Answer: Well all of your examples are correct. But I´m having an issue with "introducing new substances or species".
Explanation: It´s more difficult than you can imagine, introducing new stuff into an enviroment (any kind) that has existed for thousand or even millions of years is not that simple. I mean, yes. The enviroment has experimented all kind of changes: extinction of species, annihilation via flood or massive fires. But the cause is always familiar, bornt from the enviroment. Or at least directly relationated with it. There are literally like a dozen of movies that talks about why introducing new species to an enviroment it´s a bad idea.