Over pollution
Your report needs four sections plus the literature cited. These sections can be separate with headings or part of an overall paper. There is no minimum length, but you probably need at least one full page (and two is better).
The four sections are:
1. Basic overview of the entire issue – what is it?
2. History of the problem
3. What is being done about the problem or what do people propose should be done?
4. Your thoughts on the issue – synthesize all of the above sections and try to draw some conclusions of your own