UV-Aged Plastic Bits Boost Mercury Harm in Marine Tiny Crustaceans Over Generations

Tiny plastic bits exposed to sun's UV light. These bits, called nanoplastics, can change over time, affecting how they interact with metals like mercury. But what happens when these aged nanoplastics meet mercury, and how does it impact marine life? A study looked into this with a tiny crustacean named Tigriopus japonicus, over multiple generations. The researchers found that aged nanoplastics acted like a better carrier for mercury. In fact, they increased mercury buildup in the crustaceans by around 1. 5 to 1. 6 times more than fresh nanoplastics. This might be due to the increased ability of aged plastics to latch onto mercury. When mercury joined forces with aged nanoplastics, it hit the crustaceans harder. Their survival rate dropped significantly, by about 74% in the first generation (F1) and 62% in the second generation (F2). This could be because the aged nanoplastics and mercury combo caused the most drastic changes in the crustaceans' genes. These changes affected their outer shell, turned on their antioxidant defenses, and messed with their reproductive genes. So, this study shows that old plastic bits can be a big problem when they team up with mercury. It also sheds light on how long-term exposure to both plastic pollution and metal contamination can hurt marine creatures.