Entrainment and Detection of Engineered Nanoparticles

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CBET-1236909The proposed research addresses the need to understand workplace exposures to engineered nanoparticlesin two ways: (i) by investigating fundamental mechanisms by which engineered nanoparticlesmay become airborne; and (ii) by developing aerosol instruments suitable for routine workplace andpersonal monitoring of nanoparticles in the 1-500 nm size range with the ability to follow transientthat may be responsible for most exposure from well-designed nanoparticle synthesis systems.Controlled laboratory experiments will also be conducted to develop a fundamental understandingof mechanisms for nanoparticle release to the air, beginning with studies of the aerodynamicentrainment from nanoparticle-coated surfaces. The long-standing need for suitable instrumentsfor monitoring workplace exposures will be addressed by creating a small, simple, and low costnanoparticle opposed migration aerosol detector (NOMAD) that will enable exposure assessmentwith sufficient resolution to estimate lung deposition patterns. The NOMAD performance will becompared with conventional approaches to exposure monitoring in nanotechnology laboratories, andprovide personal exposure data that is not presently possible.Intellectual merit: The proposed research will survey sources of airborne nanoparticles usingsize resolved instruments with better time response, and broader coverage of the potential sizerange than employed in previous studies, thereby enabling detection of transient release events, andfacilitating identification of nanoparticle sources. Subsequent controlled laboratory experiments willquantify the forces required to entrain nanoparticles from different kinds of surface deposits, and theextent of agglomeration the airborne nanoparticles that result, thereby laying the groundwork fora fundamental understanding of potential exposure mechanisms. The new instruments will enablehealth effects studies that are clearly needed to understand the risks of nanotechnology, but arenot presently possible due to the cost and complexity of present instruments. With these tools,continuous exposure data will become a valuable tool in both health effect research and in workerprotection. They will further enable studies of exposures to nanoparticles in the use of consumernanotechnology products, and from conventional pollution sources.Broader impacts: The proposed research will provide new insights into incidental processesthat contribute to the release of engineered nanoparticles into workplace air, and the risks associatedwith such releases. The new airborne nanoparticle detectors will enable researchers and industry tomonitor nanoparticle exposures with rigor that is not now possible. Moreover, these new detectorsshould become the enabling technology for health effects studies that are clearly needed, but notpresently possible.Undergraduates will have the opportunity to become involved in the project through Caltech?sSummer Undergraduate Research Fellowship (SURF). In addition, the Flagan laboratory will recruitparticipants from the Minority Undergraduate Research Fellowship (MURF) program as it has in4 of the last 6 years. We will work with Caltech?s outreach program to invite local area students tolectures and visits to our laboratory, as well as talk to the students in their schools. Students fromlocal high schools, particularly those near freeways, will be recruited to undertake science projectsinvolving measurements of nanoparticles in their home or school environments.As he has done for 10 years, the PI will continue to co-mentor a First Robotics team at RamonaConvent Secondary School, a girls high school in Alhambra, CA that has 60% minority enrollment.This has proven to be a most effective mechanism in stimulating interest in pursuing STEM studiesin college by showing the students that engineering is fun.