Question

The Environmental Protection Authority claims that its regulatory procedures for use of a new pesticide are safe. The basis of the claim is that regulation is built around the 1 mg/L no observable effect concentration recorded in toxicological testing. (a) What is meant by no observable effect concentration in the context of toxicology testing? (five marks) Concerned stakeholders carry out their own toxicology tests and summarise results using 95% confidence intervals as shown below. (b) Do these results support the Authority's claim that regulatory procedures for use of a new pesticide are safe? In your answer, explain the term 'statistical power' and its relevance here. (ten marks) zero (control) 1 mg/L 2 mg/L 3 mg/L concentration effect

Answer 1

(a) No-observed-effect level (NOEL) is the maximum concentration upto which there is no undesirable change happen in growth, development or on life span of any individual and it’s must for any toxicology testing because only after knowing this we can have standards regarding the safety limit of any chemical.

(b) If we see the effect that 1 mg/L will have and compare it to zero or controlled level of pesticides than we can see that at 1 mg/L there are effects of pesticides and hence I don’t go with the recommendation of authority stating that pesticides are safe because even at 2 mg/L the effects are similar to that if 1 mg/L.