Which of the following is an early effect of radiation exposure?

The early effects of radiation exposure manifest shortly after the exposure occurs and typically involve damage to rapidly dividing cells. Hair loss, diminished sperm count, and skin burns are all examples of such early effects.

Hair loss, or alopecia, occurs because hair follicles contain rapidly dividing cells that are sensitive to radiation. When these cells are damaged, it can lead to hair falling out, commonly seen after significant radiation therapy or exposure.

Diminished sperm count results from the radiation's impact on the spermatogenic cells in the testes, which are also rapidly dividing. Even low to moderate levels of exposure can harm these cells, leading to temporary or permanent infertility.

Skin burns can occur due to radiation exposure affecting the skin epithelial cells, which regenerate quickly. These burns often result from high doses of radiation, leading to immediate cellular damage and inflammation in the skin.

Given that all three effects are associated with the rapid turnover and sensitivity of the respective cells to radiation, the correct answer encompasses all of them, validating the choice that all of the listed items are early effects of radiation exposure.