A study revealing that sponge-type dish scrubbers used daily in the kitchen can harbor up to 54 billion bacteria is again drawing attention.
Last Friday, the BBC cited a 2017 study by microbiologist Markus Egert of Germany’s Furtwangen University, reporting that kitchen sponges are a paradise for bacteria.
According to the study, 362 types of microorganisms were found in dish sponges. In some samples, up to 54 billion bacteria were detected per square centimeter. The warm, humid kitchen environment combined with food residue that clings to sponges during dishwashing creates an ideal setting for microbial growth.
Egert stated that the amount of bacteria found is comparable to that in human feces.
However, he also explained that the bacteria in sponges are not necessarily harmful to health. Bacteria exist in the air, soil, and virtually everywhere. The real issue is not the quantity of bacteria but whether they harm health.
Egert’s 2017 study found that in 5 out of 10 cases, the bacteria discovered in sponges were associated with those known to infect people with weakened immune systems. However, they were not linked to serious illnesses such as food poisoning.
According to Egert, only potentially pathogenic bacteria were found, meaning these microbes could pose a risk to people with weakened immune systems, such as the elderly or young children. He clarified that the bacteria in kitchen sponges are not harmful to generally healthy individuals. He also noted that of the five bacteria responsible for 90% of foodborne illness-related hospitalizations, three—E. coli, Salmonella, and Campylobacter—are rarely found in sponges.
Experts say most bacteria in sponges cause unpleasant odors rather than disease. As a precaution, they recommend thoroughly washing sponges after use and drying them as much as possible. Disinfecting sponges by boiling or using a microwave is also a recommended maintenance method.
In addition, experts advise replacing kitchen sponges every one to two weeks and emphasize the importance of maintaining overall kitchen hygiene.
