Kitchen sponges contain more bacteria than kitchen brushes, which is probably a safer way to clean dishes, according to CNN, citing Applied Microbiology.
“Salmonella and other bacteria grow and live on sponges better than brushes, and the reason is that sponges as a result of daily use never dry out,” said Trond Moretro, a research scientist at a Norwegian institute specializing in food research.
He added that a single cleaning sponge “can harbor more bacteria than humans on Earth”, explaining that while many bacteria are harmless, those bacteria – like salmonella – can spread from sponge to hands, kitchen surfaces and appliances . It can make people sick.
He explained that “the sponge gets wet and collects food waste which is also food for bacteria, which leads to the rapid growth of bacteria.”
What surprised the researchers most about their findings, however, was that it did not matter much how users cleaned the sponge or how often they cleaned it. “The way consumers used the sponge does not matter much in terms of bacterial growth.” said Moretro.Growth of bacteria in the sponge as long as the sponge is not replaced daily.
The research on used sponges and brushes is based on a laboratory study published last year by the same team of researchers, which found that harmful bacteria live better in sponges than in brushes.
In the United States, the U.S. Department of Agriculture said sterilizing kitchen sponges by placing them in the microwave or in a pot of boiling water could reduce “some bacterial load,” but the study found that these methods alone are not enough for him. ensure the elimination of contamination in the sponge, so experts advise to buy new products often.
alternative for cleaning the sponge
The researchers collected kitchen sponges from 20 people living in Portugal and 35 brushes and 14 sponges from people living in Norway. A previous study of 9,966 people, conducted by the Norwegian team of researchers, had found that sponges are commonly used for cleaning kitchens in most European countries, while the use of the brush as a cleaning agent is widespread in only two countries, Norway and Denmark. .
All sponges were used for washing dishes, except for cleaning pots and pans, and 19 out of 20 sponges from Portugal were used five to six times a week or more. Of the brushes collected in Norway, 32 out of 35 brushes were used five to six times a week or more. And sponges collected in Norway were used less frequently.
No disease-causing bacteria were found on the brush or sponge. But bacterial levels were generally lower in the brushes used than the sponges. Likewise, non-pathogenic bacteria were found in the cleaning dishes.
Reducing the number of salmonella
When the researchers added salmonella bacteria to the brush and sponge, they found a significant reduction in the number of salmonella in the brush, due to its drying overnight. But the number of salmonella was not reduced on the brush stored in a plastic bag or sponge, regardless of storage conditions.
The owners of the sponges and brushes gave the researchers information on how long they used the sponge or brush normally and how they kept their cleaning products clean, whether by rinsing them with water, washing them with soap and water, setting them in the dishwasher or by bleaching.
It also turned out that all these methods did not produce any noticeable change, which surprised the researchers, who concluded that the main finding from the study is that the brush, which dries between each use, contains fewer bacteria.
“Because the brush dries very quickly, harmful bacteria die,” Moretro said. “Most types of kitchen cleaning brushes have gloves that prevent direct hand contact with potentially harmful bacteria, unlike sponges.” Moretro advised consumers to “try using a brush instead of a sponge”.
British and German scholars
While researchers recommended using a kitchen cleaning brush and removing sponges, Cath Reese, a professor of microbiology at the University of Nottingham who was not involved in the research, said she would continue to use sponges to wash dishes. explaining that in. at the same time she would be inclined to take advantage of the results that dry sponges and fabrics every day after use.
Professor Reiss explained her decision because, “The main message I got from the results of the study is that the researchers did not find any evidence of disease-causing bacteria in sponges or brushes taken from a group of household sites, and therefore there is no evidence that these elements are an important source of pollution in normal home environments.
As for the German scientist Marcus Eggert, a microbiologist at the University of Furtwangen in Germany, who did not participate in the study, but is personally inclined to use the brush to wash the dishes himself and then place it in the dishwasher. Use a new sponge every two to three weeks, explaining, “The brush is the best alternative for cleaning dishes, from a hygienic point of view. This may have been expected before, but researchers have proven this through some excellent experiments. But, based on my experience, many like to use sponge “, so discard the used sponge at most every 3 weeks.