Dr. Mullen holds an M.S. (2006) and Ph.D. (2011) in Civil & Environmental Engineering from the University of California, Berkeley. She holds a B.S. (2005) in Architectural Engineering from the University of Texas at Austin. Her graduate level research was focused on furthering understanding of human exposure to ultrafine particle concentrations in indoor environments. As an undergraduate student, she assisted with research investigating the clean air delivery rate and ozone emission rate of ion-generating air cleaners.