字幕表 動画を再生する 英語字幕をプリント You've probably heard of microplastics — those teeny tiny fragments of plastic waste. They're commonly found in the ocean when larger chunks of plastic like water bottles break down over time. And that's obviously problematic. And now scientists are finding a whole new type of plastic that's even smaller. What's smaller than micro? Nano. To start, a microplastic is any piece of plastic that's smaller than 5 millimeters in size. These pieces can break into smaller and smaller bits to become nanoplastics, which are smaller than one-thousandth of a millimeter. That's smaller than a single cell. So, to count something that small and figure out the impact it's having on our ocean environment, researchers are having to get creative with their detective work. French researcher Alexandra Ter Halle and her team use actual crime scene forensic techniques to find the nanoplastics in sea water. They take samples, ignite them into a gas, and shoot them with electrons. This causes the nanoplastics to transfer an electric charge, which they can then measure to learn more about what kinds of nanoplastics are present in the samples. Even though they're too small to be seen, nanoplastics can be detected clearly enough to reveal their weight. This same method is used at crime scenes to detect the presence of explosive gases, biological agents or residues. But some ocean experts think that the key to better understanding nanoplastics is modeling, rather than sampling on a small scale. The Tracking of Plastic in Our Seas Project uses present knowledge of the tides, currents, and wind patterns to predict the surface paths that plastic would follow. Since the team is not only interested in modeling surface plastic, but also the plastic beneath the waves, their models include simulations of plastic fragmentation, sinking, beaching, wave-mixing, and animal ingestion. Along with data collected in the field, the team is using laboratory wave tank tests to better picture the ocean in 3D. Where other maps only show the ocean from a top-down perspective, having a 3D representation will let them see underneath the surface. They hope to use this information to determine where the nanoplastics are and what organisms may be most at risk. Related research, though still quite new, is finding that nanoplastics can accumulate in bloodstreams and cell membranes. In one experiment, they could even pass the blood-brain barrier in a fish, hinting at neurological damage. Nanoplastics also pose a threat because they attract metals like lead, which are dangerous for animals to consume. Emerging studies have also suggested negative health impacts from the chemicals in microplastics on humans, such as reproductive harm, organ problems, and developmental delays. This makes nanoplastics beg an even bigger question of how we may be affected. But in order to understand the true impact of nanoplastics, it's critical that we develop better ways to study it and calculate its actual volume. Some additional forward-looking solutions include using satellites or even LIDAR to find and identify plastic in the ocean. So hopefully, these steps will help bring us closer to tackling our massive plastic problem. In case you didn't know, it's Plastic Free July. If you want to know more about what's being done to combat plastic pollution, check out our playlist here. And if there are any ways that you're reducing your plastic footprint, let us know down in the comments. For even more plastic news, make sure to subscribe. Thanks so much for watching, and I'll see you next time.
B1 中級 ナノプラスチックが海洋プラスチックの常識を変えようとしている (Nanoplastics Are Changing Everything We Know About Ocean Plastic) 11 0 Summer に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語