5 On Your Side

Tests find mold, fecal bacteria in children's lunch boxes

Posted February 9, 2012 6:00 p.m. EST
Updated February 9, 2012 7:25 p.m. EST

— Parents wouldn’t serve their children peanut butter and jelly with mold or a ham sandwich with a side of fecal coliforms, but those combinations are popping up in lunch boxes, according to a 5 On Your Side investigation with North Carolina State University.

WRAL News teamed up with an N.C. State scientist and her graduate students to study germs in children’s lunch boxes and on trays at fast food restaurants and mall food courts.

"We're looking for evidence of fecal contamination, the presence of listeria, which is an indication of some sort of environmental contamination, and the presence of staphylococcus, which can come from mucous membranes or hands, or things like that,” said Dr. LeAnn Jaykus, a food science professor at N.C. State.

Listeria and staphylococcus can be found everywhere, and, in small doses, are not typically harmful. Listeria causes disease most often in pregnant women and the elderly. However, fecal coliform, in any amount, is a sanitation concern.

Jaykus and her graduate students swabbed about 100 lunch boxes at Exploris Middle School in Raleigh, which agreed to be part of the study. They also gathered 45 samples from trays at fast food restaurants and mall food courts around Raleigh and eastern North Carolina.

“The trays were really boring,” Jaykus said. “We found no evidence of fecal contamination, no evidence of listeria (and) no evidence of staph.”

She attributes that to the fact that most restaurants wiped off their trays between customers and used paper liners to keep the trays clean. The students’ lunch boxes, on the other hand, “were fun” to examine, Jaykus said.

“I mean, that’s classic mold right there,” she said, pointing to results from one of the lunch boxes.

Half of the lunch boxes tested positive for low levels of staphylococcus, and 3 percent tested positive for listeria. Jaykus says those levels “would not be of any kind of concern.”

"The fact that your lunch box is dirty is kind of grody, but it's not necessarily an indication of a health problem,” she said. However, the presence of fecal matter did concern her.

“This was actually a surprise to me,” she said. “I would say that about 15 percent of the (lunch box) samples showed some evidence of fecal contamination.”

Jaykus says the likely source is kids who don’t wash their hands after using the bathroom. She suggests parents talk with their children about proper hygiene and wash their lunch boxes every week.

“You could see mold growth. You could see caked food product. You could see that these lunch pails had not been cleaned for a very, very long time,” Jaykus said. “Just so the moms and dads out there know, after we took the samples, we did sanitize the lunch boxes.”

The study focused on risks associated with bacteria, not with viruses. Jaykus says her group plans to publish the results of the tests.

More germ statistics

Surfaces with highest concentration of germ contamination:

1. Gas pump handles (71% of surfaces tested had a high level of germs)
2. Mailbox handles (68%)
3. Escalator rails (43%)
4. ATM buttons (41%)
5. Parking meters/kiosks (40%)
6. Crosswalk buttons (35%)
7. Vending machine buttons (35%)

(Source: Kimberly Clark study/MainStreet.com)

In schools, surfaces with the most germs:

1. Cafeteria table
2. Computer mouse, which harbored nearly twice as many bacteria than desktops,
3. Bathroom paper towel handle
4. Water fountain
5. Bathroom sink faucets,
6. Library table and
7. Computer keyboard.

(Source: University of Arizona study/PRNewswire)