Scientists in Austria say they've detected tiny bits of plastic in people's stool for the first time, but experts caution the study is too small and premature to draw any credible conclusion

Presenting their findings at a congress in Vienna on Tuesday, researchers from the Medical University of Vienna and the Environment Agency Austria said their pilot study detected nine types of so-called microplastic in all samples taken from eight volunteers living in Europe, Russia and Japan

While the study's authors did not know how the plastic got there, food diaries kept by the volunteers show they had all consumed food wrapped in plastic or drunk from plastic bottles during the week before the samples were taken, and six of them had consumed sea fish.

Tiny bits of plastics

Microplastics-defined as pieces smaller than five millimeters-have previously been found in water, animals, and food, but so far studies have not proved they pose a risk to human health.

Still, there is growing public concern about their apparent ubiquitous presence in the environment, and the head of Germany's Green party said the Austrian study was "a further alarm signal."

Robert Habeck told the Funke media group that microplastics should be banned from cosmetic products and the use of plastic packaging should be greatly reduced.

However, experts say that it would not be surprising that microplastics would be found in human samples too, and that the Austrian study raises many questions.

"It's small-scale and not at all representative, "said Martin Wagner, a biologist at the Norwegian University of Science and Technology. the study was not reviewed by independent scientists, and the authors did not provide details about which measures were taken to prevent samples from becoming contaminated.

Even if microplastics are the stool, this does not mean they have entered the human body, he said. Other, other substances we eat, microplastics are to be absorbed by cells in the gut and simply pass through.

Concerns were echoed by Mark Browne, an expert on microplastics at the University of New South Wales, Australia, who said the study lacked crucial details.

"Poor quality observations of contamination do not represent well the scientific method and therefore in my humble opinion do not help us understand human beings or manage them," Browne told the AP by email.

The Austrian authors acknowledged that "further studies are necessary to assess the potential risk of microplastic for humans." They plan to submit to detailed study for independent review in the coming months.