You have a test group, whereby rats have been exposed to increasing concentration of a toxicant via ingestion. At 250 ppm 50% of the test subjects died. There was no observable effect until 25 ppm and the effects up to 50 ppm were positive. Thereafter adverse effects were witnessed, such as disorientation and weight loss. 1. Draw a dose response curve to demonstrate the information provided above. Ensure to label both axis, the threshold, the NOEL, the NOAEL and the LD50. (10 Marks) 10 marks for each question: looking at labeling, curve drawing, accurate numbers that are being requested and units (if applicable). 2. -Rats were exposed to an increasing concentration of a toxicant via inhalation. At 35 ppm all of the test subjects died. At 15 ppm a reaction was noted in the rats, they were seen to be quicker at solving a maze; but just 5 ppm more of the toxicant made the rats confused and just 5 more ppm and half of the rats died. (10 Marks) 3. Chemical "work at school (WAS)" has a half-life of 3 hours. A Student works with WAS; 5 days then gets the weekend off. On Friday, the student is done school at 4:00 and it was noted that there was a blood concentration of WAS in the student's brain level of 600 mg/I. At the start of the next week at 8:00 am; how much "work at school (WAS)" will be lost? How many half-life's will have occurred? Show your work. (10 Marks) 4. If you cannot find an OEL in the Alberta OHS Code book what should be your next steps? Assume that each step was not successful...what would you do next?.Finally, your last step is successful and how did you find the OEL for the toxin? Why did you do that? (10 marks)