Question

Takumi works in his yard for 45 minutes each Saturday. He works in the morning, and he wears sunscreen and a hat each time he works in the yard.

What does Takumi hope to reduce through his actions?

the likelihood of stochastic effects, such as DNA mutations
the severity of stochastic effects, such as cancer
the severity of non-stochastic effects, such as cancer
the likelihood of non-stochastic effects, such as radiation sickness

Answer 1

the likelihood of stochastic effects, such as DNA mutations

Reducing sun exposure (by working in the morning and wearing sunscreen and a hat) lowers the dose and thus the probability of stochastic effects like DNA mutations and skin cancer; stochastic effects change in likelihood with dose, not severity.