Pollution may be caused by natural sources or human activities, but regardless of the cause, the result is the same. It can have detrimental effects on aquatic ecosystems as well as the health of those who depend on those sources of water, like us!
review verb (THINK AGAIN) C1 [ T ] to think or talk about something again, in order to make changes to it or to make a decision about it: The committee is reviewing the current arrangement/situation. Let's review what has happened so far.
A literature review is an evaluative report of information found in the literature related to your selected area of study. The review should describe, summarise, evaluate and clarify this literature. It should give a theoretical base for the research and help you (the author) determine the nature of your research.