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GLIN==> Illinois-Indiana Sea Grant News: New Test Makes Tracking Toxic Mercury in Polluted Waters Easier

October 19, 2005
Sources: Bob Hudson, U of I associate professor of aquatic chemistry, 217-333-7641, rjhudson@uiuc.edu
Chris Shade, former U of I Ph.D. student
New Test Makes Tracking Toxic Mercury in Polluted Waters Easier
Urbana, IL -- Two Illinois-Indiana Sea Grant researchers have applied for a process patent on a mercury analysis technique that will make testing for methylmercury, a highly toxic environmental contaminant, less expensive and much faster.
"The main environmental risk to people and wildlife from mercury pollution comes via consuming methylmercury that has accumulated in fish," said Robert Hudson, a University of Illinois environmental chemist.

In fact, fish from 13 lakes in Illinois have tested high enough in methylmercury to cause the Department of Public Health to issue specific fish consumption advisories. All lakes and rivers, however, are subject to a general advisory that pregnant women, nursing mothers, and children younger than 15 years old should limit their consumption of predator fish to one meal per week.

According to a 2003 study (Schober, S.E., et al. 2003. JAMA 289:1667-74), 8 percent of women of childbearing age in the United States had mercury levels in their blood above the U.S. Environmental Protection Agency's reference level, which is set to protect developing fetuses from neurological harm.
To date, the number and scope of environmental studies of mercury have been limited due to the extreme cost of the testing. The new test promises to drastically reduce this cost so that scientists can do much more monitoring and design better remediation strategies for contaminated sites.
Most mercury finds its way into the atmosphere from human sources, such as coal-fired power plants, metal smelters, and waste incinerators. It is then deposited on land and surface waters in rain. However, not all mercury is equally toxic. Pollution sources mostly emit inorganic forms of mercury, but methylmercury accumulates in fish. Methylmercury is produced from inorganic mercury by naturally occurring bacteria in oxygen-depleted zones of wetlands and river and lake sediments. 
"The rate of methylation varies from one sediment or wetland to another, so if we can figure out where rates of methylation are high, cleanup efforts can be directed to where they will have the most impact," said Hudson. An example of such an effort is his lab group?s recent study of the highly polluted Grand Calumet watershed at the southern tip of Lake Michigan. In conjunction with this research, a former U of I doctoral student, Chris Shade, and Hudson developed the new testing procedure.
"Although you still have to collect samples carefully and extract minute amounts of mercury from them, our new procedure is much less time consuming and can be automated to make the process of mercury analysis a lot cheaper," said Shade, who is starting Quicksilver Scientific, an analytical laboratory, to offer the methylmercury analysis commercially.
Shade says that systematic surveys of methylmercury in lakes and rivers would be less expensive than monitoring fish for the compound.
 "People would simply avoid fish from high-risk lakes and rivers and consume fish from certified, low methylmercury lakes and rivers instead," he said.
This research was recently published in the October issue of Environmental Science & Technology ( http://pubs.acs.org/journals/esthag/). In addition to Sea Grant, this research was funded by the Council on Food and Agricultural Research (C-FAR) and the U of I College of ACES.
The Illinois-Indiana Sea Grant College Program is one of more than 30 National Sea Grant College Programs. Created by Congress in 1966, Sea Grant combines university, government, business and industry expertise to address coastal and Great Lakes needs.  Funding is provided by the National Oceanic Atmospheric Administration (NOAA), U. S. Department of Commerce, the University of Illinois at Urbana-Champaign and Purdue University at West Lafayette, Indiana.

Irene Miles
Illinois-Indiana Sea Grant
376 NSRC
1101 W. Peabody Dr.
Urbana, Il 61801
(217) 333-8055
FAX (217) 333-8046