A team of scientists in the UK has discovered microplastics in the deepest part of the lungs, the finding the researchers say is unexpected and surprising.

Those responsible are scientists from the Hull York School of Medicine, and they say this study will help guide future studies of the impact of microplastics on respiratory health.

Study published in the journal Total Environmental Sciencefound 39 microplastics in 11 of 13 lung tissue samples analyzed: “This is the first robust study to show the presence of microplastics in the lungs of living people,” says Laura Sadofsky, lead author of the study.

“It also shows that they are in the lower parts of the lung. The airways in the lungs are very narrow, so no one thought they could get there, but it’s clear they have.”

Of the microplastics detected, there were 12 types that have many uses and are commonly found in packaging, bottles, clothing, string/fabrics, and many production processes.

In the statement made by the aforementioned school of Hull and York universities, it is also stated that the levels of microplastics are significantly higher in men than in women.

The study showed that 11 microplastics were found in the upper part of the lung, 7 in the middle and 21 in the lower lung, which was an unexpected finding.

“We didn’t expect to find the largest number of particles, or particles of the sizes we found, in the lower regions of the lungs.”

This is surprising, the researcher says, because the airways in the lower parts of the lungs are smaller, and particles of this size have to wait to be filtered or trapped before reaching this deep into the lungs.

It’s not the first time microplastics have been found in the human body. For example, last March, researchers at the Free University of Amsterdam (Vrije Universiteit) discovered that tiny bits of plastic from our living environment can be absorbed into the human bloodstream.