Where Are the Germs? (Not where you expect!)

Dannette Heeth, CEH, IP, AEMT-Paramedic
Certified COVID19 Tracer

Upon entry to a local store in my neighborhood, people are greeted with an employee holding a spray bottle of disinfectant who directs the patrons to the carts that have been disinfected.  I decided to put this to the test to see if the carts are without germs. 

By now, you have probably heard the term “ATP,” which stands for Adenosine Triphosphate. In simple terms, all organic material has ATP and every cell uses ATP for energy. ATP bioluminescence meters detect the amount of organic material on surfaces, but not the type of matter. The lower the ATP level, the cleaner the surface and less likely to harbor biofilm and pathogens. As a point of reference, in a healthcare environment, common touch surfaces should be under 10.

Before I went to the store, I washed my hands and swabbed for ATP, and the reading was 7. Upon return, the reading was 124 so I know that something I touched at the store was contaminated. The only surfaces I touched were the shopping cart, refrigerated cooler, a carton of milk and a bottle of Gatorade. Consulting with my colleagues, we determined that additional information was needed.  I repeated the process of washing my hands, taking a reading and returning to the store armed with ATP swabs.

First, I tested the handles of the shopping cart and the reading was 6. This means the store’s disinfecting processes are on target. Believing the bio-load was most likely on the refrigerated cooler handle, I tested that surface next. The reading was 7 so it was unlikely that was the contaminated surface. I was a bit perplexed. I had to have picked up the organic material from the store, but where?

Finally, I tested the only two products that I bought, milk and Gatorade. The milk container tested at 23; the Gatorade was 4,926! Most likely, this item had been recently stocked on the shelf over the last 12 hours and the person stocking the shelf had probably not washed their hands after using the restroom. (I sprayed and wiped the bottle with hydrogen peroxide and retested until it was a 0 reading.)

This proves the point that frequent hand washing is vital to community health. These days, it is not just a suggestion to keep hands clean, but a necessity.