With just a flicker of blue light, school officials soon might know for sure whether their food-service employees washed their hands thoroughly before serving lunch. New light-scanning technology borrowed from the slaughterhouse promises to help hospital workers, restaurant employees–one day, even kids–make sure that hand washing zaps some germs that can carry deadly illnesses. A device the size of an electric hand dryer detects fecal contamination and pinpoints on a digital display where on a person’s hands more scrubbing is needed.
eMerge Interactive Inc., a struggling technology company in Sebastian, Fla., is hoping to tweak light scanners it already sells to beef plants to detect the same kinds of nasty germs on humans.
The blue-light scanners could dramatically improve hygiene among employees who forget to wash their hands after bathroom breaks. This practice is a leading cause of food poisoning that reportedly afflicts tens of millions of Americans every year.
Studies show people typically fail to scrub around fingernails and between fingers adequately. The government recommends people wash their hands for at least 20 seconds; researchers find many people do not even use soap.
“People are not good at hand washing,” said Janet Anderson, a nutritionist at Utah State University. “We find that unless sinks are very close to where people are handling food, they don’t wash their hands well.”
eMerge, which demonstrated an early prototype for The Associated Press, said its first clean-hand scanners could go on sale as early as year’s end to schools, restaurants, nursing homes, hospitals, and day-care centers. Using identification cards, the devices can even record which employees scrubbed acceptably and which ones still have dirty hands.
“Being able to tell whether there’s fecal matter is a major improvement,” said Jim Mann, executive director of The Handwashing Leadership Forum, a group in Illinois that studies food-borne outbreaks.
Mann called the scanning technology promising but “not a silver bullet,” because it cannot detect pathogens such as salmonella or viruses that do not always spread initially in fecal contamination. Salmonella can be present in raw eggs, for example.
Using a specific light wavelength, the scanners cause a fluorescence in even minuscule amounts of fecal contamination that could carry dangerous bacteria like E. coli; it shows up on a built-in display as a bright red spot on a person’s dirty hand.
In meat plants, the scanners look for evidence of chlorophyl, the green pigments found in plants and grasses common to cow diets. The clean-hands scanners will need to search for other signatures, not just chlorophyl, that might signal contamination by meat eaters: Human diets are much more diverse than cattle’s.
People on the popular Atkin’s diet, for example, would have almost no chlorophyl in their systems, said eMerge’s executive vice president, Richard Stroman. He declined to say which new markers the company is investigating, calling that a trade secret.
“If you only eat beer and cheese pizza, what kind of signatures are you going to get?” asked Jacob Petrich, a biophysical chemist at Iowa State University who invented the meat-scanning technology along with two scientists, Thomas A. Casey and Mark A. Rasmussen, at the Agriculture Department.
Petrich suggested that hospitals, restaurants, or schools could ask employees to swallow chlorophyl tablets. “This is do-able, it’s just a question of technology, of how you look at the spectral signatures of diets,” he said.
A report last year by the U.S. General Accounting Office (GAO) identified 195 food-borne illness outbreaks in schools nationwide between 1990 and 1999, according to the American School Food Service Association (ASFSA). This represents roughly 3 percent of all outbreaks reported during that period.
State health departments provided information to the GAO regarding 59 large food-borne illness outbreaks in schools–those where at least 50 people were affected. Of these, 19 outbreaks were caused by sources unrelated to school food service, such as food from students’ homes. An additional 19 outbreaks were attributed to improper food handling practices within schools, and 8 were attributed to the contamination of food before its delivery to the schools. It is not known where the food involved in the remaining 13 outbreaks was contaminated.
The clean-hand scanning technology “looks good and could be very useful in school kitchens,” said Erik Peterson, director of public awareness and media relations for ASFSA. “I would say its widespread use in schools will depend in large part on the cost of the units.”
An eMerge spokesman said the company was considering a price in the $2,000 range for the scanners.
eMerge Interactive Inc.
American School Food Service Association