2. Young-onset cancers (especially colorectal cancer) which were inferred to be caused by a rise in microplastics are being linked explicitly to other mechanisms and cohorts. (https://ascopubs.org/doi/10.1200/JCO.2025.43.16_suppl.3619)
Can't read the full study, but it seems to be specifically about people who run ultramarathons. Which sounds like a very small subset of the general population. I doubt that tiny cohort is in any way responsible for the overall increase in bowel cancer in younger people.
I think those papers mostly show that parts of the microplastics literature were overstated or methodologically weak, not that microplastics are harmless.
The PNAS paper is a pretty good critique of contamination/baseline issues, and I agree some of the “microplastics are causing young-onset cancer” claims got ahead of the evidence.
But the broader concern still exists: people are clearly exposed constantly, particles are being found in human tissue, and there are plausible mechanisms for harm. So no, there is not "much less to worry".
I agree that there is not evidence to "not worry", but many explicit worries are being accounted for.
Also - in terms of human tissue:
"The problem is that some small molecules in the fumes derived from polyethylene and PVC can also be produced from fats in human tissue. Human samples are “digested” with chemicals to remove tissue before analysis, but if some remains the result can be false positives for MNPs. Rauert’s paper lists 18 studies that did not include consideration of the risk of such false positives." (https://www.theguardian.com/environment/2026/jan/13/micropla...)
Summary: dry contact with nearly any laboratory glove will lead to sample contamination and over estimation of microplastics.
They found one type of clean room gloves that contaminate less.
Is there any indication on how bad this really is?
Around 2000 to over 7000 false positives per mm^2 based on the type of glove. Essentially, regular lab gloves shed enough particles to swamp microplastic measurements to warrant switching to clean room gloves for this type of analysis.
It's difficult to avoid contamination, since everything (samples, containers, equipements, etc) will have been in contact with glove at least once, and good decontamination is very hard.
There is growing evidence that there is much less to worry about on microplastics on several fronts.
1. A whole cohort of core studies have been judged to have invalid methodology due to not recording baseline microplastic levels (https://www.pnas.org/doi/10.1073/pnas.2411099121)
2. Young-onset cancers (especially colorectal cancer) which were inferred to be caused by a rise in microplastics are being linked explicitly to other mechanisms and cohorts. (https://ascopubs.org/doi/10.1200/JCO.2025.43.16_suppl.3619)
"Exercise induced gastrointestinal injury"!
Can't read the full study, but it seems to be specifically about people who run ultramarathons. Which sounds like a very small subset of the general population. I doubt that tiny cohort is in any way responsible for the overall increase in bowel cancer in younger people.
I think those papers mostly show that parts of the microplastics literature were overstated or methodologically weak, not that microplastics are harmless.
The PNAS paper is a pretty good critique of contamination/baseline issues, and I agree some of the “microplastics are causing young-onset cancer” claims got ahead of the evidence.
But the broader concern still exists: people are clearly exposed constantly, particles are being found in human tissue, and there are plausible mechanisms for harm. So no, there is not "much less to worry".
I agree that there is not evidence to "not worry", but many explicit worries are being accounted for.
Also - in terms of human tissue:
"The problem is that some small molecules in the fumes derived from polyethylene and PVC can also be produced from fats in human tissue. Human samples are “digested” with chemicals to remove tissue before analysis, but if some remains the result can be false positives for MNPs. Rauert’s paper lists 18 studies that did not include consideration of the risk of such false positives." (https://www.theguardian.com/environment/2026/jan/13/micropla...)
and Rauert's paper (https://pubs.acs.org/doi/10.1021/acs.est.4c12599)
Summary: dry contact with nearly any laboratory glove will lead to sample contamination and over estimation of microplastics. They found one type of clean room gloves that contaminate less.
Is there any indication on how bad this really is?
Around 2000 to over 7000 false positives per mm^2 based on the type of glove. Essentially, regular lab gloves shed enough particles to swamp microplastic measurements to warrant switching to clean room gloves for this type of analysis.
Shouldn't any lab analysis have control samples to detect environment contamination like this?
It's difficult to avoid contamination, since everything (samples, containers, equipements, etc) will have been in contact with glove at least once, and good decontamination is very hard.
Now, I'm worried about people preparing my food with gloves.
“Are you wearing gloves? That’s disgusting. Use your bare hands, you animal.”
"I only allow robots with stainless steel tools to prepare and serve my food."