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.
The format of a review of literature may vary from discipline to discipline and from assignment to assignment. A review may be a self-contained unit -- an end in itself -- or a preface to and rationale for engaging in primary research. A review is a required part of grant and research proposals and often a chapter in theses and dissertations.