Urban Air

Responding to Air Toxic Concerns by Building Research Capacity for Understanding Sustainable Urban Atmospheres


In response to public concern about toxic metals air pollution in Portland neighborhoods, the Institute for Sustainable Solutions (ISS) at Portland State University (PSU), in partnership with the City of Portland and Multnomah County will provide approximately $125,000 plus staff time for advanced chemical analysis equipment, supplies, and services to conduct further research on the subject. Over the course of two years, this research, led by PSU Professor of Environmental Science and Management Dr. Linda George will provide in-depth testing of six sites identified by prior research and in discussion with public health agencies and neighborhood organizations. This project will provide timely research for public health and other officials to consider whether or how to adjust policies, regulations, and/or monitoring activities. ISS provided financial resources and staff time to catalyze the idea and broker community-university partnerships to successfully launch this project, put up just over $62,500 in funding, and secured matching contributions totaling $62,500 from partners at the City of Portland and Multnomah County to advance this timely research.

Read the press release: PSU, City of Portland and Multnomah County partner on toxic air research

Introduction: Metals Pollution in Portland Neighborhoods and the Issue of Urban Air Quality

In February 2016, news broke in Portland about high levels of arsenic and cadmium in the Southeast Portland air, prompting calls for more oversight and a swift reaction to what lawmakers have identified as “a public health emergency.” The still unfolding situation stemmed from a 2013 U.S. Forest Service (USFS) study of moss collected in Portland neighborhoods and analyzed for metals pollution. (PSU students in an Urban Ecology class worked with partners at the Forest Service to conduct follow-on moss studies in Southeast and North Portland.) Information about the pollution was passed on to the Oregon Department of Environmental Quality (DEQ) by USFS in May 2015, but not made public until February 2016, prompting not only fear about the effects of metals pollution, but also public distrust of the enforcement and efficacy of clean air laws. PSU’s expertise and history of studying urban air quality and related issues, including the role of urban trees and the effects of heat islands, positions the University to assist with timely and important research about the quality of Portland’s neighborhood air. With the assistance of the ISS, PSU is well equipped to assemble an interdisciplinary team with the expertise to collect and analyze data that will be useful to policy makers.  


Recent developments in characterizing pollutants, their sources, and spatial implications on human health offer promising opportunities for reducing harmful impacts. In fact, the availability of a rapid, sensitive, and non-destructive method for assessing metals in the environment is timely. This method, called X-Ray fluorescence analysis (XRF), will enable a cost-effective and rapid turnaround research agenda related to the emission and fate of metals from a variety of anthropogenic sources. 

The USFS moss maps provide very useful information for exploring metals deposition. Further work is needed in exploring the variables—topography, weather patterns and the like—involved in near source spatial distribution of ambient metals levels and metals deposition. This project seeks to assess atmospheric conditions using an XRF. The first aim of this research is related to air emissions, but the instrument can also be useful for investigating metals in water, consumer goods (e.g., toys and plastics), solid wastes, etc.  To that end, our research agenda has two primary objectives:

  1. Assessing the relationships between emissions and the metals levels in air, soil, indoor surfaces, and moss as related to the chemical element, meteorology, and topography, etc.; and
  2. Investigating novel approaches for rapid assessment of metals in the environment using XRF.

The research will meet the rigorous standards of scientific research; it is not a substitute for the monitoring done by the Department of Environmental Quality, which has strict protocols to follow in order to meet legal standards. However, the second objective is motivated by the desire to provide regulatory agencies and other agencies a rapid assessment method for metals that could be used to trigger regulatory monitoring or inform policy.

Assessment of Spatial Variability of Metals in the Environment (Portland Tri-County Area)

This investigation will involve the following activities for at least six sites of about one square-mile each over the course of two years in the Portland metro area to be determined in consultation with the City of Portland, Multnomah County, Oregon Department of Environmental Quality, Oregon Health Authority, U.S. Forest Service, and community groups.  Considerations for site selection would include variation in source categories, topography, canopy structure, proximity to residences, types of metals expected, etc. 

