Yeah, it’s not microplastics per se, just volatile organic compounds that leech into the saline over time. The smell/taste is because those VOCs want to be in the air. So when they hit your lungs, they very happily evaporate and you exhale them. So you’re just tasting your own breath. Like there may be microplastics present, but that’s not what you’re smelling/tasting, because those wouldn’t evaporate into your lungs to be exhaled.