Rachel Feltman: Happy Monday, listeners! For Scientific American’s Science Quickly, I’m Rachel Feltman. Let’s get this week off to a great start by catching up on some recent science and tech news you may have missed.
We’ll start with some potentially paradigm-shifting research on the human ovary. According to a new study published in Aging Cell, these aren’t just reproductive organs. Long after ovaries stop producing eggs, the researchers say, the organs continue to evolve.
Building off of previous work in mice, the study examined normal ovarian tissue from 28 postmenopausal women between the ages of 50 and 75. The researchers analyzed nearly 6,000 different protein groups to track not just how postmenopausal ovaries differed from reproductively active ones but to see how they changed over decades of postreproductive life. And they did find changes. While the younger ovarian samples had more proteins associated with maintaining tissue structure, samples from older subjects had more proteins tied to inflammation and immune activity.
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What remains to be seen is whether postmenopausal ovaries are doing something beneficial or something harmful—or whether that’s a scale that can tip one way or the other depending on unknown factors. Given how long the ovaries have broadly been treated as useless bystanders once fertile years are past, we’ll probably be working to uncover their mysteries for quite some time.
Staying on the health beat, let’s talk about microplastics. One of the reasons that plastic has become such a ubiquitous material for things like food packaging and toys is that it’s meant to be really stable, in the chemical sense of the word—it’s a polymer, which is a long chain of molecules that doesn’t really easily react with other molecules it comes into contact with. But the stability of a polymer doesn’t mean the plastic object it ends up in is totally inert. Lots of additives commonly used in plastics, like flame retardants and colorants, are prone to leach out into surrounding materials. Bisphenol A, or BPA, which helps make plastic clear and durable, is just one particularly infamous example of an additive that seeps into food and can interfere with human hormone signalling. We also now know that microplastics—tiny particles that flake away into the environment as factors like heat and UV exposure cause plastic to degrade—have made their way into locations as remote as Antarctica and as intimate as human placentas and brains. While research on the exact impacts of microplastic on human health is very much in its early stages, they’ve been linked to inflammation, cellular damage, altered metabolic function and other serious issues in animal studies.
In a study published last Wednesday in the journal Nature, researchers report that even plastics that aren’t leaching out additives could cause problems. In fact, the very geometry of microplastics could make them more hazardous to human health.
The new study found that when exposed to water, microplastics spontaneously generated the kinds of highly reactive molecules that can damage cells. And more and more of that dangerous chemistry took place as the pieces got smaller. The researchers believe that’s because, as plastic breaks down into smaller pieces, it has more and more surface area. Imagine setting up a banquet hall with nine identical folding tables pushed together to make one big ole square that could fit, say 24 people comfortably. If you split the tables into three rectangles instead, you’d have more potential seats exposed—more surface area—and you’d double your comfortable seating to 48. Set up all nine tables individually, and you’ve got room for 72 place settings. It’s the same amount of table as you started with, but with way more edge exposed.
The same thing happens when plastics break down into micro and nano particles: the total volume of plastic remains the same, but more of it is exposed to whatever surrounds it—including human tissue, which happens to be full of water. While more research is needed to confirm this process and understand its potential impacts, we do know enough to say that you should try to limit your exposure to microplastics. Try to avoid microwaving food in plastic, and keep bottled water away from sunlight exposure which can cause the bottles to degrade.
And while we’re on the subject of avoiding microplastics, let’s shoutout one exposure you might not be aware of, teabags. Research published last week in npj Science of Food quantified microplastics in tea brewed from loose leaves compared to tea bags. Because FYI, those silky looking pyramid-shaped bags are made from plastic, and even many paper tea bags are sealed shut with plastic glue. The new study found that bagged tea could contain more than 1/5th of the European Food Safety Authority’s tolerable daily intake of BPA. So it might be a good time to invest in a tea strainer, preferably one made out of ceramic or stainless steel.
Speaking of hot and dangerous food, hackers have found a new way to wreak havoc on the meatspace. Last week, freezers and fridges in hundreds of French supermarkets were reportedly targeted by a cyberattack aimed at spoiling their wares. The hackers took over software from the Danish firm Danfoss that many major retailers use to regulate their refrigerators remotely. The attack raised temperatures to as high as 122 degrees Fahrenheit and kept them elevated overnight, causing food to spoil.
If you want to learn more on how cyberattacks can target physical infrastructure and how benevolent hackers are working to help protect us from threats like these—check out our September 2 episode.
I know this is shocking but I think I’m gonna wrap us up with a fun animal story. Though this particular study is only fun to think about theoretically and gets pretty unpleasant if it gets too close to home. It has to do with how honeybees do their stinging.
When worker bees sting a target and then fly away, they leave their stingers behind—and those stingers keep, well, stinging. In a study published last week in the Proceedings of the National Academy of Sciences, researchers analyzed high-speed videos of honeybee stingers to reveal how they keep pumping venom sans bee.
Now, to the naked human eye a stinger looks like a pretty simple stabbing weapon, but it’s actually a sophisticated instrument. In addition to a venom sac and a pumping chamber, along with muscles and nerves, each stinger contains two sharp lancets that slide on a rail system, kind of like a reciprocating saw. Each lancet has its own attached valve that sits in the pumping chamber. And according to the new study, where scientists had bees sting a clear gel made to mimic human skin, those valves are the key to a stinger’s pumping power. On each downstroke of the lancet the attached valve inflates like parachutes, which creates a pressure seal and pushes venom out. Then as the lancet shoots back up, the valve deflates. The valves are also able to squeeze past one another, so they pump in opposite directions and maintain a continuous flow. Pretty cool, as long as you’re not the person on the receiving end.
That’s all for this week’s science news roundup. We’ll be back on Wednesday to talk to one of my favorite authors of science fact and fiction about their latest book.
Science Quickly is produced by me, Rachel Feltman, along with Fonda Mwangi, Allison Rodgers and Jeff DelViscio. This episode was edited by Alex Sugiura. Marielle Issa and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news.
For Scientific American, this is Rachel Feltman. Have a great week!
