Toxicological Evaluation of Realistic Emission Source Aerosols (TERESA): Introduction and overview

Abstract

Determining the health impacts of sources and components of fine particulate matter (PM_2.5) is an important scientific goal. PM_2.5 is a complex mixture of inorganic and organic constituents that are likely to differ in their potential to cause adverse health outcomes. The Toxicological Evaluation of Realistic Emissions of Source Aerosols (TERESA) study focused on two PM sources—coal-fired power plants and mobile sources—and sought to investigate the toxicological effects of exposure to emissions from these sources. The set of papers published here document the power plant experiments. TERESA attempted to delineate health effects of primary particles, secondary (aged) particles, and mixtures of these with common atmospheric constituents. TERESA involved withdrawal of emissions from the stacks of three coal-fired power plants in the United States. The emissions were aged and atmospherically transformed in a mobile laboratory simulating downwind power plant plume processing. Toxicological evaluations were carried out in laboratory rats exposed to different emission scenarios with extensive exposure characterization. The approach employed in TERESA was ambitious and innovative. Technical challenges included the development of stack sampling technology that prevented condensation of water vapor from the power plant exhaust during sampling and transfer, while minimizing losses of primary particles; development and optimization of a photochemical chamber to provide an aged aerosol for animal exposures; development and evaluation of a denuder system to remove excess gaseous components; and development of a mobile toxicology laboratory. This paper provides an overview of the conceptual framework, design, and methods employed in the study.

Keywords::

• Coal power plant
• emissions
• fine particulate matter
• secondary particles
• toxicology

Acknowledgments

We gratefully acknowledge technical assistance from Dr. Mike Wolfson, Dr. Joy Lawrence, and Dr. Tarun Gupta.

Declaration of interest

This project was supported by the Electric Power Research Institute (Contract EP-P10983/C5530/56546), the U.S. Environmental Protection Agency Center for Particle Health Effects at the Harvard School of Public Health (grant R827353), and the Harvard NIEHS Center for Environmental Health (grant ES00002). This work was also prepared with the support of the U.S. Department of Energy under award DE-FC26-03NT41902, and the Wisconsin Focus on Energy Environmental Research Program. However, any opinions, findings, conclusions, or recommendations expressed herein are those of the authors, and do not necessarily reflect the views of the U.S. EPA or the DOE. The Electric Power Research Institute (EPRI) employs Annette C. Rohr.