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)
This does not say that and it's irresponsible to summarize it that way. That's a letter addressing a specific study from 2024 (which did record baseline levels because that's a standard experimental design step), arguing that it used an inadequate control so may have had background contamination when reporting the level of microplastics found in bottled water.
A "cohort of core studies" were not involved, and nothing was "judged to have invalid methodology". The study authors also replied, arguing that their choice of blanks was actually the better one: https://www.pnas.org/doi/10.1073/pnas.2415874121
There's been a slightly weird trend of people on HN that seem so eager to judge the microplastic story as overblown and unsupported that they're overstating and overextrapolating the smallest counter evidence into its own competing narrative, as if what we needed were more narratives. Resist this! That's not how good science or science communication is done.
I respectfully disagree, this was a commonly cited technique for measuring microplastics, which is why it calls into question many studies. Thanks for calling me weird :) I guess the suggestion though is I'm paid by big plastic or something, no infact I'm just a guy reading papers who is scared of death like everyone else.
> I respectfully disagree, this was a commonly cited technique for measuring microplastics, which is why it calls into question many studies.
What exactly was a commonly cited technique and where is this citation?
Regardless, you said "invalid methodology due to not recording baseline microplastic levels" when that was not the case and wasn't the letter's objection to the study's methodology.
> Thanks for calling me weird :) I guess the suggestion though is I'm paid by big plastic or something, no infact I'm just a guy reading papers who is scared of death like everyone else.
I said the trend was weird, but feel free to pick another adjective. Self contradictory, for instance. Sick of people overextrapolating from these "bombshell" microplastic papers, I will now overextrapolate from these "bombshell" methodological papers.
Look at the publications of the author of that letter and Cassandra Rauert, the lead author of the paper on detecting plastics in human blood that you linked below. Both of them have several publications on the almost universal contamination of the planet with microplastics and are clearly worried about the impact of this. Them insisting on and helping with better science from their colleagues is not laying the question to rest, it's a call to more rigorous action (literally[2]). It is scientific malpractice to call that "growing evidence that there is much less to worry about on microplastics".
I've heavily couched my language and not claimed authority. If you are looking for examples of irresponsible communication, look inward. You've mixed real quotes from me with ones you've injected ""bombshell"". I purposefully did not use such language. I get this is an issue that can emote, and I respect your view. Perhaps you've underestimated how much of your view I share.
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...)
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.
Actually this is the shocking part - it actually is enough to move the needle. Incidents of young people with cancer is small so a 100% increase can be driven by a small absolute number of patients. There has been an absolutely enormous increasing in high endurance sport something more like 20x (or 1900% increase) and ultramarathon/marathon runners are 7.5x more likely to get colon cancer, so this leads to a surprisingly large relative increase in colon cancer.
This does not say that and it's irresponsible to summarize it that way. That's a letter addressing a specific study from 2024 (which did record baseline levels because that's a standard experimental design step), arguing that it used an inadequate control so may have had background contamination when reporting the level of microplastics found in bottled water.
A "cohort of core studies" were not involved, and nothing was "judged to have invalid methodology". The study authors also replied, arguing that their choice of blanks was actually the better one: https://www.pnas.org/doi/10.1073/pnas.2415874121
There's been a slightly weird trend of people on HN that seem so eager to judge the microplastic story as overblown and unsupported that they're overstating and overextrapolating the smallest counter evidence into its own competing narrative, as if what we needed were more narratives. Resist this! That's not how good science or science communication is done.