Decreased sperm count is possible due to radiation exposure after receiving a threshold of at least:

Decreased sperm count is possible due to radiation exposure after receiving a threshold of at least:

• A. 100 miligray (mGy)
• B. 150 milligray (mGy)
• C. 1500 milligray (mGy)
• D. 3000 milligray (mGy)

Answer: (B)

Germ cells in the testes are extremely sensitive to radiation, so even relatively small doses can affect sperm production. The first dose level at which a noticeable decrease in sperm count is observed is about 150 milligray (0.15 Gy). When exposure reaches this threshold, the radiation injures the rapidly dividing spermatogonia, leading to a drop in sperm production that may be temporary as the germ cells recover over time. Higher doses tend to cause more prolonged or even permanent effects, but the initial, detectable decrease aligns with the 150 mGy mark. Doses around 100 mGy are below that standard threshold for a consistent decrease, while doses of 1,500 mGy or 3,000 mGy would produce much more significant or lasting damage.

Germ cells in the testes are extremely sensitive to radiation, so even relatively small doses can affect sperm production. The first dose level at which a noticeable decrease in sperm count is observed is about 150 milligray (0.15 Gy). When exposure reaches this threshold, the radiation injures the rapidly dividing spermatogonia, leading to a drop in sperm production that may be temporary as the germ cells recover over time. Higher doses tend to cause more prolonged or even permanent effects, but the initial, detectable decrease aligns with the 150 mGy mark. Doses around 100 mGy are below that standard threshold for a consistent decrease, while doses of 1,500 mGy or 3,000 mGy would produce much more significant or lasting damage.