All living organisms on earth rely on another living organism. If we allow factories to ruin our enviorment we will not only be ruining earth, but ourselves. If factories kill the animals we eat then we may starve to death. As you see killing the animals ruins our life cycle. It hurts us as well.
We rely on waterways as sources of water. If factories pollute them when the water cycle occurs it will cause acid rain. We dont want the animals we eat drinking water that can kill them. If acid rain happens then our crops will be ruined. Acid rain will hurt us more than the enviorment.
If our crops are ruined farmers will not make capial. Without capital farmers can not feed their families. The animals we eat consume crops. The depletion of crops will cause those animals to die. Therefore we need crops to survive.
All in all if factories are polluting the enviorment they should not be able to continue to operate due to the overall outcome of the enviorment.