News & Events
Exposure and Hazard of Engineered Nanomaterials in Terrestrial Systems
Speaker(s): Prof. Patricia A. Holden, Bren School of Environmental Science & Management, University of California, Santa Barbara.
When: 15 September 2016 (11:00am - 12:00pm)
Where: SBS Classroom 5 (Level 1)
Type: Seminars


At the University of California Center for Environmental Implications of Nanotechnology (UC CEIN), we develop and apply approaches to assess exposure to and hazards of engineered nanomaterials (NMs) to terrestrial ecosystems. NM release scenarios and fate modeling establish realistic exposure regimes that influence conditions of tiered hazard assessment. Base food web receptors include heterotrophic and N2-fixing bacteria, and the primary producers, photosynthetic plants. Biological trophic transfer and the potential for biomagnification of bioaccumulated NMs initiate with protozoan and insect predators, respectively, and are studied as NM biological transport vehicles. In parallel bacterial and plant population growth studies, the objective is to define dose-response and bioaccumulation patterns for bioavailable NMs. Single-celled microbial studies are miniaturized for high throughput (HT) research, while microbial community studies, composition and diversity shifts allow for assessing NM bioavailability in soil. Mathematical models of receptor growth and multi-receptor feedbacks are populated by findings regarding damage mechanisms and magnitudes. The approaches are illustrated, using results from researching hazards at cellular, population, community, and ecosystem scales for metal (Ag, and Cu), metal oxide (TiO2, ZnO, CeO2), quantum dot (CdSe), and carbonaceous (MWCNT, carbon black, graphene) NMs.

Speaker's Bio

Dr Patricia (Trish) A. Holden is a Professor in the Bren School of Environmental Science & Management at the University of California, Santa Barbara, Director of the UCSB Natural Reserve System, and a departmental affiliate in Mechanical Engineering, Ecology Evolution and Marine Science, Earth Science, and the Interdisciplinary Graduate Program in Marine Science. She received her Ph.D. in Soil Microbiology (1995) and M. Eng. from U.C. Berkeley, and Civil & Environmental Engineering M.S. and B.S. degrees from Purdue University and the University of Tennessee, respectively. She has served as a panelist for numerous NSF programs and for NIEHS, was an Associate Editor for the Soil Science Society of America Journal (2009-12), and since 2003 has served as a member of the State of California Clean Beach Task Force. She has published over 110 articles in peer-reviewed journals, and was a co-author of The California Microbial Source Identification Manual (2013). Prior awards include a UC Graduate Mentorship, selection as a Switzer Environmental Fellow, UCSB Faculty Career Development Award, Excellence in Teaching (Bren School), Fellowship in the Association of Pacific Rim Universities, and Excellence in Reviewing (2010, ES&T).