invariant invertebrate inveigh

Over fifty years of data show a peak in PFAS (also known as "forever chemicals") content in seabird eggs in the 90s, followed by a decrease as regulations went into effect. The most recent findings show a 70% decrease of most common PFAS.

We are making genuine progress! Producers are dramatically altering how much they use PFAS and how much gets released in effluent, but also there's a lot better understanding of how to remove PFAS from the environment!

you can think of this sort of like how water wicks into a paper towel. the water gets stuck to the paper because it's attracted to it via capillary forces, even though there's no chemical reaction going on.

the two main methods used are granular activated carbon (GAC) adsorption and ion exchange (IX).

activated carbon is already pretty familiar to a lot of us; it's the stuff in a lot of replaceable water filters. the activated carbon has a huge internal surface area, and that allows for the fairly weak intermolecular forces to add up and allow contaminants to get "stuck" onto the surface of the activated carbon. over time, the activated carbon gets filled with junk, and you have to replace it.

GAC is essentially this, except that the activated carbon is granularized and produced in specific ways to maximize how much it attracts certain chemicals. this can be tuned because activated carbon gets its massive surface area from internal "pores", and various processes will change how large and frequent those pores are.

It's essentially a Russian nesting doll of pores, and controlling the size of the larger pores influences the permeability of the activated carbon and controlling the size of the smaller pores (micropores) influences what exactly is most attracted to the activated carbon.

However, GAC has a few major downsides:

It is not specific to PFAS. This is more of a mixed blessing because it was already frequently used and well understood, and the infrastructure for producing and distributing it already existed. However,

It loses effectiveness over time and must be replaced. This is a continued cost, albeit a low one, but this has one final major issue

As time goes on, the PFAS previously adsorbed to the activated carbon is desorbed and replaced by other things that have a higher affinity for the activated carbon.

As such, ion exchange (IX) was always very compelling. The whole point of it relies on the fact that PFAS molecules are predominantly made of two parts: An acid head group (either a carboxylic or sulfonic acid group) and a perfluorinated tail.

The head groups on the right are what become ionized—or specifically, deprotonated. A hydrogen leaves and is replaced with a metal cation (usually sodium), forming a PFAS salt (chemical meaning of salt!). These are much more soluble in water because of polarity reasons, and so the mobile PFAS molecules are almost always in that salt form.

By passing through these PFAS salts through a permeable polymer matrix that has (1) numerous positively charged groups like quaternary amines and (2) highly mobile negative ions loosely attached to those stationary positive groups (most often chlorides), you can actually get the PFAS to be "stuck" inside the polymer matrix and what comes out is just good ol' sodium chloride, or salt (culinary meaning of salt!).

This shows a version with hydroxide (OH-) ions as the mobile anion, but it's the same idea. The +NR3 in yellow are stuck to the polymer matrix, but the OH- can freely move around. However, without another anion to replace the OH-, the ionic attraction prevents the hydroxides from leaving.

In comes the PFAS. Despite being slightly soluble in water, the anionic PFAS aren't really that mobile, and when they pass through, it's much easier for the hydroxide ions to leave. Another very important effect is that the long perfluorinated tail of the PFAS is attracted to the polymer matrix, whilst the counterions are ONLY attracted via the ionic force. Thus, PFAS would much rather hang out in the polymer matrix.

Of course, IX has its own downsides

These resins are much more expensive, both to manufacture and to transport.

While they can be "regenerated", it's a tricky process that currently requires the use of nearly anhydrous methanol, which is both poisonous and extremely flammable, increasing the operating costs.

As the hydrophobic tail is a key part of allowing the PFAS to stick to the matrix, short-chain PFAS are very poorly dealt with by this system. This is exacerbated by competition between different PFAS molecules, as long-chain ones will cause short-chain ones to desorb.

