Questions 3 each 200 word anwers APA style need completed by 1/22/2013 3:00PM EST

1.   
Discuss the findings of recent epidemiological studies on ozone. You may use the information in your text, or the EPA website (http://www.epa.gov/). After analyzing this information, do you think that the EPA should set lower limits on ozone emissions? Why, or why not?
Your response should be at least 200 words in length. You are required to use at least your textbook as source material for your response. All sources used, including the textbook, must be referenced; paraphrased and quoted
2.   
How do epidemiologists distinguish between correlation and causation? Discuss the elements of Hill’s criteria, and provide an example of how correlation can be confused with causation. Your response should be at least 200 words in length. You are required to use at least your textbook as source material for your response. All sources used, including the textbook, must be referenced; paraphrased and quoted material must have accompanying citations.
Discuss the three main types of toxicology studies. What are the benefits and drawbacks of each? Your response should be at least 200 words in length. You are required to use at least your textbook as source material for your response. All sources used, including the textbook, must be referenced; paraphrased and quoted material must have accompanying citations.  

Textbook info:
Introduction to Air Pollution Science: A public he (Rev: 1st) ISBN# 978-0-76-378044-9, Phalen, R.F., & Phalen, R.N.