Air Quality Research
Environmental Impacts of Nanotechnology
Faculty Member: Dr. Linsey Marr, Dr. Amy Pruden, Dr. Peter Vikesland
Nanotechnology brings the promise of improved medical imaging, thin display screens, and clean energy. Although the growth of the nanotechnology industry has been breathtakingly rapid, very little is known about the environmental effects of manufactured nanomaterials. Regarding nanoparticles in the atmosphere, we are tackling several projects: (1) exposure to nanomaterials released from consumer products, (2) oxidation of fullerenes in the atmosphere by ozone, (3) transformation and fate of nanomaterials during incineration, and (4) emissions and transport of naturally occurring and incidental nanoparticles such as soot. Our nanoparticle research facilities include an aerosol generator, Teflon smog chamber, scanning mobility particle sizer to measure submicron particle size distributions, aerosol photometer to measure larger particle size distributions, diffusion charger to measure particle surface area, aethalometer to measure black carbon, and photoionization aerosol sensor to measure particulate polycyclic aromatic hydrocarbons.
Air Pollutant Emissions
Faculty Member: Dr. Linsey Marr
Outdoor air pollution causes 700,000 deaths per year; and in the absence of new approaches to the problem, this number is expected to rise to 8 million per year over the next two decades. Gaseous and particulate pollutants in the atmosphere play critical roles in public health, global climate change, and visibility. Although the link between air pollution and its effects is firmly established, air quality science and management remain stymied by highly uncertain estimates of the emissions that cause air pollution. Therefore, we are interested in developing improved methods for quantifying air pollutant emissions and applying these to generate new estimates of emissions.
We have developed a mobile Flux Laboratory for the Atmospheric Measurement of Emissions (FLAME) to directly measure neighborhood-scale emissions of carbon dioxide, particles, and nitrogen oxides. The FLAME has been used in field campaigns in a small rural town dominated by coal transport (Worthington, KY), a city whose air quality is considered to be “nonattainment” with national ozone and particulate matter standards (Norfolk, VA), an international border city (Tijuana, Mexico), and a regional airport (Roanoke, VA).
Characterizing Sources of Volatile Compounds in the Indoor Environment
Faculty Member: Dr. John Little
Building materials are one of the primary indoor sources of volatile compounds, contributing to poor indoor air quality. We are developing fundamental models that predict emissions from several generic types of building material, and testing rapid procedures to measure model parameters. Our methods include formulation of mechanistic models, development of solutions using analytical techniques, dynamic microbalance experiments for rapid determine of diffusion and partition coefficients, and limited large-scale chamber tests to provide data for model validation.
Assessing Human Inhalation Exposure to Air/Water Partitioning of Odorous Compounds
Faculty Member: Dr. Andrea Dietrich
Worldwide, consumers complain about their drinking water is it smells bad, and may not drink the water even if it meets health standards. Insuring that water is palatable in taste and odor is important for human health. People are exposed to aqueous contaminants not only through drinking and bathing, but also by breathing dissolved aqueous compounds that partition into the air. Henry’s Law is the main principle used to predict air-water partitioning. If the compounds that volatilize into the air are odorous, people will know that they are exposed to the chemical as long as the chemical is above the odor threshold concentration of that person. We are investigating the chemical/physical factors that affect transfer of water contaminants to the air and also evaluating the factors that contribute to human detection of odorous compounds. One aspect of this work is training human panelists to smell and rate their drinking water.