induce Superoxide Release from Rat Alveolar Macrophages

Ohyama¹,

Tachi²,

Minejima³

et al. 2014

J Clin Toxicol

Self Cite

View full text Add to dashboard Cite

Crystalline silica can devitrify with the formation of cristobalite and other crystalline silica species when exposed to prolonged high temperatures, which is of potential concern because crystalline silica is classified as carcinogenic. Silica particles activate macrophages to release oxidants, which contribute to inflammation and injury in the lower respiratory tract. Our aim was to compare silica particles with heat-treated silica particles for their ability to induce superoxide release from rat alveolar macrophages. We estimated the ability of four types of silica particle samples and heat-treated silica particles with different number average particle diameter to induce lucigenin-dependent chemiluminescence (CL) from macrophages based on the number of silica particles. A strong positive correlation was observed between particle diameter and the ability to induce CL in both the silica and heat-treated silica samples. Moreover, the ability of heat-treated silica samples to induce CL was approximately 43% of that of the silica samples. These results suggest that heat-treated silica reduces superoxide release from macrophages, and that the heat-treated reduces the biological effects of silica.

show abstract

Section: Discussionmentioning

confidence: 94%

“…The method for measuring lucigenin-dependent CL from the macrophages exposed to various mineral samples has been described in previous reports [9][10][11][12].…”

Section: Measurementsmentioning

confidence: 99%

Comparing Heat-treated Silica Particle with Silica Particles for the Ability to Induce Superoxide Release from Rat Alveolar Macrophages

Ohyama¹,

Tachi²,

Minejima³

et al. 2014

J Clin Toxicol

Self Cite

View full text Add to dashboard Cite

show abstract

“…As efforts to reduce incidence of silicosis continue, knowledge of the silica content of specific ranges of particle size will be useful for several reasons: 1) as noted by Qi et al (2015), dust control technologies can be best developed and utilized when the size distribution of the dust and the silica content of different particle size ranges are well understood; 2) the analytical methods used to quantify silica in dust samples are most accurate when the size distribution of silica within the dust sample is closely matched to the size distribution of the calibration material (Huggins et al , 1985; Pickard et al , 1985); and 3) once inhaled, silica particles of distinct sizes may have variable impacts on inflammation and the development of fibrosis (Goldstein and Webster, 1966; Wiessner et al , 1989; Mischler, 2013; Ohyama et al , 2014). This may be further impacted by the enhanced penetration of smaller particles in the alveolar region of the lungs (Bartley and Vincent, 2011).…”

Section: Introductionmentioning

confidence: 99%

Characterizing Particle Size Distributions of Crystalline Silica in Gold Mine Dust

Chubb

Cauda

2017

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

Dust containing crystalline silica is common in mining environments in the U.S. and around the world. The exposure to respirable crystalline silica remains an important occupational issue and it can lead to the development of silicosis and other respiratory diseases. Little has been done with regard to the characterization of the crystalline silica content of specific particle sizes of mine-generated dust. Such characterization could improve monitoring techniques and control technologies for crystalline silica, decreasing worker exposure to silica and preventing future incidence of silicosis.Three gold mine dust samples were aerosolized in a laboratory chamber. Particle size-specific samples were collected for gravimetric analysis and for quantification of silica using the Microorifice Uniform Deposit Impactor (MOUDI). Dust size distributions were characterized via aerodynamic and scanning mobility particle sizers (APS, SMPS) and gravimetrically via the MOUDI. Silica size distributions were constructed using gravimetric data from the MOUDI and proportional silica content corresponding to each size range of particles collected by the MOUDI, as determined via X-ray diffraction and infrared spectroscopic quantification of silica.Results indicate that silica does not comprise a uniform proportion of total dust across all particle sizes and that the size distributions of a given dust and its silica component are similar but not equivalent. Additional research characterizing the silica content of dusts from a variety of mine types and other occupational environments is necessary in order to ascertain trends that could be beneficial in developing better monitoring and control strategies.

show abstract

Characterization of particle exposure during tunnel excavation by tunnel boring machines

Ervik,

Leite,

Weinbruch

et al. 2024

Annals of Work Exposures and Health

View full text Add to dashboard Cite

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.

show abstract

Comparing the role of silica particle size with mineral fiber geometry in the release of superoxide from rat alveolar macrophages

Cited by 4 publications

References 33 publications

Comparing Heat-treated Silica Particle with Silica Particles for the Ability to Induce Superoxide Release from Rat Alveolar Macrophages

Comparing Heat-treated Silica Particle with Silica Particles for the Ability to Induce Superoxide Release from Rat Alveolar Macrophages

Characterizing Particle Size Distributions of Crystalline Silica in Gold Mine Dust

Characterization of particle exposure during tunnel excavation by tunnel boring machines

Contact Info

Product

Resources

About