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"Just One Word: Microplastics"

Started by Recusant, December 22, 2021, 07:45:23 PM

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Dark Lightning

I just read about this! That's disgusting. This is probably how we end up trashing the planet (and dying), not global warming.

Tank

That's incredible and equally disturbing.
If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

Tank

Study shows how tiny plastic particles manage to breach the blood-brain barrier

QuotePublished in the journal Nanomaterials, the study was carried out in an animal model with oral administration of MNPs, in this case polystyrene, a widely-used plastic which is also found in food packaging. Led by Lukas Kenner (Department of Pathology at MedUni Vienna and Department of Laboratory Animal Pathology at Vetmeduni) and Oldamur Hollóczki (Department of Physical Chemistry, University of Debrecen, Hungary) the research team was able to determine that tiny polystyrene particles could be detected in the brain just two hours after ingestion.

More research. And no good news.
If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

MarcusA

#33
On human waste in general: it goes on. Life goes on but probably not for very  much longer at the rate that humans are laying waste to the planet, our home.
This user has been banned for spamming the forum.

Icarus

Quote from: MarcusA on April 24, 2023, 08:30:21 AMOn human waste in general: it goes on. Life goes on but probably not for very  much longer at the rate that humans are laying waste to the planet, our home.

One more hazard to add to the list. We have previously had only sparse information about "Nurdles".

https://getpocket.com/explore/item/nurdles-the-worst-toxic-waste-you-ve-probably-never-heard-of?utm_source=pocket-newtab

Dark Lightning

Yeah, I suspect that plastics are going to be our downfall before global warming. Sad, because that crap could take everything out that doesn't adapt to it.

Recusant

Apparently I've neglected to mention nurdles in this thread before, but as somebody who follows the topic, sadly I'm familiar with them. Probably they're a significant component of the North Pacific Garbage Patch. More macro than micro, but definitely relevant in this thread.

"Converging ocean currents bring floating life and garbage together" | Phys.org

QuoteThe North Pacific "Garbage Patch" is home to an abundance of floating sea creatures, as well as the plastic waste it has become famous for, according to a study by Rebecca Helm from Georgetown University, U.S., and colleagues. The paper is published in the open access journal PLOS Biology.

There are five main oceanic gyres—vortexes of water where multiple ocean currents meet—of which the North Pacific Subtropical Gyre (NPSG) is the largest. It is also known as the North Pacific "Garbage Patch," because converging ocean currents have concentrated large amounts of plastic waste there.

However, many floating ocean creatures, such as jellyfish (cnidarians), snails, barnacles and crustaceans, may also use currents to travel through the open ocean, but little is known about where they live.

The researchers took advantage of an 80-day long-distance swim through the NPSG in 2019 to investigate these floating lifeforms, by asking the sailing crew accompanying the expedition to collect samples of surface sea creatures and plastic waste. The expedition's route was planned using computer simulations of ocean surface currents to predict areas with high concentrations of marine debris.

The team collected daily samples of floating life and waste in the eastern NPSG, and found that sea creatures were more abundant inside the NPSG than on the periphery. The occurrence of plastic waste was positively correlated with the abundance of three groups of floating sea creatures: sea rafts (Velella sp), blue sea buttons (Porpita sp) and violet sea snails (Janthina sp).

[Continues . . .]

The paper is open access:

"High concentrations of floating neustonic life in the plastic-rich North Pacific Garbage Patch" | PLOS Biology

QuoteAbstract:

Floating life (obligate neuston) is a core component of the ocean surface food web. However, only 1 region of high neustonic abundance is known so far, the Sargasso Sea in the Subtropical North Atlantic gyre, where floating life provides critical habitat structure and ecosystem services.

Here, we hypothesize that floating life is also concentrated in other gyres with converging surface currents. To test this hypothesis, we collected samples through the eastern North Pacific Subtropical Gyre in the area of the North Pacific "Garbage Patch" (NPGP) known to accumulate floating anthropogenic debris.

We found that densities of floating life were higher inside the central NPGP than on its periphery and that there was a positive relationship between neuston abundance and plastic abundance for 3 out of 5 neuston taxa, Velella, Porpita, and Janthina. This work has implications for the ecology of subtropical oceanic gyre ecosystems.
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Recusant

Some positive-sounding news on this topic for once.

"Durable plastic pollution easily, cleanly degrades with new catalyst" | Northwestern University

QuoteMany people are familiar with the haunting images of wildlife — including sea turtles, dolphins and seals — tangled in abandoned fishing nets.

The main issue behind Nylon-6, the plastic inside these nets, carpet and clothing, is that it's too strong and durable to break down on its own. So, once it's in the environment, it lingers for thousands of years, littering waterways, breaking corals and strangling birds and sea life.

