Which statement about LD50 values is true?

Which statement about LD50 values is true?

• A. The pesticide with the lower LD50 is more toxic.
• B. The pesticide with the higher LD50 is more toxic.
• C. LD50 measures chronic toxicity only.
• D. LD50 is unrelated to acute toxicity.

Answer: (A)

LD50 shows how much of a pesticide is needed to kill 50% of a test population, so it directly reflects acute toxicity. A smaller LD50 means a much smaller amount is lethal to half the group, which makes that substance more acutely toxic. LD50 is usually given in mg of chemical per kg of body weight and depends on factors like species, sex, age, and how exposure occurs (oral, dermal, or inhalation). It does not measure chronic, long-term toxicity; that kind of effect is assessed with other metrics such as NOAEL or LOAEL. So the statement that the pesticide with the lower LD50 is more toxic matches what LD50 actually indicates.

LD50 shows how much of a pesticide is needed to kill 50% of a test population, so it directly reflects acute toxicity. A smaller LD50 means a much smaller amount is lethal to half the group, which makes that substance more acutely toxic. LD50 is usually given in mg of chemical per kg of body weight and depends on factors like species, sex, age, and how exposure occurs (oral, dermal, or inhalation). It does not measure chronic, long-term toxicity; that kind of effect is assessed with other metrics such as NOAEL or LOAEL. So the statement that the pesticide with the lower LD50 is more toxic matches what LD50 actually indicates.