Type of Document	Master's Thesis
Author	Yeganeh Talab, Behnoush
Author's Email Address	behnoush@vt.edu
URN	etd-03202007-124201
Title	Airborne Nanoparticles: Generation, Characterization, and Occupational Exposure
Degree	Master of Science
Department	Environmental Engineering
Advisory Committee	Advisor Name Title Marr, Linsey C. Committee Chair Love, Nancy C. Committee Member Vikesland, Peter J. Committee Member
Keywords	workplace exposure particle control nanoparticles nanomaterials C60 fullerene occupational health
Date of Defense	2007-03-14
Availability	restricted
Abstract Despite the rapid growth in nanotechnology, very little is known about the unintended health or environmental effects of manufactured nanomaterials. The development of nanotechnology risk assessments and regulations requires quantitative information on the potential for exposure to nanomaterials. In addition, to facilitate life-cycle assessments and inhalation toxicology studies, robust methods are needed to generate aerosolized engineered nanoparticles. We conducted a set of field studies to measure the fine particle mass concentrations (PM2.5) as well as nanoparticle number concentrations and size distributions in two nanomaterial manufacturing facilities. Measurements were performed near the reactor, in the breathing zone, and at a background site. Increases in PM2.5 and particle number concentrations were associated with physical handling of nanomaterials. The highest PM2.5 concentration observed was 2700 ug m-3 during sweeping of the reactor in the commercial plant. In most cases, an increase in the number of sub-100 nm particles accounted for the increase in total number concentrations. The results of this research can be used to develop guidelines for workplace regulations to minimize workers' exposure to nanoparticles. Furthermore, we used an atomizer to aerosolize C60 aggregates from a fullerene-water suspension. Measurement of particle size distributions and number concentrations showed that increasing the initial fullerene concentration resulted in increased number of aerosolized particles, while the average size of particles remained relatively constant. To return the aerosolized fullerenes into water, we passed the aerosol sample through an impinger. Reducing the flow rate through the impinger resulted in an increase in the collection efficiency of airborne nanoparticles.
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