Report Updates Benzo(a)pyrene Emissions Estimates for the Great Lakes Region

Report Updates Benzo(a)pyrene Emissions Estimates for the Great Lakes Region

The Great Lakes Commission today released a report detailing air emissions of benzo(a)pyrene, also known as b(a)p, within the Great Lakes region. B(a)p was identified in 1997 as one of twelve high-priority toxic substances by the U.S. and Canadian governments and the governments committed to reducing b(a)p releases as part of the Great Lakes Binational Toxics Strategy (GLBTS). Concentrations of this chemical in the sediments of many portions of the Great Lakes basin are above levels believed to cause harm to wildlife. B(a)p is also believed to be an important contributor to human cancer risks. Although it accumulates in sediments and the food chain, the great majority of b(a)p releases are to the atmosphere.

Today’s report represents an update of the benzo(a)pyrene emissions estimated in the 2002 regional toxic air emissions inventory released last year. The inventory and report have been compiled by the air pollution control agencies of the eight Great Lakes states and the province of Ontario. In compiling the revised b(a)p inventory, the state and provincial agencies participated in a close inspection of their prior emission estimates, compared information among the states and province, and evaluated the latest scientific information. Changes and corrections made to the original estimates of 2002 emissions were significant in many cases. In all, the estimate of total air emissions within the region decreased by 32% to 59,000 pounds. Among the source categories showing the largest emissions in the revised inventory are metal production, residential wood burning, petroleum refining, forest fires and the burning of household garbage and yard wastes.

The report can be used by the state, provincial governments in the region to further assess the risks posed by b(a)p in the Great Lakes environment and to evaluate the effect that future efforts to control emissions may have. “This emission inventory for the Great Lakes region is very useful in our efforts to reduce and track releases under the Binational Toxics Strategy,” said Steven Rosenthal of the U.S. EPA a co-chair of the b(a)p working group under the GLBTS. “Because b(a)p doesn’t travel as far in the environment as many persistent toxic substances, a regional inventory has increased relevance for efforts to protect the Great Lakes.”

Although it is not possible to quantify the change in b(a)p emissions within the region over the past 10-15 years, the report concludes that emissions from many of the sources that are currently well known have declined substantially over that period. Emissions from industrial facilities and automobiles in particular have declined due to the implementation of emission controls. However, measurements in the environment of benzo(a)pyrene have not shown a substantial decline, suggesting the possibility that additional sources exist that are not yet able to be quantified. “Although there has been success in controlling many of the well-know sources, there may be others that we haven’t yet detected or thoroughly studied,” said Tom Tseng of Environment Canada, also a co-chair of the b(a)p working group. “Scrap tire fires, burning agricultural wastes and use of coal-tar and creosote are areas where we believe emissions may be large, but don’t yet have the science to put a number on how large.”

The report concludes that in addition to identifying and estimating emissions from other sources, efforts are also needed to assess the risks posed by benzo(a)pyrene emissions and to more fully compare emissions information with that from our environmental monitoring networks.

The report is available at www.glc.org/air.

For more information, contact Jon Dettling at 734-971-9135, dettling@glc.org