CLEANING A DIRTY SPONGE ONLY HELPS ITS WORST BACTERIA, STUDY SAYS

Stop. Drop the sponge and step away from the microwave.

That squishy cleaning apparatus is a microscopic universe, teeming with countless bacteria. Some people may think that microwaving a sponge kills its tiny residents, but they are only partly right. It may nuke the weak ones, but the strongest, smelliest and potentially pathogenic bacteria will survive.

Then, they will reproduce and occupy the vacant real estate of the dead. And your sponge will just be stinkier and nastier and you may come to regret having not just tossed it, suggests a study published last month in Scientific Reports.

By looking at the DNA and RNA in samples from 14 used sponges that may be as dirty as the one sitting in your sink right now, Markus Egert, a microbiologist at the University of Furtwangen in Germany, and his team identified 362 different species of bacteria living within them. And the scientists were surprised to find how densely microbes occupied such close quarters: About 82 billion bacteria were living in just a cubic inch of space.

The thrifty among us may try to clean a sponge that starts to stink, but it’s probably time to let it go every week or so.

But if you would rather not create that much waste, run it through a laundry machine at the hottest setting using a powder detergent and bleach and then use it somewhere other than the kitchen that is less hygiene-sensitive, like the bathroom.