Researchers fire back after scientist calls monumental studies into question: 'The science is absolutely clear'

Scientists are debating the finer details of microplastics in the human body, according to The Washington Post.

What's happening?

It's often said that microplastics are everywhere, including in the environment and in living things, and an ever-growing body of research increasingly attests to their ubiquity as a contaminant.

On Jan. 13, the Guardian published an article about one researcher's objections to the structure of one study on microplastics and the human brain. 

Dr. Dušan Materić is considered an expert in the field. In its article, the Guardian cited a February 2025 LinkedIn post in which he described a then-recently published Nature Medicine study about microplastics and the human brain as "a joke."

Materić was one of several authors who challenged the study formally in Nature's Matters Arising, a section for trailing peer-reviewed discourse on published studies.

The Post maintained Materić argued that "'more than half of the very high impact papers' in the field [had] serious doubts associated with them," eliding a detail from the Guardian's reporting. 

It stated that Materić "thinks there are serious doubts over 'more than half of the very high impact papers' reporting microplastics in biological tissue," specifically, not that he challenged "more than half" of the studies "in the field."

Why is this concerning?

Microplastics began accumulating after plastic became a major part of the supply chain, but they weren't formally identified until 2004.

It's not necessary to be a credentialed researcher to observe that the gap between the introduction of plastic in the aftermath of World War II and the discovery of microplastics hinted at a sneaky, insidious contaminant.

To wit, microplastics have continued to build up in the air, water, and soil for decades, escaping the notice of scientists and researchers, making them inherently difficult to find, much less study.

How concerned are you about microplastics in your body? Orlando Bloom level 😥 Somewhat 🤔 I don't know enough 🤷 Not at all 🙅 Click your choice to see results and speak your mind.

The Post noted that the Guardian's microplastics piece coincided with a gathering of "hundreds of scientists studying microplastics" in Santa Fe, New Mexico, many of whom commented on the alleged ambiguity in the field versus a vast "body of evidence."

"The body of evidence across all organisms supports that micro- and nanoplastics are accumulating in animals and humans. We might not have all the details boiled down yet, but that's not disputable," ecotoxicologist Susanne Brander clarified, per the Post.

Australia-based ecotoxicologist and developmental pediatrician Christos Symeonides agreed.

"The science is absolutely clear: We are exposed to micro- and nanoplastics every day through the air we breathe and the food we eat. What we don't know is how much micro- and nanoplastic gets through the linings of our lungs and gut and into our body," he wrote, per the Post.

What's being done about it?

As Symeonides explained, Materić's formal challenge was "exactly how science works in tackling a new problem" and a critical part of the process.

Materić did not respond to the Post's requests for comment.

Researchers emphasized that avoiding exposure by using less plastic was one way individuals could mitigate microplastic risks.

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