AyanamiKaine
33 minutes ago
Microplastics have always fascinated me, because I keep seeing article after article about how much microplastic exists around us, but far less strong evidence about its actual effects. That is not to say there are no effects, of course. Maybe we just have not found them yet.
A friend of mine worked on her bachelor’s thesis about the effects of microplastics on the immune system, specifically T cells. Her result was that the microplastic particles she studied were too large to interact with T cells.
She probably will not publish this result because she thinks it is not interesting enough. Classic file-drawer problem in academic science.
While I encourage her to do it anyways as a negative results is also interesting but she wanted results that are worthing of headlines in magazines.
magicalist
4 minutes ago
> Her result was that the microplastic particles she studied were too large to interact with T cells.
Her "result" of what? Was there an actual experiment and what was it's scope or was this by surveying literature?
Microplastics are of a pretty large range of size, and then there are nanoplastics below that.
I'm also not an expert, but a quick search shows a number of results of microplastics affecting T cells, some directly and some in terms of immune signaling, so this negative result doesn't seem that definitive.
(as usual, the difficulty is in teasing out in vivo effects)
legitster
13 minutes ago
> She probably will not publish this result because she thinks it is not interesting enough. Classic file-drawer problem in academic science.
It's truly insane that everyone in the academic class understands the fundamental problems of herding and sampling bias and yet every incentive is in place to do this.
schiffern
6 minutes ago
I expect many researchers are using fresh lab-made microplastics, which are indeed mostly harmless. However part of the problem is that real-world plastics are chemical sponges that absorb toxins (heavy metals, PCBs, etc) from the environment and deliver them in a concentrated dose into the body.
app13
30 minutes ago
I participated in research from 2017-2022 that found similar results regarding bio-interactions, generally.
Learned a lot about making microfludic flow cells at least
jagged-chisel
20 minutes ago
> ... too large to interact with T cells.
Also, unfortunately, a result that industry and the anti-regulation crowd will use to say microplastics are harmless.
codybontecou
25 minutes ago
Can microplastics never get small enough to interact with T cells?
Retric
15 minutes ago
There’s a transition point where things stop being micro plastics and become chemicals. Those molecules may be toxic but the interactions are distinct from microplastics.
tristor
10 minutes ago
Unknown to me, but something useful to know is that there is something smaller than microplastics called nanoplastics. The distinguishing factor is that nanoplastics are particles smaller than 1 micron, while microplastics are particles between 1 micron and around 5 millimeters. As your other respondent notes, at some point you're talking about single molecules. As plastics is an entire category and not a single thing, there's no one size where that happens, but some polymers have chains that are as little as 0.01 (1/100th of a) micron in size.
As far as I am aware, we have yet to have effective, replicable research on what if any biointeractions exist with nanoplastic particles, including single polymer chains.