Toxicology
(a) Using a specific example, illustrate how fungal contamination of food can cause poisoning to humans.
(b) Antidotes are often used in the treatment of poisoning. Discuss the development of antidotes from historical times through to the modern day. Explain when antidotes would be used then name two antidotes and the poisons they work against.

(c) Write out the acronym TWA in full, and then explain how it is used as a measure of chemical exposure.

2. Answer ALL of the following parts.
(a) Why is the term LD50 becoming unpopular as a descriptor of toxicity?
What are its limitations?
(b) A car repair garage has a paint spraying booth, operated by two workers for 8
hours per day.
The first worker moves the vehicles in and out of the booth and is exposed to
paint fumes for 5 minutes per hour and the concentration of the paint fumes is
320 ppm.
The second worker operates the spray gun from outside the booth and is
exposed to paint fumes all shift and the concentration of the paint fumes is 10
ppm.
Using the threshold weighted average method, calculate the exposure to
paint fumes for each worker.
Comment on the results.
(c) Explain how toxins may be removed from the body by gastrointestinal
decontamination.

 
3. Answer ALL of the following parts.
(a) Occupational exposure limits are considered a good way to prevent harmful
exposure to toxic substances. Discuss why this is so, and outline any advantages they offer compared to LD50 values.
(b) Give one example of a ‘professional poisoner’ at work. Discuss the method of
poisoning and why it was successful.
(c) Explain why and when antidotes are used in the treatment of poisoning. Give
TWO examples of toxins and their corresponding antidotes.
(d) Explain why laboratory analysis is not always the first priority in treating
patients who have suffered poisoning.