Kitchen sponges have long been thought to harbor loads of germs. But new findings published in the journal Scientific Reports suggest that they carry much more bacteria than previously imagined, even more than are found in toilets, reports CBS News.
For the study, German researchers examined 28 samples from 14 different used sponges collected from various places in the home to determine how much bacteria they contained. In particular, scientists checked for the following: which types of germs the sponges harbored, where in the home the bacteria originated, where on the surfaces of the kitchen sponges the pathogens were distributed and which factors influenced the composition of their bacterial environment.
Researchers tested individual sponges for variables called intrinsic factors, such as the germs contained on their top and bottom parts and on branded versus non-branded products. In addition, scientists checked variables termed extrinsic factors, such as the number of sponge users in the household, frequency with which the sponges were used and replaced and any special procedures that were used to clean them, including heating sponges in a microwave and rinsing them with hot, soapy water.
Findings showed that the sponges contained 362 different types of bacteria. What’s more, researchers found that five of the 10 most abundant kinds of germs were closely related to ones that could possibly cause disease in humans. Scientists also noted that methods commonly used to sanitize sponges weren’t as effective as once believed. (Although microwaving and boiling sponges reduce bacteria by 60 percent, these germ-killing techniques worked best in laboratory settings.)
Despite the results of the study, some experts stressed that there’s no cause for alarm, since “bacteria are everywhere.” In addition, scientists noticed that newly purchased sponges were practically bacteria-free, so they advised simply replacing sponges each week.
Click here to read about how washing your hands with cold water can kill bacteria.