Kitchen sponge to be replaced weeklyA common knowledge among microbiologists is that the things used to clean your dishes are the dirtiest objects in your home.

A recent study published in the Nature journal Scientific Reports says those spongy bacterial colonies are a health hazard. Thus it is best to replace the sponge every week.

In the new study, researchers did a genetic analysis of bacteria taking 28 samples from 14 used sponges. They wrote that this was the comprehensive analysis of the microbiome (the community of bacteria) living on kitchen sponges.

Generally, kitchens are the areas where new bacteria is introduced regularly and this is because of food preparation and human traffic. The sponges are wet, warm and contains old food traces that are ideal for bacteria as breeding grounds.

The new sponge analysis was done to see what lives on the sponges and not to find pathogens that makes people sick.

The kitchen sponges have the higher bacterial diversity. They also found five of the common bacterial groups had the potential.

The other surprising result was that the cleaning sponges may be less effective. On the other hand, Microwaving and boiling sponges can reduce initially about 60% of the bacteria, according to the study.

And even sponges were tested that was regularly cleaned in that way that it didn’t have less bacteria than the uncleaned sponges. The researchers believe that the bacteria may survive the sanitation process, but repopulate the sponge quickly, making it harder to remove those bacteria over time.

It is a good idea to clean a sponge after each use, suggest researchers and to replace sponge on weekly basis.