For the first time, microplastics have been found in human blood.

Microplastics can measure as small as 0.0007mm and researchers are worried that they might travel through people’s bodies and become lodged in their organs.

A study of 22 healthy people showed that 17 of them had microplastic particles in their blood. Half of the samples contained the kind of plastics used to make water bottles and one-quarter of the samples contained polyethylene plastic.

The study was funded by the Dutch National Organisation for Health Research and Development and an organization that fights plastic pollution called Common Seas.

One of the researchers, Professor Dick Vethaak of Vrije Universiteit Amsterdam in the Netherlands, said, “Our study is the first indication that we have polymer particles in our blood – ​it’s a breakthrough result. But we have to extend the research and increase the sample sizes, the number of polymers assessed, etc.”

Professor Vethaak added, “We also know in general that babies and young children are more vulnerable to chemical and particle exposure. That worries me a lot.”

Vethaak said that the research was “a breakthrough result” and added that more research needs to be done to find out how these microplastics may be affecting our bodies.