Argonne part of national team studying Mexico City air

ARGONNE, Ill. (Feb. 28, 2006) – A new round of environmental data collection begins today in the Mexico City metropolitan area, the world's second largest megacity, to help understand air quality and climate in urban areas. Researchers from the U.S. Department of Energy's Argonne National Laboratory will join researchers from the Molina Center for Energy and the Environment, the National Center for Atmospheric Research, and the National Aeronautics and Space Administration (NASA) in collecting and examining the environmental data.

The effort is part of MILAGRO, the Megacity Initiative: Local and Global Research Observations research program, funded by the National Science Foundation, NASA and the Department of Energy's Office of Science. Jeff Gaffney, environmental scientist at Argonne, is in Mexico City to lead one of the four arms of the overall research project. Data collection will be done throughout the month of March.

Large urban areas are known to be significant sources of aerosols that can affect regional and global climate. For many years, air quality has been one of the main environmental issues in urban areas, particularly in megacities, defined as areas with more than 10 million residents. Population growth and increasing industrialization have resulted in a higher demand for energy, greater use of fossil fuels and more emission of pollutants into the atmosphere. The main emissions that affect air quality include sulfur oxides, nitrogen oxides, carbon monoxide and atmospheric particles, or aerosols, mostly consisting of soot, sulfates, nitrates and organic matter.

In the Mexico City metropolitan area, emissions of pollutants reach millions of tons per year, and atmospheric concentrations of pollutants routinely exceed the standards recommended by the World Health Organization. As a result, there has been an increase in diagnosed incidences of chronic bronchitis, asthma, reduction of pulmonary capacity and premature mortality rates. These same air pollutants, particularly aerosols, can also be transported long distances and can cause changes in regional weather and climate by altering the radiation balance of the atmosphere and influencing cloud formation. Understanding the role that aerosols play in climate change is the focus of the DOE Office of Science Atmospheric Science Program.

“The MILAGRO campaign brings an international research team of hundreds of scientists and students to the Mexico City area, where they will be joined by a large group of Mexican investigators and will collaborate with Mexican governmental agencies,” said David Thomassen, acting director of the Office of Biological and Environmental Research in DOE's Office of Science, which is sponsoring Gaffney's portion of the research project. “This important effort will not only contribute to the world's understanding of environmental issues, but will also provide important scientific training to the many students working on the project as well.”

The goal of MILAGRO is to conduct measurements of pollutants and to study the atmospheric processes involved in their distribution in the environment. Four simultaneous measurement campaigns will be conducted over the coming weeks:

• MCMA-2006 will focus on air quality in the Mexico City metropolitan area;
• MIRAGE centers on the chemical and physical transformations of the gaseous and particulate pollutants;
• INTEX will focus on the transport of pollution; and
• MAX-Mex– the portion of the research effort headed by Gaffney – will focus on aerosols, especially their transport, transformation and chemical and optical properties.

Aerosols can have important effects on human health and climate, and can affect the photochemistry of the atmosphere.

“The MAX-Mex campaign will characterize aerosol formation and changes in aerosol composition,” Gaffney said. “The field study will focus on chemical, physical and optical characterization of the aerosols, on aerosol transformations, and on the effects of the megacity aerosol plume on the regional radiative balance in and near this megacity source.”

The MAX-Mex program will use two aircraft for data collection: The DOE Gulfstream aircraft operated by Pacific Northwest National Laboratory is well instrumented to measure aerosol properties and gas contributions; and an additional aircraft will provide information on aerosol distribution and plume extents. In addition, different types of equipment will be installed at three ground-based sites, again focusing on aerosol emission and formation, properties, chemical and physical transformations and effects on climate.

The current research is a more extensive version of a 2003 study which involved the first extensive environmental measurements in Mexico City. The MILAGRO science teams have spent the past two years designing the details of the research effort so that they dovetail into a comprehensive measurement plan. The 2003 data, in combination with the data to be obtained in March, will allow a uniquely thorough analysis of the sources and evolution of airborne fine particles in a developing world megacity.

In addition, the data collection and analysis provides scientific training for graduate students, postdoctoral researchers and undergraduate students from participating Mexican, U.S. and other international institutions.

Funding for MAX-Mex is from the Atmospheric Science Program of DOE's Office of Biological and Environmental Research in the Office of Science.

Argonne National Laboratory brings the world's brightest scientists and engineers together to find exciting and creative new solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America 's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

For more information, please contact Steve McGregor (630/252-5580 or media@anl.gov) at Argonne.