Investigation of natural effective gamma dose rates case study: Ardebil Province in Iran

TLDR

Gamma rays can induce biologically significant chemical changes, and natural environmental exposure generally exceeds man‑made sources. The study aimed to determine natural background gamma dose rates and corresponding annual effective doses in selected cities of Ardebil province. Outdoor gamma dose rates were measured at 105 sites in selected districts of Ardebil province using an ion chamber survey meter. Average absorbed doses ranged from 219 to 358 nSv/h across six sites, with Germi and Kosar near high‑background levels while others were lower, and the province’s mean annual effective dose was 1.73 mSv—roughly twice the global average.

Abstract

Gamma rays pose enough energy to induce chemical changes that may be biologically important for the normal functioning of body cells. The external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined. In this research natural background gamma dose rates and corresponding annual effective doses were determined for selected cities of Ardebil province. Outdoor gamma dose rates were measured using an Ion Chamber Survey Meter in 105 locations in selected districts. Average absorbed doses for Ardebil, Sar-Ein, Germy, Neer, Shourabil Recreational Lake, and Kosar were determined as 265, 219, 344, 233, 352, and 358 nSv/h, respectively. Although dose rates recorded for Germi and Kosar are comparable with some areas with high natural radiation background, however, the dose rates in other districts are well below the levels reported for such locations. Average annual effective dose due to indoor and outdoor gamma radiation for Ardebil province was estimated as 1.73 (1.35-2.39) mSv, which is on average 2 times higher than the world population weighted average.