Conclusion

My hypothesis that the sponge would retain the least bacteria was correct. The dish mops retained the most bacteria, then the dishcloth, and then the sponges. The dish mops and the dishcloths had the largest surface area and stayed moist longer than the sponges. The sponges were porous and dried faster and had the least surface area. Bacteria grow fastest in warm, moist environments. The folded dishcloths and dish mops provided a warmer and moister environment than sponges.

There was also a definite difference between the antimicrobial sponges and the regular sponges. Antimicrobial sponges were treated with special chemicals that resist the growth of bacteria on the sponge fibers. The antimicrobial had much less bacterial growth than the regular sponges, especially after storage for 48 hours.

There was also a difference in the amount of bacteria present depending on the rinsing method. The most bacteria were present after rinsing with only boiled water. The least amount of bacteria were present when the used materials were rinsed with a 5% bleach solution. Rinsing with soapy tap water gave much better results than plain boiled water but was definetely not as effective as using bleach to reduce the amount of bacteria present.

All of the cleaning materials had much more bacteria present after being stored for 48 hours. The storage of the already moist cleaning materials at room temperature for 48 hours encouraged bacterial growth. The dishcloths and dish mops which had a larger area to trap food particles in had much more bacteria present after storage.

I would conclude that although it is definitely necessary to clean our dishes, we should pay closer attention to what we clean them with, how we rinse the materials we clean them with, and how long we keep using the same materials over again. I would reccomend the use of antimicrobial sponges that are rinsed with a bleach solution and changed frequently (for example weekly ). I plan on using our dishwasher more often!