When it comes to lurking dangers in your home, have you considered your rubber duckies lately? A 2018 study by the Swiss Federal Institute of Aquatic Science and Technology, ETH Zurich and the University of Illinois published in the Journal Biofilms and Microbiomes says you should. Scientists cut open toys used at bathtime, cultured them, and found almost all of them contained fungi and bacteria, included Legionella (which can cause a fatal pneumonia-like illness) and Pseudomonas aeruginosa (which can cause a host of problems, including skin rash and sores with sweet-smelling pus). The toys were so contaminated with a living film of germs, they could not be cleaned, except by boiling them. The scientists concluded that although children might benefit from a little challenge to the immune system, squirting bath toys into their faces should be discouraged because it’s too germy. Only toys that completely dry should be used in the tub! The filthy film can be found in places beyond the rubber duckies.

Cheap plastic such as PVC+ dirty water + soap grows a biofilm. Biofilms are easily detected as a slimy surface. According to Food Poisoning Bulletin, “Biofilm is a kind of slime made of protein that surround the bacteria, allow them to communicate with each other, and protect them from disinfectants. Biofilms are common in Reusable Plastic Containers (RPC). “What was striking about this study, the bacteria “not only attached to the RPC but could not be dislodged by either sanitizers or physical scrubbing.”

Plastic is not an easy to clean material. Biofilms can explain bacterial antibiotic resistance. They are gangs of bacteria. They are why you need to take your full dose of antibiotics. They are on slippery rocks. They are in your mouth as dental plaque. Yup, pretty much everywhere. Bacteria are pretty darn social.

Medical devices such as catheters pacemakers, IUDs, breast implants, and plastic heart valves can harbor biofilms. (Fortunately, antimicrobial plastics are now being used in these devices.) They can lurk under shampoo bottles left in the shower, and at the bottom of shower curtains, in your toilet bowl, in your humidifier, appearing as a pink ring or stain. What other household item regularly sits with water inside? Your garden hose! If soap dispensers are not cleaned regularly, yes, they will grow biofilms inside. The best way to avoid a biofilm in the house is to keep things dry and clean your sinks, showers, and toilets weekly. Keep bottles out of the shower when not in use. Regularly clean soap dispensers.

Biofilms can form on pool toys. If water puddles or soaks into anything plastic, the resulting bacteria can cause a rash or ear infections. Plastics used for pool fun should not be stacked but dried in the sun and disinfected with chlorine or other cleaners periodically. Biofilms can also be formed on decks if they don’t dry out!

Biofilms form on discarded plastic and microparticles of plastic in aqueous environments such as lakes and oceans. Tiny bits of plastic that harbor bacteria on the surface, the plastisphere, has been studied extensively. The particles can transmit disease, especially to aqueous animals, and encourage algae growth, although most of the plastisphere bacteria is not harmful.This is, however, another reason why plastic waste is such a problem in the oceans.

I’m tossing out old plastic bath toys and getting my bottles out of the shower. Hopefully, I will never see the dreaded “pink ring” of biofilm again.