An ill wind blows no good

Matthew Cimitile, cimitile@msu.edu
Great Lakes Echo 4/21/09

As contaminated sediment is cleaned up in the Great Lakes, persistent pollutants continue to blow in, threatening again to poison soil and harm human health.

That has some experts questioning if it’s worthwhile to spend money to remove toxic sediments if they will once more become contaminated in a matter of years.

“We have been very hung up on cleaning the watershed because we believed it was the source of contamination in the lake, but in recent decades contamination has come through the air,” said Mel Visser, former vice president of environmental health safety at Upjohn Pharmaceutical in Michigan and author of Cold, Clear, and Deadly: Unraveling a Toxic Legacy.

“Even if you cleaned all the lakes tomorrow you wouldn’t do anything to the water because the concentration of these chemicals is controlled by the amount in the air,” said Visser, whose book describes current sources of chemicals that continue to pollute the Great Lakes’ air, food supply and water.

The Great Lakes Legacy Act signed in 2002, provides funding to clean up Great Lakes sediments. It authorized $270 million over five years towards this task. And it was reauthorized in 2008 to provide another $108 million for two more years.

So far, the act is responsible for removing 38,000 pounds of lead and 160 pounds of PCBs from Detroit River’s Black Lagoon and 50,000 cubic yards of petroleum-contaminated sediment and soil from Newton Creek in Wisconsin. It is now financing the dredging of PCB and pesticide laden sediment from the Grand Calumet River in Indiana and other projects.

Environmental groups say it is money well spent.

“These are highly polluted areas, areas of high concern… that the EPA has shown damage fish and impact the environment and human health,” said Chad Lord, legislative director of the Healing Our Waters – Great Lakes Coalition. “Work so far [to clean up these spots] has really improved the quality of life.”

But persistent organic pollutants — known as POPs – continue to threaten health. Studies have linked these chemicals to diseases and declines in wildlife and to behavioral, developmental and reproductive abnormalities in people, according to the EPA. They are considered possible carcinogens.

The U.S. banned many POPs like DDT, PCBs and toxaphene in the 1970s. Their levels in the Great Lakes dropped significantly, some by more than 50 percent in a short span. Since then, however, many of these chemicals have leveled off and persisted in the environment, finding their way into waterways and sediment and bioaccumulating in the food chain.

“They are still present and not going away,” Visser said. “Outlawing them in the U.S. does not simply get rid of them.”

A 2009 EPA study looking at contaminants in fish tissues from a wide sample of U.S. lakes found that many of these POPs continue to exist. Dioxins were detected in 81 percent of fish samples, according to the study published in the journal Environmental Monitoring and Assessment in March. Furans were found in almost all of them. Other contaminants like Mercury exceeded EPA standards in nearly half of the lakes.

“Mercury and PCBs were detected in every body of water that we went to and along with dioxins, DDT and chlordane were the most frequently found chemicals [in U.S. lakes],” said Denise Keehner, director of the standards and health protection division at the EPA.

More than 100 lakes were sampled from the eight Great Lakes states.

POPs found in U.S. lakes come from past and current releases. Millions to billions of pounds of these chemicals were released into the environment; some are stored in soils.

Today, as fields are plowed, soil is mixed and brings contaminants below ground to the surface. When the weather heats up, contaminants evaporate into the atmosphere, said Jim Ludwig, a retired ecotoxicologist from Michigan.

“This leads to the general effect seen in many POPs where they evaporate more readily in warmer climates and are exported through the air to condense in colder ones,” said Ludwig, who has spent decades studying the effects of contaminants on Great Lakes’ wildlife.

The other main source comes from many nations like China, Russia and India which continue to use POPs for pesticides and industrial uses. Once emitted into the atmosphere, the chemicals drift throughout the planet, Ludwig said.

“The stuff coming out of the air reflects whatever is discharged globally and the way global circulation works if you discharge something in England it will get back to England in three weeks,” he explained.

As sources around the globe emit such chemicals, many find their way into the Great Lakes, Visser said. Just making sure everything around the lake is protected is no longer sufficient.

The problem posed by airborne POPs, is that they are a global headache that turns into a local one for places like the Great Lakes, Ludwig said. Furthermore, those pollutants, primarily the result of evaporation from soil and surface water, are toxicologically different from the point source pollutants that are found in the ground.

That means even though cleaned sediments will once again become dirty, it’s still worth cleaning them up.

“The persistent chemicals in the sediment affect biological development, while those in the air affect behavior,” Ludwig said, “which is why you have to clean up both.”

Along with the legacy act, President Barack Obama has proposed $475 million for Great Lakes restoration in his 2010 budget to address a number of issues including contaminated sediment.

“We see the effects from atmospheric deposition and it is a problem that needs to be addressed,” Lord said. “But the longer we wait to pull stuff out of the rivers and harbors the more damage and expensive it will be.”

Wednesday: International pollutants still circulating at home threatening water quality