Now, Northwestern University chemists have developed a new catalyst that quickly, cleanly and completely breaks down Nylon-6 in a matter of minutes — without generating harmful byproducts. Even better: The process does not require toxic solvents, expensive materials or extreme conditions, making it practical for everyday applications.

[Continues . . .]

A pre-print of the paper is available:

"Catalyst Design to Address Nylon Plastics Recycling" | ChemRxiv

QuoteAbstract:

Rational tailoring of catalytic systems offers highly desirable transformations targeting the growing environmental challenges associated with plastics pollution. For example, the identification of efficient catalysts to address alarming end-of-life Nylon pollution remains underexplored.

Nylon-6 is a non-biodegradable high-performance engineering plastic with centuries of chemical persistence, resulting in millions of tons of waste accumulation. Here we report the rational manipulation of organolanthanide catalyst structure to achieve an exceptionally efficient, solventless, and scalable Nylon-6 depolymerization process, affording monomer ε-caprolactam in ≥99% yield.

Specifically, catalyst Cp*2LaCH(TMS)2 (Cp* = η5-C5Me5, TMS = SiMe3) operates at catalyst loadings as low as 0.2 mol% and temperatures as low as 220 °C. For efficient deconstruction of more recalcitrant commodity Nylon-6 end-of-life articles such as fishing nets, carpets, and clothing, the robust, thermally stable ansa-metallocene catalyst Me2SiCp''2YCH(TMS)2, (Cp'' = η5-C5Me4) effects >99% conversion of these items into ε-caprolactam.

The collected product can be readily re-polymerized to afford pristine Nylon-6 with higher molecular masses and comparable structural regularity, providing a superior upcycling pathway for end-of-life Nylon plastics. Experimental mechanistic studies reveal intriguing and effective depolymerization pathways, such as catalytic intrachain "unzipping" enabled by the catalyst π-ancillary ligand steric constraints. Effective interchain "hopping" mechanisms, as well as chain-end deactivation are also demonstrated and supported by DFT analyses.
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Tank

If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

Recusant

Microplastics infiltrating old lake sediments; no longer a good marker for the Age of Humans.

"Buried microplastics complicate efforts to define the Anthropocene" | Nature

QuoteThe presence of microplastics in layers of material that settle at the bottom of lakes might be an unreliable way to determine the onset of the Anthropocene — the geological epoch marking the consequences of human activity on the environment. That is the conclusion of researchers who have shown that tiny plastic particles can infiltrate deep into old sediments.

The date when the Anthropocene began is still being debated. But the presence of microplastics is one of the measures that geologists look at when analysing material from lakes and seas to see whether human activity has made an impact. And microplastic content has also been suggested as a way to date geological sediments.

In a study published [February 21] in Science Advances, researchers looked for plastics in sediment from three lakes in Latvia: Seksu, Pinku and Usmas.

They found 14 types of plastic in sediment samples. In all three of the lakes, the most recent, uppermost sediment layers contained the most plastic particles. But the team also found that smaller, narrower particles had travelled down into much older sediments that formed long before plastic production began in the 1950s. For example, particles of the biodegradable plastics polylactic acid (PLA) and polyhydroxybutyrate (PHB) were found in sediment that is more than 200 years old. The researchers used established techniques to date sediment samples, measuring the amounts of lead isotopes and spheroidal carbon-containing particles that the samples contained.

[Continues . . .]

The paper is open access:

"Downward migrating microplastics in lake sediments are a tricky indicator for the onset of the Anthropocene" | Science Advances

QuoteAbstract:

Plastics are a recent particulate material in Earth's history. Because of plastics persistence and wide-range presence, it has a great potential of being a global age marker and correlation tool between sedimentary profiles.

In this research, we query whether microplastics can be considered among the array of proxies to delimit the Anthropocene Epoch (starting from the year 1950 and above). We present a study of microplastics deposition history inferred from sediment profiles of lakes in northeastern Europe.

The sediments were dated with independent proxies from the present back to the first half of the 18th century. Regardless of the sediment layer age, microplastic particles were found throughout the cores in all sites. Depending on particles' aspect ratio, less elongated particles were found deeper, while more elongated particles and fibers have reduced mobility.

We conclude that interpretation of microplastics distribution in the studied sediment profiles is ambiguous and does not strictly indicate the beginning of the Anthropocene Epoch.
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Tank

If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

Icarus

This is an article about the cleanest air on earth.  Not unexpectedly, there are particles of plastic in the air, along with all sorts of other contaminants.

https://getpocket.com/explore/item/the-town-with-the-cleanest-air-in-the-world?utm_source=pocket-newtab-en-us