May 23, 2024: Marmite metal extraction, microplastics in testes, and how wind shear can tear a hurricane apart. —Andrea Gawrylewski, Chief Newsletter Editor | | | Aerial view of the island nation of Tuvalu, one of the first countries likely to disappear due to climate change. Brandi Mueller/Getty Images | | | • An international court governing the world's oceans ruled this week that countries must protect marine environments from climate change by cutting their planet-warming pollution. | 4 min read | | | • An atmospheric scientist explains what wind shear is and how it can tear a hurricane apart. | 3 min read | | | For any readers who love marmite, scientists have found it could be an Earth-friendly metal recycler. Researchers added 20 liters of the stuff, which is leftover brewer's yeast from beer-making, to a mix of aluminum, copper, nickel and zinc. They discovered that the yeast could isolate and take up specific metals—and be reused at least five times without losing binding strength.
Why this is cool: Brewer's yeast could be an environmentally sustainable alternative to current metal extraction techniques such as pyrometallurgy, an energy-intensive melting process that can release toxic fumes.
What the experts say: "There are huge vats of yeast that often have nowhere to go once brewers are done with them," says Kerry Bloom, a biologist at the University of North Carolina at Chapel Hill. "So this is a fantastic source for it. It's the master recycler." | | | Researchers tested 23 human testicles and 47 dog testicles and found microplastics in every sample, including PET (polyethylene terephthalate) and PVC (polyvinyl chloride). The humans had three times more plastic in their testicles than the dogs did. They also found that dog testes with higher concentrations of certain microplastics tended to have lower sperm counts.
Why this matters: Scientists haven't yet determined the impact of microplastics on human health, but evidence suggests that chemicals in plastics can disrupt hormone signaling in the human body. That could trigger broad health effects, notably reduced fertility. Microplastics have been found in seminal fluid, the placenta, stool, blood and breast milk.
What the experts say: The EPA could evaluate microplastics under the Toxic Substances Control Act. "And the thing about plastics is that their source is fossil fuels," says Tracey Woodruff, an environmental health researcher at the University of California, San Francisco. "We have to reduce fossil fuel use anyway to address climate change—why not also stop companies from turning it into plastic?" | | | • Last fall, scientists announced a breakthrough treatment for sickle cell anemia, made possible by CRISPR gene editing technology. The exorbitant cost of the treatment will be prohibitive to nearly all of the eight million people worldwide who need it. That should prompt a shift toward research on pain management and health equity, writes Shobita Parthasarathy, professor of public policy and women's and gender studies at the University of Michigan. "What if the best way for technology to serve society, and particularly to advance equity, is for governments and innovators to focus on more than creating potentially lifesaving treatments?" she says. | 6 min read | | | In researching a bit more about marmite, I discovered that it's one of those polarizing foods (like blood sausage or anchovies on pizza), and just about half of people in Britain enjoy it, while nearly 40 percent dislike or hate it, according to the market research firm Ipsos. Some strong food feelings can be biologically based--for example, in some places around the world nearly 20 percent of people have genes that make the herb cilantro taste soapy (I personally love it). | Cilantro lovers and haters alike are welcome in the Today in Science community. Reach out anytime with your food bugaboos and any other suggestions: newsletters@sciam.com. See you tomorrow. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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