Technology brought us the wireless TV remote, the wireless phone and now the wireless … poop detector?
No, it doesn’t let you channel surf or chat on the go, but the new E. coli detector could keep you from getting sick.
Researchers at Environmental Technology Solutions in Arizona and John Hopkins University designed a wireless E. coli detector that takes much less time than current methods to analyze water for harmful bacteria, according to a recent report in Environmental Engineering Science.
The wireless E. coli detector prototype. Photo: Joseph Geary
Testing water for E. coli typically takes one to three days to give results, said Herb Fredrickson, associate director of ecology for the U.S. EPA. By that time, any health threat may have long passed.
The new device measures bacteria and sends the information to monitoring stations much faster – less than eight hours for low concentrations and less than an hour for high concentrations. That is significant because closing a beach based on a day-old sample means people may have already been exposed.
Current beach testing typically involves culturing water samples to see if the bacteria form colonies, Fredrickson said. The beach managers visually inspect the samples.
The wireless detector inspects the sample itself — no eyes needed, said Gary Nijak, Jr., director of technology at Environmental Technology Solutions.
The detector instigates a reaction between sugars and E. coli that releases fluorescent light. An internal sensor measures the fluorescence to determine E. coli levels.
Researchers showed off a prototype at a weeklong demonstration on the St. Joseph River in South Bend, Ind. in the summer of 2009. Samples were drawn every six hours over six days. Fifteen samples were compared to current methods and 13 were spot on.
When there were large spikes in E. coli, as expected when storms cause sewers to overflow, the detector recognized those levels within minutes.
The kind of timeliness is very attractive to beach managers, Fredrickson said.
“When closing beaches, we are interested in knowing E. coli levels right away,” Fredrickson said. “If you test at the beginning of Labor Day weekend, and things change, that’s a lot of people getting sick.”
Fredrickson said the feds have been “working very hard for many years” on a replacement for the culture method, but, so far, nothing has proven as accurate. New methods often fail because they’re time consuming, can’t quickly adapt to changing water conditions and often require a trained expert to operate.
And while the study has caught the attention of beach testers, the researchers are still looking for help to take the next step, Nijak said.
“We’re just a group of environmental and chemical engineers, so we need partners to take it to the next level,” Nijak said. “We’ve proven it’s viable, but we’re reaching our own limits.”
Two issues are size and power. The prototype is about a square foot around and 6 inches tall. Nijak would like it to be even smaller.
For the trial run on the St. Joseph River, they used car batteries to power the detector and the information was sent to a laptop. But more efficient batteries and a microprocessor instead of a laptop would significantly cut down power requirements, he said.
The biggest hurdle will be getting the technology into the hands of beach managers and water treatment officials who are used to doing things a certain way and may be handcuffed financially, Nijak said.
“Most municipalities are comfortable with their system and it may be tough to get that buy in,” he said. “And unless the municipality is progressive, there’s probably not funding built in for these kinds of things.”
Nijak isn’t sure how much the detector would cost, and, since they’re still refining it, they haven’t yet reached out to beach managers.