Accuracy of electrical aerosol sensors measuring lung deposited surface area concentrations

Todea, Ana Maria; Beckmann, Stefanie; Kaminski, Heinz; Asbach, Christof

doi:10.1016/j.jaerosci.2015.07.003

Cited by 51 publications

(22 citation statements)

References 35 publications

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“…The NSAM (TSI, model 3550) was developed to provide the fractions of the geometric surface area concentrations of particles that would deposit in either the tracheobronchial or the alveolar region of the lung. A good agreement with the ICRP deposition model (7) has already been shown in several experimental and theoretical studies (16)(17)(18)(19)(20)(21)(22)(23) for various particles with sizes between 15 and 520 nm. Levin et al (24) investigated the behaviour of FMPS and ELPI compared to NSAM data for a set of aerosolized powder nanomaterials.…”

Section: Introductionsupporting

confidence: 75%

“…Thus, the reference CMD is an electrical mobility equivalent diameter. Although NSAM is not based on electrical migration of charged particles in an electric field, it was demonstrated that the charging efficiency, and thus the response of the instrument, scales with the electrical mobility diameter (45,46) . The reader's attention shall be drawn to the operation investigated for case "B", where aerosol sampling was performed directly in the plume, contrary to other situations considered in this paper in which aerosols were sampled in the surrounding area of the workers.…”

Section: Considerations Regarding the Reference Cmdmentioning

confidence: 99%

See 1 more Smart Citation

Combining NSAM and CPC concentrations to determine airborne nanoparticle count median diameter: Application to various laboratory and workplace aerosols

Bau

Payet

Toussaint

et al. 2018

Journal of Occupational and Environmental Hygiene

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Because nanomaterials have been increasingly developed and used in many technology and industry sectors over the last 20 years, an increasing number of workers is likely to be exposed to airborne nanoparticles. In addition, the question of the nanomaterial characteristics that should be assessed in epidemiological studies remains open. Thus, assessing occupational exposure to airborne nanoparticles will not only rely on mass concentration and chemical composition. Rather, key parameters, such as particle size, have to be included in measurement strategies. We previously proposed a methodology to estimate the Count Median Diameter (CMD) of an aerosol based on the simultaneous size-integrated measurement of two particle concentrations, lung-deposited surface area, and number, thanks to field-portable, commercially available aerosol instruments (Nanoparticle Surface Area Monitor/Condensation Particle Counter combination). In addition to previous work, this study investigates the case of various polydisperse metal oxides, organic oil, and salt particles with CMDs ranging from 16-410 nm. Once corrected, the CMDs derived from the NSAM/CPC agree within ±20% with regard to the reference electrical mobility equivalent diameter, regardless of aerosol composition, morphology, or geometric standard deviation (GSD). Furthermore, the field-applicability of the method was tested through 6 sets of experimental data stemming from workplace measurement campaigns where different materials were produced and handled (TiO, SiO, Ag, Multi-Walled Carbon Nanotubes-MWCNT), covering a range of CMDs between 40 and 190 nm. All situations considered, the approach based on the combination of a NSAM and a CPC leads to a satisfying estimation of particle CMD, within ±20% compared to reference CMD.

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Section: Introductionsupporting

confidence: 75%

Section: Considerations Regarding the Reference Cmdmentioning

confidence: 99%

Combining NSAM and CPC concentrations to determine airborne nanoparticle count median diameter: Application to various laboratory and workplace aerosols

Bau

Payet

Toussaint

et al. 2018

Journal of Occupational and Environmental Hygiene

View full text Add to dashboard Cite

show abstract

“…The Pegasor AQ Urban does not measure particles larger than 400 nm and hence it is essentially missing the significant particle size fractions contributing to mass concentrations. The underestimation of LDSA in >400 nm particle sizes is characteristic to diffusion charging-based instruments (Asbach et al 2009;Todea et al 2015). This is due to gradually decreasing charging efficiency resulting from repulsive forces between highly charged particles and ions.…”

Section: Relationship Of Ldsa To Other Air Quality Parametersmentioning

confidence: 99%

“…Formed ions are driven onto the surfaces of particles by diffusional forces, and a current signal can be measured by collecting the particles with a Faraday cup electrometer or by using so-called measurement of escaping current. This method enables measurement of ultrafine particles and, more specifically, the LDSA concentration with good accuracy (Todea et al 2015). Currently, several instruments and sensors (e.g.…”

Section: Introductionmentioning

confidence: 99%

Long-term sensor measurements of lung deposited surface area of particulate matter emitted from local vehicular and residential wood combustion sources

Kuula

Kuuluvainen

Niemi

et al. 2019

Aerosol Science and Technology

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“…Leskinen et al (2012) compared LDSA concentrations measured with NSAM and SMPS and found that for TiO 2 agglomerates and dust agglomerates and found that values from NSAM were higher than those of the SMPS. Todea et al (2015) compared the measured LDSA from Aerotrak and NSAM for monodisperse spheres and agglomerates with the calculated value based on number concentration from a Condensational Particle Counter (CPC) and knowledge of particle size. They found that for spherical particles the NSAM and Aerotrak data both generally agreed within ± 30% with the calculated value from the CPC in the size range of 20 to 346 nm.…”

Section: Introductionmentioning

confidence: 99%

Can We Trust Real Time Measurements of Lung Deposited Surface Area Concentrations in Dust from Powder Nanomaterials?

Levin

Witschger

Bau

et al. 2016

Aerosol Air Qual. Res.

Self Cite

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A comparison between various methods for real-time measurements of lung deposited surface area (LDSA) using spherical particles and powder dust with specific surface area ranging from 0.03 to 112 m 2 g -1 was conducted. LDSA concentrations measured directly using Nanoparticle Surface Area Monitor (NSAM) and Aerotrak and were compared to LDSA concentrations recalculated from size distribution measurements using Electrical Low Pressure Impactor (ELPI) and Fast Mobility Particle Sizer (FMPS). FMPS and ELPI measurements were also compared to dust surface area concentrations estimated from gravimetrical filter measurements and specific surface areas.Measurement of LDSA showed very good correlation in measurements of spherical particles (R 2 > 0.97, Ratio 1.0 to 1.04). High surface area nanomaterial powders showed a fairly reliable correlation between NSAM and Aerotrak (R 2 0.73-0.93) and a material-dependent offset in the ratios (1.04-2.8). However, the correlation and ratio were inconsistent for lower LDSA concentrations. Similar levels of correlation were observed for the NSAM and the FMPS for high surface area materials, but with the FMPS overestimating the LDSA concentration. The ELPI showed good correlation with NSAM data for high LDSA materials (R 2 0.87-0.93), but not for lower LDSA concentrations (R 2 0.50-0.72). Comparisons of respirable dust surface area from ELPI data correlated well (R 2 > 0.98) with that calculated from filter samples, but materials-specific exceptions were present.We conclude that there is currently insufficient reliability and comparability between methods in the measurement of LDSA concentrations. Further development is required to enable use of LDSA for reliable dose metric and regulatory enforcement of exposure.

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Accuracy of electrical aerosol sensors measuring lung deposited surface area concentrations

Cited by 51 publications

References 35 publications

Combining NSAM and CPC concentrations to determine airborne nanoparticle count median diameter: Application to various laboratory and workplace aerosols

Combining NSAM and CPC concentrations to determine airborne nanoparticle count median diameter: Application to various laboratory and workplace aerosols

Long-term sensor measurements of lung deposited surface area of particulate matter emitted from local vehicular and residential wood combustion sources

Can We Trust Real Time Measurements of Lung Deposited Surface Area Concentrations in Dust from Powder Nanomaterials?

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