Aerosols and Air Quality

Washington University has had a tradition of research in the area of aerosols and air quality since the 1960s (Macias, White, Husar), and this remains an area of topical priority for the St. Louis region. With the rebirth of the Environmental Engineering Science Program in 2000, additional faculty (Biswas, Chen, Falke) were hired to comple-ment the efforts of the existing faculty (Husar, Axelbaum, Turner). With interactions with colleagues in the School of Medicine (Evanoff, Stanley) and in the School of Law (Lipeles), there is significant strength in this area. Aerosol issues are of importance in the environment in outer space, as exploration will take humans to build colonies on distant planets and terrestrial bodies (Stadermann, Chen, Biswas).

Aerosol science and engineering is now referred to as an enabling science and has application in a number of areas in addition to the environment. Progress in many technical areas of importance to government and industry depends on aerosol science and technology which, for this reason, it is now referred to as an enabling technology. An important theme is the demand for ever faster acquisition of size distribution and particle chemical composition data. Another is dealing with aggregates, the natural state of very small solid particles. We are still wrestling with the question "where does the atmospheric aerosol come from?" (Turner) This question is of central importance to our daily life, industrial development, and climate change. Also of significance is the role of aerosol science and technology to the field of nanotechnology. Nanoparticle aerosol science and technology is the backbone for nanotechnology, as it allows for the synthesis of nanomaterials with tailored sizes and compositions (Axelbaum, Biswas, Chen). There are many applications of nanomaterials-and a new discipline of environmental nanotechnology is mushrooming. This allows the use of these materials to minimize environmental damage and to develop new technologies (such as energy technologies) that are benign. The use of catalysts is another example, and Washington University is a partner in the Center for Environmentally Beneficial Catalysis, an NSF-funded Engineering Research Center (Dudukovic, associate director). At the same time, prior to wide-scale adoption of nanotechnology, one must ensure that it is a benign technology. Research is ongoing at understanding the fundamental biological effects of nano-particles, which will allow understanding the negative impacts (to human health) and the design of processes for delivery of drugs to treat diseases (Biswas, Chen, Lanza, Stanley, Wickline). Washington University researchers (Sureshkumar, Khomami) have expertise in flow modeling and additives rheology that can contribute to studying phase behavior of lung surfactants (phoshplipids) and nanoparticles at fluid-fluid interfaces. Bioaerosol research is underway to evaluate capture and inactivation technologies (Biswas, Angenent).

Aerosol-related problems have attracted talented scientists of many backgrounds (various Nobel laureates CTR Wilson, Einstein, Millikan, and recently Richard Smalley). Much of modern aerosol science and technology is based on the work of scientists who did not consider themselves aerosol specialists or experts. This has now changed-and aerosol scientists are contributing in a very big way. It is anticipated that aerosol scientists are going to play a major role in the advancement of science in many disciplines, specifically those related to air quality, energy, and other important environmental issues facing us today.

Key Issues:
  • Atmospheric air quality. There is evidence that fine particles in the atmosphere may have enhanced deleterious health effects. Studies need to continue to unravel the source of the ultrafine particles, and understand their health impacts.
  • Indoor air quality. Individuals spend significant portions of their time indoors. Furthermore, with homeland security issues, protecting indoor air quality is of prime importance, especially in sensitive buildings and public places (malls, transportation systems). Residential, office, and occupational environments are of interest. Work has to proceed on real-time detection and control.
  • Combustion systems. Energy needs will be supplied by combustion processes for the next 30 years. These processes have to be environmentally benign to ensure minimal impact on the environment. Technology has to be used to the fullest extent to control the release of pollutants.
  • Global climatology. The role of aerosols in global climate issues is significant, and a better understanding has to be developed to eventually control climate change that is being observed.
  • Global air quality issues. Measurements provided by satellites are providing large data sets that need to be understood to elucidate global air quality impacts. Satellite data need to be harvested and integrated with ground-based station data to make them more robust and useful.
  • Analysis of air quality data over various spatial and temporal scales will also help improve our understanding of causal factors and their impact. The use of geospatial information sciences and technology, including GIS-based approaches, should enhance our ability to better share and interpret the data; models can be used to better explain trends.
  • Web information systems. Web technologies are revolutionizing the way air quality data are shared and how government agencies, universities, and industry collaborate in collecting, analyzing, and applying environmental information.
  • Near real time analysis as measurement instrumentation and information technology advance, near real time assessment of the state of the environmental are becoming feasible. Research and development are needed to support real-time air quality analysis and modeling systems for applications such as homeland security.
  • Particle control technology. More developments are needed to protect individuals in workplaces, homes, and the outdoors. As space exploration proceeds, novel methods need to be developed for protection of pioneers who reach out to conquer space.
  • Nanoparticle aerosol science and technology-a mushrooming area that can contribute to advancement of basic science (understanding the unique properties of materials at the nanoscale), applications in medicine (nanomedicine), environmental remediation, and control. Understanding of fundamental phenomena such as nuclea-tion in a variety of systems is critical to many disciplines.
  • Particle Instrumentation. Developments in instrumentation are critical to make advances in all the above areas. Instruments need to be miniaturized for personal sampling and made robust enough for use in industrial processes.

Interactions:

The Center for Aerosols and Air Quality will have members from the Schools of Engineering, Arts & Sciences, Law, and Medicine. Wonderful opportunities exist for synergies with the Center for Energy. Global climate issues and the hydrologic cycle, and transfer of pollutants from the atmosphere to water bodies (such as mercury) have a direct tie to the Center for Sustainable Rivers. Linkages to the Center for Environmental Health are several-fold-with both ambient air quality and indoor air quality studies.

Washington University Strengths:

This has been elucidated in the introductory statements. The School of Engineering & Applied Sciences has a world-renowned aerosol program in place. There are twenty graduate students working with four faculty members in the Environmental Engineering Science Program. Significant strengths are in understanding particle formation and growth, instrumentation and measurement, ambient air quality, satellite mapping, and geospatial analysis. Ties to researchers with expertise in the biological and medical sciences is strong-toxicologists at the University of Rochester, and University of Cincinnati; epidemiologists at Saint Louis University, and the University of Cincinnati, and Harvard University; and medical scientists at Washington University and elsewhere. There is a strong relationship with corporate partners, national laboratories, and international partners-thus providing a network of players.

Key Players:

Engineering (Angenent, Axelbaum, Biswas, Chen, Dudukovic, Husar, Falke, Khomami, Sureshkumar, Turner), EPSc (Arvidson, Fegley), Medicine (Evanoff, Lanza, Stanley, Sweet, Wickline), Arts & Sciences (Bender, Castro, Macias, Smith, Stadermann), Architecture (Donnelly), and Law (Lipeles).

Areas that need further development:

  • Researchers in the areas of global climatology and atmospheric sciences.
  • Improved interactions with colleagues in the biological sciences.
  • Coordinated efforts between experimental and computational researchers.
  • Organize Workshop to set National Agenda.
  • Hire faculty in selected areas-global climate, atmospheric sciences, computational modeling, pulmonary aerobiology.
  • Improve outreach efforts.
  • Create and promote a network of corporate and international university partners.

Summary:

The elements for the Center for Aerosols and Air Quality are in place at Washington University. Significant additional potential should be realized by promoting research and educational collaborations with the Center for Energy Research.