Guest Researchers

Bill Nazaroff

Bill Nazaroff

Ph.D. , Professor

International Centre for Indoor Environment and Energy
Technical University of Denmark, Building 402
DK-2800 Lyngby, Denmark

At the Centre from September 2006 to December 2006

Phone:
Fax: +45 45 93 21 66
Email:

Department of Civil and Environmental Engineering
University of California
Berkeley, California

Research interests

Professor Nazaroff's research group aims to understand the physical and chemical processes that govern air pollutant concentrations and fates. The goal is to develop the information needed to assess and control human health effects from air pollutant exposures. Dr. Nazaroff's research is conducted through laboratory-scale experiments plus numerical and analytical modeling. The following topics are being addressed: (a) interactions between pollutants and surface materials; (b) air movement and pollutant dispersion in indoor environments; and (c) characterization and control of air pollutant exposures. Dr. Nazaroff's students work closely with research staff of the Indoor Environment Department at Lawrence Berkeley National Laboratory.

Air pollutant interactions with surfaces
The interactions of pollutants with surfaces is of central importance in air quality engineering. Such interactions can be beneficial by reducing airborne concentrations and human exposures to pollutants. These interactions can also be detrimental, for example, by causing damage to sensitive objects kept indoors. Experiments, analysis, and mathematical modeling are being performed to better understand the mass-transport aspects of pollutant deposition to indoor surfaces and the kinetics of surface interactions. Current emphases include (a) understanding the interaction of semivolatile organic compounds with indoor surfaces; (b) characterizing the interaction of ozone with materials such as carpeting; and (c) investigating the deposition of particles on building surfaces, including ventilation-system ducts and cracks in the building envelope.

Indoor air movement and pollutant dispersion
The issue of dispersion and transport arises because many indoor air pollutants are released from localized sources. Predicting and efficiently controlling exposures to these pollutants requires information on airflow and on the rate of mixing in indoor air. Many indoor air quality investigations are based on the approximation that indoor air is well mixed, so that pollutant concentrations measured at one point represent concentrations at all points within a room or a building. We have been following three lines of investigation aimed at developing tools needed to relax the assumption of uniform mixing when appropriate: (a) numerical modeling of pollutant transport and dispersion using techniques of computational fluid dynamics; (b) studies of transport and mixing using controlled release of a tracer gas followed by sampling air as a function of time at a network of indoor points; and (c) development of optical remote sensing techniques coupled with computed tomography for measuring the spatial distribution of tracer gas in a plane.

Characterizing and controlling air pollutant exposures
Many air quality problems arise because of direct emissions of a contaminant into indoor air. Understanding the nature of these emissions is an important step in the development of effective control measures. Studies of the resulting concentrations, exposures, and potential effectiveness of engineering control measures are also of interest. We recently conducted modeling investigations on exposure air toxics from environmental tobacco smoke. New work is being initiated to explore the factors that govern human exposure to particulate matter of outdoor origin.