Since frogs absorb water and oxygen through their skin they also absorb harmful pollutants which might kill them or prevent them from having babies. True but try to find a better example. Their eggs can absorb harmful chemicals along with water and oxygen. They are also vulnerable to UV radiation, the same rays of the sun that cause skin cancer in human beings. This is the best answer.
Frogs are delicate and important creatures.
There aren't even that many different kinds of frogs on the whole earth. This may not seem like many, but considering how important these animals are to the ecosystems where they live, this should make you nervous. No, I'm sorry to say that this isn't true. Yes, but try for a more complete answer. Collecting frogs, especially the colorful poison arrow frogs, has become very popular.