Research a carcinogen that can be classified as either an environmental or occupational toxicant that has had relevance in the news within the last five years. In your paper, analyze

Research a carcinogen that can be classified as either an environmental or   occupational toxicant that has had relevance in the news within the last five   years. In  your paper, analyze and briefly summarize the situation that brought the   carcinogen to newsworthy status. Discuss the exposure limits of this   carcinogen, and how individuals were exposed. Also, discuss the toxicological   effects that were not only observed, but all of the possible effects of this   agent. In referencing  Chapter 23 from your assigned reading, briefly discuss   the models used for assessing cancer risks.