What do the following situations have in common?
- A woman places her purse on the floor and then later picks it up.
- A man drops his pen on the floor and picks it up.
- A custodial worker gathers a vacuum cleaner cord.
- A student bends down to tie his shoestrings, which have been dragging on the floor.
One common denominator among all these situations is obvious: each scenario involves a person touching something that has touched the floor. What isn't so obvious is that there is something else on those floors--something that goes unnoticed even though it is both common and dangerous. Floors are actually hotbeds of contaminants, and studies indicate we have as many as 50 direct and indirect contacts with floors every day.
The near-constant presence of contaminants on floors has been verified in numerous studies, most conclusively by Dr. Charles Gerba in a report published in 2008. That report, which investigated germs and microbes collected on ten pairs of new footwear worn over a two week period, found that more than 420,000 units of bacteria were present on the shoes after the test period. Some of the bacteria found included:
- Escherichia coli, known to cause intestinal and urinary tract infections
- Diarrheal diseases
- Klebsiella pneumonia, a common source of wound and bloodstream infections as well as pneumonia
- Serratia ficaria, a rare cause of infections in both the respiratory tract and wounds
'The common occurrence of coliform and E. coli bacteria on the shoes [present in 96 percent of samples taken from the shoes] indicates frequent contact with fecal material, which [often] originates from floors in public restrooms,' says Gerba. 'The study also shows that bacteria can be tracked by shoes over long distances onto other floors [after they are] contaminated with bacteria.'
Most strikingly, Gerba found that the transfer rate of bacteria from shoes to uncontaminated tiles ranged from 90 percent to 99 percent. This means that when we have contact with floors, even through such indirect contact as picking up a fallen pen, there is a good chance that we will come into contact with a variety of contaminants, beginning the spread of cross contamination.
Mop the Problem Away?
The first suggestion many facility managers may have to stop the spread of floor-based contaminants is to simply mop them away, using ever more powerful disinfectants and cleaning chemicals. However, while this tactic is often the first line of defense, it may not prove successful.
A study published by the University of Ottawa, Canada, dating all the way back to 1971 actually identified floor mopping practices as being responsible for 'significant contamination of floor surfaces.' Their survey of hospital floors before and after mopping showed that 'these [mopping] cleaning procedures were in fact spreading gross contamination throughout the hospital.'
At the time of this study, researchers could offer few suggestions regarding how to minimize cross contamination other than to use more powerful cleaning chemicals and to change mops and buckets frequently. Forty years later, however, another hospital found an effective alternative.
Women's and Children's Hospital in Charleston, WV, essentially stopped mopping many of their floors a number of years ago because of concerns about the spread of contamination. They also minimized the use of sprayers and cleaning cloths for the same reason.
According to Donald Hammons, Housekeeping Services Manager at the hospital, conventional cleaning methods that can spread disease have been replaced in his facilities with the No-Touch Cleaning system developed by Kaivac. The hospital's multiple Kaivac systems apply cleaning solution to floors, walls, and other areas to be cleaned. The same areas are then rinsed with clean water, which loosens and removes germs from surfaces; those contaminants are then vacuumed up and totally removed.
'We found the [Kaivac] to be much more thorough than using traditional cleaning tools,' says Hammons. 'But what is most important, we have found a way to effectively remove ? not spread ? contaminants from our hospital floors.'