The Microplastics Alarmists

The findings should trigger alarm.

Such are the words of a scientist studying microplastics when he’s quoted in a press release from his university.

These data are associative and do not establish a causal role for such particles affecting health. For this, refinements to the analytical techniques, more complex study designs, and much larger cohorts are needed.

Such are the words when that same scientist is summarizing findings for other scientists.

We’re not talking about the now-debunked dangers of black plastic spatulas — a “danger” created by a math error that stated the safe level as 10x less than it really is. Fixing the math changed their finding from alarming to reassuring.

This source of alarm this time is the purported plastic spoon in your brain, and the scientist urging you to be alarmed is Matthew Campen of the University of New Mexico. His statement was made in the wake of a publication by his group in Nature Medicine on February 3, 2025.

The paper was covered widely, partially because Campen drew a parallel between the amount of plastic the researchers purported to find (~7g) and the weight of a plastic spoon (2-6g).

The image of a spoon inside your brain incited a media frenzy, one Campen helped to create and was only too happy to stoke with additional alarmism.

As you might expect since I’m covering it, the paper is beset with an array of problems:

• The paper was preprinted on Research Square (also a Springer Nature property) a week after it was submitted to Nature Medicine.
  • The preprint received more than 460 media mentions and 7,600 of downloads — before any peer-reviewed or corrected version was available.
• The preprint was indexed on PubMed, and its full text published on PubMed Central.
• The preprint is also available on ResearchGate.
• This preprint has not been updated despite substantial corrections to the published work.
• The uncorrected preprint is posted to NIH.gov for public access.
• Opportunism followed publication of the flawed paper:
  • First, with a splashy Nature News feature soon after
  • Then, with a “rising star” psychiatry resident from the University of Ottawa pushing a summary published afterwards
• A pretty substantial correction was issued on March 31, 2025, which included duplicate figures, errors in charts, errors in calculations, and just a litany of sloppy publication practices.

Fortunately for the scientists seeking attention, the echo chamber was assembled quickly, before the correction could come out.

The media coverage was noteworthy for a couple of reasons:

1. The consistent alarmism of the researchers who are clearly angling for attention and to justify further related grant funding.
2. The pictures in the New York Times showing a lab filled with plastics.

This last point gets to one of two major underlying problems with the study, as described well on the Science Vs. podcast this week:

1. The potential for microplastic contamination of necrotic brain tissue from the dissecting lab, from the various containers involved in storage, transport, and handling, and within the lab itself can’t be discounted.
   1. They may have been measuring dust, not physiological plastic residuals.
2. The methods used to detect the plastics involved burning the brain tissues and analyzing the smoke. The brain has a lot of fat in it, and burned fat can be easily mistaken for burned plastic residue.
   1. One wag noted that among the things he’d eat with the spoon in his brain would be his own brain — he hears the fat makes them creamy.

Maybe there’s something to the worries about microplastics. Maybe there’s not. We seem to excrete them pretty well based on studies of microplastics in our waste. There’s no clear physiological link to anything bad yet. It’s not like asbestos or lead paint, where it was pretty clear once scientists got involved that there was a problem. Even the methods and math seem immature at this point.

As the authors state:

These data are associative and do not establish a causal role for such particles affecting health.

But, of course:

The findings should trigger alarm.

What should trigger alarm in our community is how this paper was published, covered, corrected, reproduced, indexed, and allowed to confuse the scientific record.

That’s our bailiwick, and we are doing a terrible job these days.

Coming in the Spring of 2026