Regional emissions inventory documents releases of toxic substances in the Great Lakes region

Ann Arbor, Mich. – The Great Lakes Commission has announced the release of the newest edition of the Great Lakes Regional Toxic Air Emissions Inventory. Based on estimates of 2005 air emissions provided by the eight Great Lakes states and the province of Ontario, the inventory covers emissions from more than 2,500 categories of air pollution sources, including industrial facilities, automobiles, residential energy use and many others.

This is the seventh year of data that has been compiled for the regional inventory and the first in three years. Its completion marks continued progress toward obtaining comprehensive and current information on toxic emission sources in the Great Lakes region and achieving data reporting consistency among the eight states and Ontario.

The inventory includes releases of nearly 200 chemicals, intended to represent all those identified as Hazardous Air Pollutants in the Clean Air Act and those compounds significantly contributing to the contamination of the Great Lakes Emissions estimates were from nearly 12,000 industrial facilities across the region. In all, it estimates approximately 2.3 billion pounds of toxic air emissions for the entire region, which covers a total population of more than 90 million people.

A regional inventory of this type is particularly valuable for the Great Lakes region due to health concerns from pollutants, such as mercury, which enter the Great Lakes from the air. Their large surface areas, long water retention times and other factors make the Great Lakes particularly susceptible to such problems. Many toxic pollutants that are originally released to the air will deposit to land and waterways in large quantities, either in precipitation, attached to particles, or as gasses.

Total estimated emissions in this latest inventory are lower than in previous years, but do not necessarily indicate a decline in overall emissions. Changes in methodology, including the addition of more types of sources and improvements in estimation techniques and measurements, can lead to changes in emission estimates even if actual emissions have not changed.

The Great Lakes regional inventory is a longstanding and unique partnership among the eight Great Lakes states and the province of Ontario, coordinated by the Great Lakes Commission. The nine participants not only share emissions estimates as part of the regional project, but also work together to improve estimation methods and to share and compare their procedures and information. This partnership has led to significant improvements in the toxic air emissions inventories on both sides of the border and has provided the participating states and province a unique opportunity to work collaboratively in addressing the potential threat these chemicals pose. Beyond just sharing of information, this project leads to information that is more consistent in terms of how it is produced and reported.

The inventory data have been used for a variety of purposes by the participating states and province, as well as by other agencies and organizations. For example, the data have been used to assess health risks, prioritize state and federal pollution prevention activities, support permit review and tracking, assist community groups and researchers, and much more.

The report of the 2005 Great Lakes Regional Toxic Air Emissions Inventory is available online through the Great Lakes Information Network at In addition, the emissions estimates will be available in the coming months for viewing through the Centralized Air emissions Repository On-Line (CAROL), an interactive website capable of producing maps, charts and tables of the toxic air emissions information. The project has received support from the U.S. EPA’s Office of Air and Radiation.

For immediate release: April 2, 2009  |  Download PDF
 Jon Dettling,, office: 734-971-9135


The Great Lakes Commission, chaired by Gov. Patrick Quinn (Ill.), is an interstate compact agency established under state and U.S. federal law and dedicated to promoting a strong economy, healthy environment and high quality of life for the Great Lakes-St. Lawrence region and its residents. The Commission consists of governors’ appointees, state legislators, and agency officials from its eight member states. Associate membership for Ontario and Québec was established through the signing of a “Declaration of Partnership.” The Commission maintains a formal Observer programinvolving U.S. and Canadian federal agencies, tribal authorities, binational agencies and other regional interests. The Commission offices are located in Ann Arbor, Michigan.

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