Using a Modified Electrical Aerosol Detector To Predict Nanoparticle Exposures to Different Regions of the Respiratory Tract for Workers in a Carbon Black Manufacturing Industry

Abstract

The present study was set out to characterize nanoparticle exposures in three selected workplaces of the packaging, warehouse, and pelletizing in a carbon black manufacturing plant using a newly developed modified electrical aerosol detector (MEAD). For confirmation purposes, the MEAD results were compared with those simultaneously obtained from a nanoparticle surface area monitor (NSAM) and a scanning mobility particle sizer (SMPS). We found that workplace background nanoparticle concentrations were mainly coming from the outdoor environment. Size distributions of nanoparticles for the three selected process areas during the work hours were consistently in the form of bimodel. Unlike nanoparticles of the second mode (simply contributed by the process emissions), particles of the first mode could be also contributed by the forklift exhaust or fugitive emissions of heaters. The percents of nanoparticles deposited on the alveolar (A) region were much higher than the other two regions of the head airway (H), tracheobronchial (TB) for all selected workplaces in both number and surface area concentrations. However, significant differences were found in percents of nanoparticles deposited on each of the three regions while different exposure metrics were adopted. Both NSAM and MEAD obtained quite comparable results. No significant difference can be found between the results obtained from SMPS and MEAD after being normalized. Considering the MEAD is less expensive, less bulky, and easy to use, our results further support the suitability of using MEAD in the field for nanoparticle exposure assessments.

Correlation between airborne particle concentrations in seven industrial plants and estimated respiratory tract deposition by number, mass and elemental composition

“…In contrast, the total deposited particle number concentration (14,000 cm À 3 ) is about the same at both positions, although the number concentration of airborne particles is much greater at Laser cutting. Wang et al (2010) predicted the nanoparticle deposition in various regions of the respiratory tract for workers in a carbon black manufacturing plant using the UK national radiological protection board's LUDEP software at nose breathing and light exercise. The particle size distributions were bimodal (NMMD: 39 and 124 nm at one location, and NMMD: approximately 25 and 165 nm at two locations).…”

“…They found that the surface area concentration was correlated with ultrafine particle number concentration (r 2 = 0.36-0.6) and weakly correlated with respirable mass concentration (r 2 = 0.09-0.28). A study by Wang, Tsai, Chen, Chen, & Hsu (2010) predicted the nanoparticle exposure in three regions of the respiratory tract for workers in a carbon black manufacturing industry. The deposition efficiency of the particle surface area and number concentrations that deposit in the alveolar region was concluded to be much higher than for the head airways and tracheobronchial regions.…”

Worker exposure to ultrafine particles during carbon black treatment

“…[24] w badaniach przeprowadzonych podczas pakowania, magazynowania i granulacji sadzy technicznej wykonali analizę stężenia liczbowego i powierzchniowego cząstek z użyciem następujących urzą-dzeń -MEAD (modified electrical aerosol detector) i NSAM (nanoparticle surface area monitor). Autorzy Godzina / Hour cząstki / particle 10-1 000 nm frakcja PM 1 / fraction PM 1 cytowanego badania uzyskali następujące wyniki po…”

Response to “Dr. Luca Giannini’s Letter to the Editor”

“…The particles in the nanoscale size range emission may be attributed to the forklift activity. Similarly, Wang et al (2010) demonstrated that the CB-NPs size distributions for packaging, warehouse, and pelletizing area in CB manufacturing plant exposure were consistently in the form of bimodal. The first mode (count median diameter, 24.2−39.2 nm) could be contributed not only by the process emissions but also by the forklift exhaust or fugitive emissions of heaters, especially in the warehouse and pelletizing area.…”

“…The second mode (count median diameter, 124−166 nm) was mainly from the CB-NPs emissions from the process areas. Wang et al (2010) also emphasized that CB, forklift exhaust, and heater fugitive are carbon-containing materials; therefore, it is very difficult, if not impossible, to measure each individual concentration of these three pollutants. Even so, based on the very conservative assumptions in our study, we adopted the experimental data (Kuhlbusch et al 2004) to assess the potential exposure risk in CB plants due to workers who may be exposed to part of CB-NPs in the bag filling areas in the CB plants.…”