I just saw a fishy video of someone opening a can of tuna and putting the meat under a microscope.
It contained plastic microfibres.
Are these microfibres introduced at the factory which cans the tuna, or are do they actually come from the tuna meat directly? If the latter, then presumably no one is going around injecting microfibres into fish so they must come from the fishes diet. If so, then by the same mechanism, would I have microfibres in my muscle tissue?
I can understand having microfibres in my digestive tract, and even my lungs, but I would have thought it impossible to make it from my stomach to my meat.
For me the link goes to a very short instagram video-loop of a plastic fiber with what could possibly be tuna in the background, and a short description without any information about what steps this person took. I find it more likely the plastic fiber came from the microscopist’s clothing or the air. I don’t think there’s a reason to explore other pathways without documentation of the lab procedures used to prevent local contamination.
Okay I just double checked the link and it is not the same as the video I saw. Here it is on YouTube
The link I gave comes from the sources listed in the YouTube description.
But there doesn’t appear to be any way for the microfibres to get into the meat, right? I can’t see how they wouldn’t be confined to the digestive tract.
Polymer microfibers and microparticles are pervasive in the environment and particularly in aquatic environments where they are ingested by both microorganisms and larger animals. While these fibers are very small—often microscopic in size—they are still too large to pass whole through the digestive tract, and generally speaking are robust enough to survive passage through the digestive system. They are certainly not integrated into your muscles as this would result in inflammation and likely an allergic immune response. The fibers in the can of tuna undoubtedly come from the water it was packed in or incidental contamination from processing rather than from an intramuscular source, but they are essentially unavoidable.
However, there is considerable evidence that at least some of these materials, while generally structurally robust, can release bisphenol compounds (precursors to the manufacture of many polycarbonate plastics commonly found in packaging and reusable containers) which can interfere with hormone signaling. This is why you see Nalgene and similar ‘hydration bottles’ marketed as being ‘BpA-free’, even though they are still manufactured using other bisphenols which are suspected to have similar bioreactivity. Regardless, even if you are eating and drinking from all stainless steel or glassware, these materials are still in water supplies and can even be carried by wind and rain.
For the most part, ‘plastic’ is biologically inert; long-chain cross-linked polymers are too stable for animals to digest without specific enzymes to break them down, and despite the fact that ordinary sunlight causes most polymers to become embrittled they don’t actually break down into simple molecules or or atomic constituents without extreme heat or powerful solvents. The real problem is that plastic objects will break down into small (but structurally intact) particles, essentially an irreducible ‘dust’ of plastic, and that some types of plastic will outgas entrained precursors like the previously mentioned bisphenols, that are biologically reactive. This may end up being as much of a public health crisis as tetraethyl lead contamination and equally as persistent.