Overall, the best method appears to be using a series of ion exchange resins followed by an activated carbon filter. The ion exchange will capture the bulk of the PFAS molecules, and the activated carbon will grab any stragglers. Effective filtering of other contaminants prior to the PFAS removal system will also ensure minimal competition in the activated carbon.

Okay good. Now go outside and try to garden. I need you to become rapidly disillusioned with it. Like you just don't find it enjoyable at all. The sun is too hot, or it's too cold, It takes consistency you don't really have time for, you're hungry, you don't have time to shower and make it to work, you --yeah I know gardening is hard and it's hard to do it. That needs to be your main takeaway! A sense of a nonspecific wound-- oh shit sorry, yeah I'll cover my mouth when I cough where are the fucking napkins.

In 2017, American film researchers recovered “Something Good – Negro Kiss,” a short film depicting a playful kiss between a Black couple which had not seen the light of day for more than a century. A long-forgotten artifact from the earliest years of American film, the sweet, humanizing vignette, produced by the Selig Polyscope Company, makes a startling contrast to the overwhelmingly racist and blackface-ridden contempory portrayals of African Americans. Four years later in 2021, archivists in Norway, halfway across the world, identified a sister short in their collections—an extended alternate cut which reveals more of Chicago stage performers Gertie Brown and Saint Suttle’s vaudeville-like routine, a theatrical, hot-and-cold romantic dynamic between two lovers which parodies the popular and controversial short “The Kiss” (1896). Both films, which had previously been lost, were known from entries in old motion picture catalogs but had been assumed to be era-typical, anti-Black “race films” until their rediscovery in the 21st century. Together with its more famous sibling, which has since been inducted into the Library of Congress’ National Film Registry, this alternate version of “Something Good” represents the first-known instance of Black intimacy ever captured on-screen.

It can almost certainly tell different species apart based on the shape of those air bladders. And it can tell if a fish has something weird inside it, like a metal hook. In Hawaii, false killer whales often pluck tuna off fishing lines, and “they’ll know where the hook is inside that fish,” Aude Pacini, who studies these animals, tells me. “They can ‘see’ things that you and I would never consider unless we had an X-ray machine or an MRI scanner.”

This penetrating perception is so unusual that scientists have barely begun to consider its implications. The beaked whales, for example, are odontocetes that look dolphin-esque on the outside—but on the inside, their skulls bear a strange assortment of crests, ridges, and bumps, many of which are only found in males.

Pavel Gol’din has suggested that these structures might be the equivalent of deer antlers—showy ornaments that are used to attract mates. Such ornaments would normally protrude from the body in a visible and conspicuous way, but that’s unnecessary for animals that are living medical scanners.’

I'm not sure if I ever shared this story before here, but in Curacao, when I was allowed to assist in a guest interaction programme, there was suddenly consternation in the pool behind us. A guest had entered the water and the dolphins were going crazy, paying no heed to the trainers anymore. The lead trainer that was with me gave the dolphins to me to watch over while she went to help. When she came back she told me what had happened. The guest that had caused so much uproar had left the water again and was asked if he had done anything to upset the dolphins. He hadn't, and he couldn't imagine what was wrong... until he mentioned he had a pacemaker. The younger dolphins in the pool had never seen someone with a pacemaker before and apparently it rocked their world.

Over fifty years of data show a peak in PFAS (also known as "forever chemicals") content in seabird eggs in the 90s, followed by a decrease as regulations went into effect. The most recent findings show a 70% decrease of most common PFAS.

We are making genuine progress! Producers are dramatically altering how much they use PFAS and how much gets released in effluent, but also there's a lot better understanding of how to remove PFAS from the environment!

An interesting game where you are presented with 10 artifacts from the MET. You have to place where the artifact is from and what time period it is from. Each artifact scores up to 10,000 points, and you lose points the further away your guess is and how far off in time you are. You can only play once a day. Thanks to @baebeylik for showing this to me.

Today I scored really well. Yesterday ... not so much.