How often do you replace your sponge? Every fortnight? When it looks grubby? A new study in Scientific Reports says you should be chucking that germ haven out every week.
“Our work demonstrated that kitchen sponges harbor a higher bacterial diversity than previously thought,” say the study authors. “We therefore rather suggest a regular (and easily affordable) replacement of kitchen sponges, for example, on a weekly basis.”
“Our study stresses and visualizes the role of kitchen sponges as microbiological hot spots in the built environment, with the capability to collect and spread bacteria with a probable pathogenic potential.” Yeah, chuck that gross sponge in the bin, like, right now.
While your toilet might be your biggest concern, this study found the humble kitchen sponge should really be our target. “Despite common misconception, it was demonstrated that kitchen environments host more microbes than toilets. This was mainly due to the contribution of kitchen sponges, which were proven to represent the biggest reservoirs of active bacteria in the whole house.” We repeat – the most bacteria in the whole house.
FYI: if you’ve been boiling or microwaving your sponge to sanitise it, this can make it worse. Their studies found the sanitized sponges “increased the relative abundance” of both the Moraxella and Chryseobacterium species. Authors believe resistant bacteria survive the sanitation process and rapidly recolonize the sponge, similar to the effect of antibiotics on the gut microbiome.
Using tea towels and just chucking them in the washing machine? Err, think again. The authors point out that bacteria can survive most washes and can actually be enriched in the domestic washing process. BRB, off to buy every sponge in the supermarket.