Well, it goes without saying that paper plates are bad for the planet’s health because they are single-use utensils, so contribute to unnecessary waste. Paper is not a naturally water-resistant material, chemicals are applied to paper plates to make them waterproof, which can then go into waterways and the environment.
These chemicals are called per-and poly-fluoroalkyl substances, which can be dangerous to humans in large amounts. They are not dangerous in small quantities, but it’s possibly not worth the risk of exposing yourself to them at all and using plant-based plates, like those made from bamboo, instead.