Dr. Rao has a PhD in Environmental Health from the Harvard University School of Public Health, and has been working at NIOSH on the assessment of microbial exposures for epidemiologic studies of indoor workers.  Dr. Rao will talk about the limitations of the existing methods of assessing microorganisms in air and dust, ideas for new methods and their advantages, and preliminary results from the use of selected new methods and new applications of existing methods by NIOSH.