Squeaky ducks a health risk In ducklings lurk millions of germs

Pathogens: Researchers find plenty of dangerous germs in rubber ducks

In many bathrooms, the colorful squeak duck may not be missing. Many a child does not like to get into the tub without the toy. But dangers lurk in the plastic animals. Researchers found in the bath toy tons of germs that can sometimes trigger dangerous infections.

Diverse bacterial cultures in ducklings

For many children they make bathing a pleasure: Little yellow ducks or even a poison green crocodile. In a recent investigation, however, has shown that the bath toy is often full of dangerous germs. The researchers from Switzerland and the USA found fungi and bacteria in the plastic toys, which could cause partial ear, eye and intestinal infections in the children. In addition to the plastic material, the bathers themselves contribute to the fact that a variety of bacterial cultures can grow up in the ducklings.

Researchers have found millions of germs in rubber ducks. The fungi and bacteria could cause partial ear, eye and intestinal infections in children. (Image: Claudia Marx / fotolia.com)

Children often inject brown broth into their faces

In bathrooms, it is usually warm and humid. These are ideal conditions for the growth of biofilms from bacteria and fungi, for example on shower curtains or behind small boxes.

But this is especially true for rubber duckies and other toys used in bathing. Because inside the soft animals, lush carpets of bacteria and fungi can grow.

When a child squeezes his toy together, a brown broth often spurts out.

Now, a group of researchers from Eawag (Swiss Federal Institute for Water, Wastewater Treatment and Water Protection), the Swiss Federal Institute of Technology (ETH) Zurich and the Illinois University (USA) has investigated which factors promote this growth and which types of microorganisms are involved.

The results were recently published in the journal "NPJ Biofilms and Microbiomes".

Potentially pathogenic bacteria in 80 percent of the ducklings

The scientists have collected bath toys and used them to characterize biofilms from bacteria and fungi on the inside, reports Eawag in a statement.

At the same time, tests were also carried out with new rubber ducks. For eleven weeks, the researchers exposed them to conditions that would be realistic in a household - some as a control group only in clean drinking water and some in the bath water used, including factors such as soap residue, dirt and sweat, but also bacteria in the human body.

Subsequently, all ducks were cut open in the laboratory and examined. "The results do not sound appetizing," says the statement. Between five million and 75 million cells per square centimeter caved on the plastic surfaces.

Especially in baths used under real conditions, but also between control groups, there were major differences in the composition of biofilm communities.

On 60 percent of the real used and on all used in dirty water control ducklings were various fungi.

In 80 percent of all ducklings, the researchers found representatives of potentially pathogenic bacteria, including legionella or the rodent bacteria known as persistent hospital germs Pseudomonas aeruginosa.

Even bathers bring dirt into the tub

Then the scientists investigated the causes of the lush biofilms: First, they examined the tap water. This usually has such low nutrient concentrations that bacteria can only grow minimally.

But the ducklings themselves provide a source of nutrients. Because of the soft plastic material - often poor quality polymers - much organic carbon is released.

When bathing other important nutrients such as nitrogen and phosphorus, but also get additional bacteria in the tub, for example, from the body of the bathers, brought along dirt or toiletries such as shampoos and creams.

Dangerous pollutants

In this country too, in the past, partly unauthorized high levels of various pollutants have been found in water toys such as rubber ducks.

For example, TÜV Rheinland reported discoveries of so-called phthalate plasticizers, which, according to the experts, are suspected to be "hormonal and carcinogenic.".

In addition, some products contained too high levels of toxic polycyclic aromatic hydrocarbons (PAHs), which are also suspected of causing cancer.

Germs can cause inflammation and infections

The main author of the current study, the microbiologist Lisa Neu, addresses in her doctoral thesis - not only the example of rubber ducklings - how plastic forms biofilms and how the materials influence microbial processes in drinking water.

Her supervisor, Frederik Hammes, is not surprised at the results: "There are many forums and blogs about dirty ducks on the internet, but so far they have hardly been scientifically investigated."

The toys are extremely exciting research objects, "because they form the interface between drinking water, plastics, external pollution and vulnerable end users," said Hammes.

With the vulnerable or sensitive users, the expert addresses the (small) children, who like to splash with the broth from the ducklings.

"That can strengthen the immune system. Then it's positive, "says the researcher," but it can also lead to inflammation of the eyes and ears or gastrointestinal infections. "

Stricter regulations

So better no more bathing in the tub? After each use lavishly clean? Or, as recommended on the internet, even before the first use of the spray fun and prevent sticking the hole?

Hammes sees yet another way: tighter regulations for the polymers used for the ducklings.

This also worked for problematic chemicals. Now, one would have to take into account the release of carbon, as it is already done today in the tests for plastic drinking water pipes. (Ad)