By RACHEL IOVAN
LANSING – Some Michigan county health departments are looking forward to a new way to track the source of beach contaminants using an experimental low-powered laser.
A laser shined through an E. coli colony scatters light creating an image from which scientists can predict the species from which it came. Graphic: Bin Chen
The laser, developed at Purdue University, would shine through E. coli samples to create images that could be cross-referenced with a library of samples to determine what kind of animal the bacteria came from, according to toxicologist Shannon Briggs of the Department of Natural Resources and Environment (DNRE).
E. coli comes from a number of sources, including human sewage, agriculture, gulls and other wildlife and can cause illness in humans.
In 2009, authorities closed 82 beaches due to 212 incidents where E. coli levels exceeded Michigan’s water quality limits.
Closures this year included the New Buffalo City Beach in Berrien County, Van Buren Beach in Wayne County, Baypoint Beach in Macomb County, Lighthouse County Park in Huron County and South Beach in Van Buren County.
Briggs said that the laser method could make finding the source of contamination quicker and cheaper than current techniques, which can take up to 24 hours for results. Turnaround time with the laser technique could be as short as six hours.
Different types of E. coli. Graphic: Bin Chen
Tom Reichard, the environmental health director for the District 10 Health Department, which monitors 22 beaches along Lake Michigan in Mason, Oceana and Manistee counties, said when samples are taken now, officials can only speculate about the source of contamination such as looking at animal presence and boats moored in the area.
That the technique isn’t as accurate as Reichard would like. “When we get a sample of E. coli right now, we’re taking our best guess at what the source is.”
Sonia Joseph Joshi, the Michigan Sea Grant outreach coordinator based in Ann Arbor, said the concentration of E. coli determines whether a beach can stay open but doesn’t show what kind of animal produced the contamination.
“If you have a beach plagued with closures because of water quality but you don’t know the source, it’s hard to fix the problem,” said Joshi.
If the technology is approved, beach managers could ideally take samples themselves, she added.
Adam London, the environmental health manager at the Ottawa County Health Department, said that the laser technique was described at the county’s recent annual water quality forum where researchers presented ideas for improving water quality.
“We would like to have a better understanding of what sources contribute the most E. coli. Having that knowledge would empower us to address those sources directly,” said London.
Purdue University Calumet professor Bin Chen and colleagues produced laser technology that could help detect beach contaminants. Photo: Bin Chen.
The technology was initially developed to quickly track contaminants in food supplies and researchers are now finding broader applications.
Briggs said that in October 2012, the Environmental Protection Agency will release tougher standards for microorganisms in water, and the laser technique could help health departments meet those requirements.
She said the technology could be used across Michigan in the future, but not until researchers refine the technique and build their library of samples.
David Rockwell of the beach water quality forecasting center at the National Oceanic and Atmospheric Administration based in Naperville, Ind., said, if accuracy could be improved from 80 to 95 percent, it would probably be a valuable tool for beach managers because the technology is cheap and fast.
“You can do genetic testing to find out the source, but it’s expensive. The laser technique would be much cheaper,” said Rockwell.
Rockwell said researchers estimate the cost of each laser at $1,000.
But District 10’s Reichard noted that there’s not much funding available to test beach water.
“There’s no money to do the sampling. The state has had small grants that go to only a handful of inland lakes,” said Reichard, “We need to do anything that would get the results to us faster, but that is always limited by cost.”
Nearly all funding for Great Lakes water quality testing comes from the federal government, but inland lakes aren’t eligible for those grants, so communities must rely on the state, he said.
Reichard said most people believe beaches are sampled consistently, but most inland beaches in Michigan aren’t.
According to a 2009 DNRE report, only 37 percent of Great Lakes beaches and 32 percent of inland beaches in Michigan were monitored for water quality.
© 2010, Capital News Service, Michigan State University School of Journalism. Not to be reproduced without permission.