We know it's a chore to keep a kitchen clean, and if you use a sponge to wipe down kitchen surfaces and do dishes, you probably change it whenever it looks dirty. New research, however, says that might not be often enough.
German researchers studied the germs on sponges and found out they get so dirty they should be thrown out every week. They also found sponges hold on to more bacteria than any other object in a home, and usually have more bacteria than a toilet.
The study also showed that even sanitized sponges had high bacteria counts, so the researchers say the best thing to do is to invest in a new sponge every week.