Which radiation unit quantifies the biological effectiveness of absorbed ionising radiation by incorporating weighting factors for the type of radiation and the tissue irradiated?

• A Gray
• B Becquerel
• C Roentgen
• D Sievert ✓

Explanation

The sievert is the SI unit of equivalent and effective dose, obtained by multiplying the absorbed dose by radiation and tissue weighting factors, so it expresses biological harm. The gray measures absorbed energy per kilogram of tissue without any weighting, the becquerel measures radioactivity as disintegrations per second, and the roentgen is an old unit of exposure in air. Only the sievert accounts for differing biological effectiveness.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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