Despite warnings from the state Department of Environmental Quality, Brenda Brouillet is glad to dig up soil containing toxic chemicals that scientists have linked to serious illnesses.

Wearing latex gloves and bearing a small trowel, Brouillet spent Wednesday morning meticulously scooping clods of soil from West Michigan Park in Saginaw Township, where state officials suspect the Tittabawassee River may have carried dangerously high amounts of the toxic compound dioxin.

"This is going to be where we we're able to draw some real conclusions," said Brouillet, a supervisor from the DEQ's Saginaw-Bay District office. "We didn't really have enough information before."

Beginning this week, the agency will draw more than 200 plugs of soil from a 30-mile stretch along the Tittabawassee River flood plain, from just north of Midland to where the Tittabawassee merges with the Saginaw River.

Workers will take samples from 11 sites that include residents' yards, public parks, and fields where livestock graze and farmers grow corn, hoping to discover if dioxin levels surpass levels deemed safe for human contact.

Tests at three sites along the river from 2000 and 2001 revealed concentrations of dioxin -- the generic name for a compound that is the toxic byproduct of chlorine manufacturing, incineration and other combustion processes -- at levels higher than any previously recorded in Michigan.

However, the total of 35 samples from those sites was not enough to show whether the chemicals were isolated at those locations, or more likely, present throughout the Tittabawassee flood plain, said Allan Brouillet, Brenda's husband and a DEQ enforcement specialist.

"We're as anxious as anybody to find out," he said.

Precise process

Allan Brouillet uses a steel hand auger to drill four holes at each test location, pulling out plugs of soil at depths of 3 inches, 6 inches, and 12 to 15 inches.

Dioxin levels typically drop at deeper levels of the soil because the compound binds to particles in the soil and does not wash away, but none of the samples taken during the first phase of testing is lower than the normal background levels of 33 parts per trillion or lower, Brouillet said.

A report from the DEQ to the Agency for Toxic Substances and Disease Registry, a branch of the federal Centers for Disease Control, states that the dioxin found along the flood plain may have come from a wastewater treatment facility at Dow Chemical Co.'s Midland plant that overflowed during the historic floods of 1986.

Dow officials dispute the claim.

When the Tittabawassee overran its banks during the floods, residents who live nearby said that for days water completely covered West Michigan Park, which is wide enough for several soccer fields.

Brouillet dumps about a pound of the soil into a Ziploc baggie for analysis of its type, and smaller samples are sealed in small jars that will go to Triangle Labs, a private laboratory in Durham, N.C.

Triangle chemists pioneered the procedures used to find the minute quantities of dioxin -- measured in parts per trillion -- that provide scientists with the data needed to evaluate health risks, said Don Harven, the company's vice president.

Dioxin tests, which typically cost as much as $1,200 per sample, are especially complex. However, they remain in demand.
"(Dioxin levels) are an ongoing concern when it comes to food, real estate, and a variety of things," said Chad Roper, director of business development.

"We deal with a pretty wide array of industries."

The company follows testing procedures prescribed by the federal Environmental Protection Agency.

First, a 10-gram soil sample is rinsed with solvents that extract the dioxins and other chemical compounds.

The dissolved compounds then are filtered and boiled down into a highly concentrated droplet -- about one cubic centimeter -- that is inserted into a gas chromatograph, a microwave oven-sized device that essentially boils the sample until the compounds vaporize.

"It's like a very powerful convection oven with very precise temperature control," Harven said.

At 482 degrees Fahrenheit, about the same as the temperature inside a commercial pizza oven, the different compounds in the sample become a gas.

Based on known standards of molecular weight, a device called a mass spectrometer can analyze the data from the chromatograph and determine the type of chemicals in the sample.

The lab is testing specifically for the seven types of dioxin that scientists have linked to health problems, including cancer and birth defects.

"With this process we can measure down to within 15 to 20 percent accuracy," Roper said.

A measurement of one part per trillion is comparable to a single pinch of salt spread among 10,000 tons of potato chips, or one bad apple out of 2 billion barrels, Roper said.

"We're talking about infinitesimally small amounts of these compounds," he said. "But that's important because (dioxins) can have serious effects in those amounts."

The results from the testing should arrive within a few months, Allan Brouillet said. The DEQ will share the findings with the state Department of Community Health and the Agency for Toxic Substances and Disease Registry, and will discuss options for clean-up or other measures.

The results almost certainly will prompt more tests as well, he said.

"We would love to be able to say that all there is to find, we found the first time," he said.