The Marsupial Perspective

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.

Also a welcome reminder that just because a Big Problem doesn't seem practically solvable right now doesn't mean it won't become solvable in the future!

(fengyoujing风油精, literally wind oil essential, like tiger balm, it’s a daily household item in China. The light green liquid has a strong refreshing scent. Dab it on your temples and neck in summer to stay awake. It relieves itching and swelling from bug bites, especially mosquito bites, and eases dizziness and mild car sickness too.)(cr国家特级铲shi官)

Take a moment and ask yourself, a project like this requires a lot of time, money and dedication of resources, why would scientists dedicate that time to something that could just be done by a tree?

The answer is they wouldn't. So that means this claim requires further investigation!

This project is called LIQUID 3, and it's not meant for cities with wide open spaces, it's meant for cities like Belgrade in Serbia. These cities are densely populated and heavily polluted, to the point where pollution actually chokes out current trees and makes creating green spaces difficult.

Liquid 3 was a PhD scientists answer to these problems. The microalgae tank is intended for spaces where you either:

Don't have enough space to plant full trees, or

Don't have enough time to plant trees and wait for them to grow up.

The tank is extremely efficient when you consider the amount of space needed compared to the amount of CO2 turned into oxygen. The tank can operate throughout the winter. And most importantly, it can be quickly set up in areas that desperately need relief from air pollution NOW not in 10 years when trees are done growing. Children currently suffocating on polluted air can't wait for trees to grow, they need to be taken care of now, and Liquid 3 is one of the ways to take care of them. Depending on the species of microalgea used, a number have shown a pretty amazing capacity to pull heavy metals out of the air which is something trees can get choked up by.

The tanks aren't just tanks either! Liquid 3 have solar panels placed on top, they have lighting and mobile phone charging, and they work as public benches. The designers of it want to encourage green spaces where there's room, but where there isn't room or time, Liquid 3 can step in. Realistically, this isn't a replacement for trees. It's replacing boring metal city benches with new, cooler benches that also clean the air (and have at least some heating during the winter).

Not only that, but the microalgea that grows is native to Serbia and all that microalgea has a ton of great uses! It makes for great fertilizer, compost, wastewater treatment, cleaner biofuels and even for helping create new tanks for further air purification. They only require a quick algae divide once a month, and the produced algae can be carted off to where ever it's needed. This makes them effective solutions for areas that can't sustain complex installations.

I've gone. Not one for goodbyes, I thought it best to slip out quietly. Love to you all, Giles.

Medications can make those thoughts go away. Specifically for SSRIs, we target higher doses, like "max" recommended dose, or even above, like at least 20mg of Lexapro or 60-80mg of Prozac. Sometimes we go over that because evidence shows that patients with anxiety and ocd tend to require higher doses. And it might take a few weeks to months for the meds to work, but they do work!

Saying this as a board eligible psychiatrist who treats ocd, and also as a patient. I remember a few months after getting to like... Celexa 40mg, and I noticed I went through a month without thoughts like that and I was like WAIT SO YOURE TELLING ME PEOPLE LIVE LIKE THIS??? LIKE INTRISIVE THOUGHTS ARE NOT NORMAL? Like do people NOT ARGUE WITH THEIR BRAINS EVERY DAY

The Amur Leopard and Clouded Leopard (which recently celebrated its 50th cub born at the zoo!)

The Sumatran Tiger

The Red Ruffed Lemur and Ring-Tailed Lemur

The Cotton-Top Tamarin and White-Cheeked Gibbon

The Colobus Monkey and De Brazza’s Monkey

And the Mexican Spider Monkey!

She played bass on 10,000 songs, including the most-played track of the twentieth century. She was paid $55 per session. Her name never appeared on the albums.

Gold Star Studios, Los Angeles, 1964. A woman in a cardigan walks past the receptionist, a Fender Precision bass in her hand like a briefcase. She doesn’t sign autographs. She signs a timesheet.

Her name is Carol Kaye. In three hours, she will record what will become the most-played track of the twentieth century. She’ll pocket fifty-five dollars and head to another studio, on the other side of town, for the next session.

The record label will never put her name on the album.

Between 1957 and 1973, Carol Kaye took part in roughly 10,000 recording sessions. Not as the featured artist, not as a guest, but as a hired hand. She was part of an anonymous collective nicknamed The Wrecking Crew—elite studio musicians who actually played the instruments on your favorite records while the famous bands posed for promotional photos.

The work was relentless. Three albums before the day was over. Stale coffee in paper cups. No rehearsal. The charts arrived minutes before the tape rolled. If you couldn’t read a chart and nail the take in two tries, you didn’t get called for the next session.

Carol could do it on the first try.

She started playing guitar in grimy bars at fourteen because her family couldn’t pay the electric bill. Music wasn’t a romantic dream for her. It was survival. It was a job—factory work with better acoustics and lower pay.

But she was faster and sharper than almost everyone else. She corrected charts in pencil while the producer was still explaining what he wanted. In one session in 1968, she told a famous producer his arrangement sounded like a dying dog. She chose her own line. They kept her version.

That descending bass line that drives the Beach Boys’ “Wouldn’t It Be Nice”? Carol Kaye. The propulsive groove of “These Boots Are Made for Walkin’”? Carol Kaye. The acoustic-guitar intro to “La Bamba”? Carol Kaye. The iconic theme from Mission: Impossible? Carol Kaye.

She invented techniques on the spot, out of sheer necessity. When the bass sound was too muddy for AM radio, she stuck felt under the strings and used a hard pick instead of her fingers. The tone cut through the static like a blade. It became the sonic signature that defined 1960s pop.

Bassists spent years—decades—trying to crack the secret of the Beach Boys’ gear to get that sound. They were studying the wrong people. They should have been studying Carol.

She received no royalties. No residuals. No gold-record ceremony. No credit on the album sleeves. When “You’ve Lost That Lovin’ Feelin’” hit number one, Carol was already back in a studio cutting a soap jingle.

The biggest bands mimed her bass lines on TV variety shows. New York marketing departments decided a mom in classic clothes didn’t fit the rebellious-youth image they were selling. So they simply left her name off the album credits.

For thirty years, almost no one cared. The truth only began to surface in the late 1990s, when music researchers found the same union contract numbers on thousands of hit records. The very documents meant to preserve studio musicians’ anonymity betrayed them.

Think about it. Every time you heard “Good Vibrations,” “River Deep – Mountain High,” the Righteous Brothers, Nancy Sinatra, or Sonny and Cher, you were hearing Carol Kaye. She composed the soundtrack of an entire generation’s youth.

And yet the records still say nothing. She’s now over eighty. She wrote instructional books. She trained countless bassists. She is finally starting to be recognized by music historians who uncovered the truth about The Wrecking Crew.

But she never got what she deserved: her name on those albums. Credit for the music that defined an era. Recognition that those bass lines everyone associates with the “Beach Boys” were, in fact, Carol Kaye’s.

Fifty-five dollars a session. Ten thousand sessions. The most-played track of the twentieth century.