Thursday Throughput: Phthalates, or Every Sperm is Sacred Edition

Graphic by Jynto, CC0, via Wikimedia Commons

[ThTh1] One of the trends that has caused some consternation has been a steady decades-long decline in sperm counts among men in developed countries. While the numbers are a bit fuzzy, they seem roughly consistent with a 50% decline over the last forty years or so. That’s not enough to threaten the species; we men do produce a lot of those little things. But no one is sure why it is happening or what it means.

Enter the NYT, which never saw a trend it couldn’t stoke panic over. Nicholas Kristof wrote an article last week on the phenomenon:

Sperm counts have been dropping; infant boys are developing more genital abnormalities; more girls are experiencing early puberty; and adult women appear to be suffering declining egg quality and more miscarriages.

The articles quote several scientists who point the finger at “endocrine disruptors”, phthalates in particular.

So, is this something to panic over? Well … maybe. But the case is not nearly as clear as the NYT would like us to believe. Phthalates may be part of the problem. But other factors abound. Emily Oster writes extensively about it here. The short version is that we still don’t know what’s causing the drop in sperm counts.

There are a lot of things which affect sperm count and quality. Here’s an excellent review article, which cites all of the following possible influences: alcohol, smoking, caffeine and related, illegal drugs, diet, supplements, being overweight, being underweight, heat, zinc, copper, selenium, water pollution, other pollutants, pesticides, phthalates, glycol ethers. I myself have written about sperm and tight underwear in the past.

Studies of phthalates tend to be a bit all over the place. In general, they favor an endocrine disruption hypothesis but it’s not nearly definitive. The problem is that these chemicals are in everything we deal with. So, finding a control group for these studies is almost impossible.

(I would add that Kristof lumps together a lot of things that may not be related. Elevated miscarriage rates for example, may be more reflective of increased detection of early pregnancy and increasing maternal age.)

The phthalate molecule that may be corrupting our precious bodily fluids. Or not.

I do think phthalates may be overstaying their welcome. And they are slowly being phased out. If they are the big bad here, we should know relatively soon. But even they are having an effect, I am very dubious that they are the Big Bad Sperm-Killing Wolf. I think Oster is probably right: that there are many factors in modern life that are driving sperm counts downward. Which unfortunately means that a solution is going to difficult to find.

[ThTh2] More good news on the vaccine front. Merck, having watched a vaccine candidate of their own crash and burn, will now be partnering up to produce the Johnson and Johnson vaccine. It will take a few months, but they should be able to achieve a good capacity by summer. This is not only good for the current vaccine push; it’s good for the future if we need to tweak the vaccine to deal with a variant. The more capacity we have, the faster we can respond to the virus’s genetic innovations.

[ThTh3] Did the COVID pandemic chop a year off the average American’s life? No. The method the CDC uses is a bit … complicated. And so, while their number is accurate, it doesn’t represent what the headlines say it represents.

[ThTh4] This got a lot of player on Twitter:

It's -454F degrees in space and the solar panels on the International Space station are working fine. Nasa has been using the Green New Deal for 23 years.

— Scott Huffman (@HuffmanForNC) February 21, 2021

This is … not a good comparison. The ISS is in a 93-minute low-Earth orbit, spending half of that in full sunlight and half in eclipse, running on batteries. There are no clouds, no atmospheric conditions and a great deal of effort goes into orienting the spacecraft so that the solar panels are perfectly aligned with the Sun. These are nearly ideal conditions for solar power; the equivalent on Earth would be building solar panels on in an equatorial desert.

But most of us don’t live in equatorial deserts. Our friend Kristin has gone over this before. It’s not the cold that limits the wintertime use of solar power. It’s the shorter days and the lower altitude of the Sun on the sky. Those factors mean you are getting less energy from the Sun, which is why it is cold in the winter. And if you’re getting less energy from the Sun — and please stop me if I’m going too fast here — you’re getting less energy from the Sun.

Solar power is a part of a carbon-free energy system. But it has issues just like every other form of power. And it would not have made Texas’s power outages go away.

[ThTh5] Was one of the gravitational waves detected in 2019 not a collision between two black holes but between two giant blobs of dark matter? One of the candidates suggested for dark matter is the axion, a theoretical particle that would solve some outstanding problems in particle physics while simultaneously providing a particle that would produce gravity but little to no light. In some forms of this theory, axions would collect into “stars” just like normal matter does. Only these “stars” would not emit any light. They could only be detected by their gravitational influence.

It’s intriguing but I’m not convinced. The more conventional explanations — if two black holes colliding with a violence so intense it literally sends ripples in the fabric of spacetime billion of lights years into the cosmos could ever be called conventional — seem adequate to the task. But it does bear watching for the next phase of LIGO. Because we might get to the point where we can definitively say whether such collisions exist.

LIGO allows us to look at the universe with new eyes. We’re seeing the things we expected to see — colliding black holes and neutron stars. But we may soon start a more exciting phase — seeing the things we didn’t expect to see. (H/T: Chris)

[ThTh6] Speaking of missing matter, we found some. But it’s conventional matter, not the dark stuff.

[ThTh7] I think I’ve seen this movie.

[ThTh8] I won’t claim to understand this at all, but someone solving a decades-old math problem is cool, right?

[ThTh9] A great look at some of the things we got wrong during the pandemic. I’m particularly struck by this:

Socializing is not a luxury—kids need to play with one another, and adults need to interact. Your kids can play together outdoors, and outdoor time is the best chance to catch up with your neighbors is not just a sensible message; it’s a way to decrease transmission risks. Some kids will play, and some adults will socialize no matter what the scolds say or public-health officials decree, and they’ll do it indoors, out of sight of the scolding.

Our friend Gabriel was on this months ago, nothing that by failing to provide students with low-risk social activities, universities guaranteed that students would engage in high-risk social activities. Like it or not, human beings are social animals. And our “abstinence only” approach to COVID-19 has proven to be a fiasco. If we have a pandemic in the future or COVID comes back for a second round, we need to keep this mind. We can’t just lock people in their houses for a year and expect them to be OK with it.

[ThTh10] Just in case you haven’t had your mind blown today.

Inside every proton in your body (and everywhere else) is a roiling storm of matter and antimatter, so complicated that nobody can explain exactly what's happening there. A great mind-bender from @nattyover. https://t.co/gJDoqyOPlL pic.twitter.com/fmyyUXA5EI

— Corey S. Powell (@coreyspowell) February 26, 2021

[ThTh11] What’s that? That didn’t quite fry all your brain cells? Let this zap the remainder:

This image of the Moon is the result of combining approximately 1000 exposures taken with my telescope during different phases to show the full depth of its mountains and craters. One of my most detailed images yet! pic.twitter.com/Ue4F97KHu7

— Cosmos Astro Art (@CosmosAstroArt) February 21, 2021

[ThTh12] As noted a week ago, I got my second dose of the COVID-19 vaccine. My side effects were minimal — a bit of a chill that night. My wife had more significant effects. About 12 hours after the shot, she developed a mild fever and chills. Those symptoms were gone within another 12 hours. That seems to be a fairly common response. What was uncommon was that the vaccine triggered symptoms of her Multiple Sclerosis, which lasted a couple of days.

The first dose of the Pfizer/Moderna vaccine teaches your immune system to recognize the COVID spike protein. But the second provokes a massive immune response, ramping up your immunity to extremely high levels that will crush the virus if it shows up. The downside is that it can make you feel a bit yucky for a little while. The upside … you’re way less likely to catch the disease and massively less likely to die of it.

That seems a decent tradeoff to me.