Workplace exposure. Measurement of exposure by inhalation of nano-objects and their aggregates and agglomerates. Metrics to be used such as number concentration, surface area concentration and mass concentration

2018 ◽  
Keyword(s):  
Surface Area ◽  
Mass Concentration ◽  
Number Concentration ◽  
Exposure Measurement ◽  
Workplace Exposure ◽  
Surface Area Concentration ◽  
Concentration Surface

Occupational Exposure Assessment of CaCO3 Nanoparticles Using a Multi-Metrics Approach

2014 ◽  
Vol 886 ◽  
pp. 271-274
Author(s):  
Peng Zhao ◽  
Shi Chuan Tang ◽  
Jie Min Liu ◽  
Yu Qian Wang ◽  
Zai Yu
Keyword(s):  
Occupational Exposure ◽  
Linear Relationship ◽  
Surface Area ◽  
Mass Concentration ◽  
Number Concentration ◽  
Manufacturing Plant ◽  
Occupational Exposure Assessment ◽  
Exposure Metrics ◽  
Concentration Surface ◽  
Mass Concentrations

The possible exposure to nanoparticles (NPs) were investigated in a nanosized CaCO3 manufacturing plant using a multi-metrics approach: mass concentration, number concentration, surface area (SA) concentration. The mass concentrations of particle ranged from 0.1497 to 3.2647 mg/m3 for area samplings. The SA concentrations of particles ranged from 149 to 3007μm2/cm3. The number concentrations of particle ranged from 3.56×1010 to 4.07×1011 pt/m3. The particle SA concentrations exhibited the same trend as the number concentrations, and the variability of these two exposure metrics between the eight areas was greater than the mass concentration. This indicates that occupational exposure assessments using mass concentration of NPs maybe underestimate their toxicity. The number concentrations had better linear relationship with SA concentrations versus mass concentrations (coefficients of correlation, R=0.84 and 0.75, respectively), and the mass concentrations had weakest linear relationship with SA concentrations (R=0.61). The surface area and number metrics may be a more suitable metric for NPs occupational exposure.

scholarly journals Profiles of cloud condensation nuclei, dust mass concentration, and ice-nucleating-particle-relevant aerosol properties in the Saharan Air Layer over Barbados from polarization lidar and airborne in situ measurements

2019 ◽  
Vol 19 (22) ◽  
pp. 13773-13788 ◽  
Author(s):  
Moritz Haarig ◽  
Adrian Walser ◽  
Albert Ansmann ◽  
Maximilian Dollner ◽  
Dietrich Althausen ◽  
...  
Keyword(s):  
Surface Area ◽  
Mass Concentration ◽  
Cloud Condensation Nuclei ◽  
Number Concentration ◽  
Condensation Nuclei ◽  
Dust Layer ◽  
Saharan Air Layer ◽  
Lidar Observations ◽  
Aerosol Properties

Abstract. The present study aims to evaluate lidar retrievals of cloud-relevant aerosol properties by using polarization lidar and coincident airborne in situ measurements in the Saharan Air Layer (SAL) over the Barbados region. Vertical profiles of the number concentration of cloud condensation nuclei (CCN), large particles (diameter d>500 nm), surface area, mass, and ice-nucleating particle (INP) concentration are derived from the lidar measurements and compared with CCN concentrations and the INP-relevant aerosol properties measured in situ with aircraft. The measurements were performed in the framework of the Saharan Aerosol Long-range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE) in summer 2013. The CCN number concentrations derived from lidar observations were up to a factor of 2 higher than the ones measured in situ aboard the research aircraft Falcon. Possible reasons for the difference are discussed. The number concentration of particles with a dry radius of more than 250 nm and the surface-area concentration obtained from the lidar observations and used as input for the INP parameterizations agreed well (<30 %–50 % deviation) with the aircraft measurements. In a pronounced lofted dust layer during summer (10 July 2013), the lidar retrieval yielded 100–300 CCN per cubic centimeter at 0.2 % water supersaturation and 10–200 INPs per liter at −25 ∘C. Excellent agreement was also obtained in the comparison of mass concentration profiles. During the SALTRACE winter campaign (March 2014), the dust layer from Africa was mixed with smoke particles which dominated the CCN number concentration. This example highlights the unique lidar potential to separate smoke and dust contributions to the CCN reservoir and thus to identify the sensitive role of smoke in trade wind cumuli developments over the tropical Atlantic during the winter season.

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