Question

Review the following chart and answer the following questions:

Based on LD₁₀, which toxicant is more potent? Why?

Toxicology Chart

Dose	Toxicant A	Toxicant B
mg/kg	% lethality	% lethality
0.01	20	25
0.05	25	30
0.1	30	35
0.5	40	40
1	45	50
5	55	65
10	60	70
50	70	85
100	75	95
500	95	105
1,000	100	107
5,000	105	108
10,000	107	109

I do not understand if LD10 is the same as 10% lethality

Answer 1

. Lethal Dose 10% or 10% lethality ( LD10 ) — refers to the dose at which 10% of the individuals will die.

Based on the given data, a graph was plotted as shown below:

	% Lethality	% Lethality
Dose mg/kg	Toxicant A	Toxicant B
0.01	20	25
0.05	25	30
0.1	30	35
0.5	40	40
1	45	50
5	55	65
10	60	70
50	70	85
100	75	95
500	95	105
1,000	100	107
5,000	105	108
10,000	107	109

• 10% lethality dose is lower for Toxicant B as compared to Toxicant A. So Toxicant B is more potent.
• Please note, this inference is based on extrapolation to 10% lethality as the data doesnot cover it. For this a curve fitting software can be used with sigmoidal fitting feature.