Life on earth is a complex set of delicately balanced ecosystems. In some ways, it represents a house of cards. Almost every one of the millions of uniquely patterned cards supports others. Some are beautiful and others are plain. Regardless of where they sit or how they look, they are all connected..
it is not even related she is asking why? and your answering something (don't take it seriously just kidding)
1: carelessness about the environment
2: toxic gas released by factories for examplebihar
3: lack of prevention system
these are the reasons that toxic chemical and gases are released into the ecosystem and damages the ecosystem