Answer:
It occurs in the cytoplasm. Glycolysis also involves two stages which break up glucose. In the 1st stage, Glucose is broken into two phosphorylated 3-carbon compounds through a series of reactions.
For the environmental risk, it is much better to prevent pollution than to deal with it after it has already been made. When you deal with the pollution, it is hard to say that you can eliminate completely. So, prevention is the first strategy.