EPA funds Great Lakes environment study by Indiana University scientists

  • Jan. 6, 2015


BLOOMINGTON, Ind. -- The U.S. Environmental Protection Agency has awarded Indiana University a $6 million grant to continue a project that measures levels of airborne toxic chemicals being deposited to the Great Lakes.

The researchers have already discovered surprisingly high levels of chemical concentrations in two major lakeside U.S. cities.

The Integrated Atmospheric Deposition Network project is led at IU by Distinguished Professor Ronald Hites and by assistant scientists Marta Venier and Amina Salamova in the School of Public and Environmental Affairs. The project began in 1990 under an agreement between the U.S. EPA and Environment Canada. Indiana University has been in charge of the U.S. portion of the study since 1994. This newest grant continues the project until 2019.

"Atmospheric deposition is one of the main ways that toxic chemicals get into the Great Lakes," said Todd Nettesheim, from the EPA's Great Lakes National Program Office. "The Indiana University team is leading a critical long-term Great Lakes monitoring program. They are tracking how much of the chemicals get into the lakes, potential source regions and our progress improving the environment.”

Hites said the grant will enable IU to provide important trend data on chemicals -- including polychlorinated biphenyls, known as PCBs; chlorinated pesticides such as DDT; polycyclic aromatic hydrocarbons; and flame retardants -- reaching the Great Lakes through the atmosphere.

"Cities have a huge impact on the chemical levels, and we want to pin down those sources as the pollutants leak into the lakes,” Hites said.

The Integrated Atmospheric Deposition Network project is collecting air samples at urban stations in Chicago and Cleveland, as well as at regular intervals at master stations on each of the five Great Lakes. Hites said his team has discovered that concentrations are dramatically higher in cities, not only for industrial chemicals such as PCBs but also for some pesticides. While DDT was widely used in agriculture before being banned from most uses in the U.S. in the 1970s, it was also sprayed to control mosquitoes in cities. Another pesticide, chlordane, was used to treat homes for termites. Apparently, these chemicals stay in the urban environment for decades, before getting into the air and being transported to the lakes.

The Great Lakes are the largest surface freshwater system on the Earth, containing about 84 percent of North America's surface fresh water and about 21 percent of the world's supply. Roughly 10 percent of the U.S. population and more than 30 percent of Canada's population live in the Great Lakes basin.

For the project, air samples are taken every 12 days, providing a mass of data that allow scientists to study trends in the deposition of chemicals to the Great Lakes and that help policy-makers better understand how to manage the effects of pollution.

"We’re pleased that the EPA is continuing the grant because a few measurements over a few months don't tell you much," Hites said. "For this project to be effective, we have to do the measurements over a long time period.”

While concentrations of some of these chemicals in the air are low, many do not easily break down. They are persistent, and they bioaccumulate in the tissues of animals. For many people, consumption of fish and wildlife is the primary pathway for exposure to the chemicals. As a result, government agencies continue to issue advisories against eating Great Lakes fish.

PCBs have been shown to cause cancer in animals and have been linked to other serious health problems, including effects on the immune, reproductive, nervous and endocrine systems.

In addition to the urban data, Hites said he has been surprised that while concentrations of some of these chemicals are going down, the decline isn't as fast or steady as might have been expected. For example, the manufacture and use of PCBs was banned in the U.S. in 1976, but they have remained in use in products that were produced before that time. Great Lakes PCB levels went down rapidly for a time and now are decreasing more gradually.

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