Research activities include:

  1. Sampling of air, soil, moss, and, potentially, indoor surfaces for metals. Roughly 100 multimedia samples would be collected for each site over two months;
  2. Conducting  modeling to estimate emission levels; and
  3. A statistical analysis of the variation of pollutants to explore the potential of multiple source categories impacting a particular site.

Outcomes: Maps and source analyses for at least six sites over two years. 

Investigating Novel Approaches for Rapid Assessment of Metals in the Environment Using XRF

While XRF is a relatively old technology, its sensitivity has greatly improved in recent years, and is extremely well suited for research in air toxic metals. This project will also make use of student research as well as citizen scientist interest to collect samples, which would complement the technical contributions of the project in developing monitoring techniques to rapidly assess the environment for toxics. This work will explore the potential of XRF analysis of moss, leaves, and soil samples; relate them to ambient levels; and use a spatial platform to explore a broader range of potential receptors.

Outcomes: Analysis of various assessment techniques, development of new techniques, and potential for publications and proposals.   

  • July 2016: Identify vendors who can provide XRF equipment. 
  • August 2016: Purchase and installation of XRF.
  • September 2016: Calibration and initial testing of XRF; identification of sampling locations.
  • October – April 2017: First year field campaign for collection of samples; analysis of field samples and interpretation of results; preliminary development of reports. 
  • May – June 2017: Report development, review, and presentations.
  • July – March 2018: Second year field campaign for collection of samples; analysis of field samples and interpretation of results. 
  • April – June 2018: Report development, review, and presentations.
  • July 2018: Final reports delivered. 


ISS will provide in-kind staff time and more than $62,500 of funding toward this project, which will be lead by Linda George, an accomplished atmospheric chemist and PSU professor of environmental science and management and a Faculty Fellow of ISS. Dr. George’s time is considered in-kind as well. ISS has secured a combined contribution of $62,500 from partners at the City of Portland and Multnomah County. 

Project Partners

Linda George

Dr. George has been studying air quality for nearly 30 years. Her primary research interests include monitoring and modeling of urban air pollutants as they relate to urban infrastructure, such as transportation systems, land use, and urban form. She has served in scientific review capacities as a program director for the National Science Foundation (Division of Atmospheric and Geospace Sciences), as well as an associate editor for the journal "Science in the Total Environment." She is currently serving on OR SB 202 Taskforce on Independent Science Review. Her research has been funded with more than $6 million from the National Science Foundation, the U.S. EPA, USAID, and several private foundations. 

City of Portland

In April, the City of Portland under the leadership of Mayor Charlie Hales, Commissioner Steve Novick and his colleagues on the Portland City Council, approved a special appropriation for $31,250 to fund the toxic metals research. 

Multnomah County 

In April, Multnomah County Chair Deborah Kafoury, working closely with John Wasiutynski, director of the Multnomah County Office of Sustainability, made the decision to include $31,250 to support the research in the Chair’s portion of the Multnomah County Budget. 

Neighbors for Clean Air

Neighbors for Clean Air’s mission is to create a healthier Oregon by reducing air pollution, especially emissions of air toxics. To accomplish this goal, NCA works to educate and empower communities so that they can advocate for reducing air pollution. Neighbors for Clean Air is a longtime collaborator with PSU and Dr. George on air quality research and related projects. 
Institute for Sustainable Solutions
The Institute for Sustainable Solutions (ISS) at PSU, fosters innovative cross-disciplinary research, critical skill-building curriculum, and effective community engagement to solve complex challenges in Portland and beyond. ISS is supported by a 10-year, $25M challenge grant awarded to the University in 2009 by the James F. and Marion L. Miller Foundation, and uses these funds to leverage additional resources that can support the PSU student experience, community engagement, and faculty research and excellence.