[idDriven]

> The article says a "microplastic particle" is any peice of plastic smaller than 5mm

I double checked the article and you are right, this is why the use of the apothocary symbols are not used in medicine any more it should be "5 and 20 μm polystyrene micro-particles elicited somewhat similar pathological and physiological changes in mice. These, particularly the 5 μm micro-particles, could be detected in histological sections of the gut, liver and kidney." The symbol means micro or an order of a million times smaller than a gram/meter so the particulate size appears misstated and is actually an order of 1000 times smaller than a millimeter.

> This could easily be genuine epidemic levels of awful, or it could be completely nothing. Does anyone know more?

It has been shown microplastic contamination is very significant in plastic-bottled single-use drinking water. Avoiding exposure as much as possible is 100% best medical advice, avoid drinking from single-use plastic bottles whenever possible. An infographic from WHO: https://www.forbes.com/sites/niallmccarthy/2018/03/16/study-...

As for health effects microplastics definitely bioaccumulate in the gut, liver and kidneys in mice. Mice are not human but as this is a basic physiology issue it is very highly likely that they also bioaccumulate in humans. It is not clear whether humans or mice can ever clear these particles, it is likely they can damage these organs over time, they do cause biomarker and endocrine changes short term. This can indicate damage, possible scaring and a propensity to weight gain respectively. Also other unknown fun stuff. It is probably dose-dependent so if you avoid single use plastic bottled water thats key. The food supply issue (seafood) is less significant from a human health standpoint.

Second source:https://www.frontiersin.org/articles/10.3389/fenvs.2017.0006...

[mrob]

Microplastics were found in bottled water, but I see no evidence that they actually came from the bottles, and I can't think of any mechanism that could cause particles to break off from the insides of the bottle under normal storage conditions. It seems more likely that they were already present in the water when the bottles were filled.

[idDriven]

It's likely a result of the manufacturing process, at least partially. I found the journal article the WHO pulled data from. Heres the abstract (I italicized for emphasis):

Eleven globally sourced brands of bottled water, purchased in 19 locations in nine different countries, were tested for microplastic contamination using Nile Red tagging. Of the 259 total bottles processed, 93% showed some sign of microplastic contamination. After accounting for possible background (lab) contamination, an average of 10.4 microplastic particles >100 um in size per liter of bottled water processed were found. Fragments were the most common morphology (66%) followed by fibers. Half of these particles were confirmed to be polymeric in nature using FTIR spectroscopy with polypropylene being the most common polymer type (54%), which matches a common plastic used for the manufacture of bottle caps. A small fraction of particles (4%) showed the presence of industrial lubricants. While spectroscopic analysis of particles smaller than 100 um was not possible, the adsorption of the Nile Red dye indicates that these particles are most probably plastic. Including these smaller particles (6.5–100 um), an average of 325 microplastic particles per liter of bottled water was found. Microplastic contamination range of 0 to over 10,000 microplastic particles per liter with 95% of particles being between 6.5 and 100 um in size. Data suggests the contamination is at least partially coming from the packaging and/or the bottling process itself. Given the prevalence of the consumption of bottled water across the globe, the results of this study support the need for further studies on the impacts of micro- and nano- plastics on human health.

URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141690/

[smsm42]

That should be not so hard to check - some companies bottle water both in plastic and glass, levels can be compared. Others use specific sorts of plastics, so one could check if the particles in their water match the chemical composition of bottle plastic or contain other plastics that are not part of the bottle. Also, many companies supply water coolers which use big bottles made of different kind of plastics than retail water - but likely the water itself, from the same company, comes from the same manufacturing process. The profile of these can be compared and one can see if the bottles are the likely source.

[smsm42]

> Mice are not human but as this is a basic physiology issue it is very highly likely that they also bioaccumulate in humans

That would be rather easy to check - take a bunch of dead humans who likely consumed a lot of bottled water (i.e. pretty much any urban dweller) and check them for microplastics in certain organs. Has this kind of research already been done and if not, why not?

Also, "piece smaller than 5mm" can be a huge 4mm chunk of plastic or one molecule. Depending on that, the average of 325 particles per liter could be enormous or completely insignificant.

[idDriven]

Right? If you could just do a national sampling as part of routine autopsies or something it would give so much valuable data. Sadly there is a lot of politics and money even in scientific research now. I would really value this data, I don't know who would fund it though if not the government, likely not Nestle or a corporation with great sales of bottled water. Also please see my reply earlier in thread Smithsonian article shakes head in sadness said mm for particulate size when it should be 1000x smaller.