Contribution of soil in the annual effective dose due to radon in the air of some dwellings in the city of Karbala, Iraq

Abstract

Introduction: The radon isotopes are not as significant as (222Rn) due to the decay of the natural radionuclides (235U), (232Th) and (238U) due to their short half-life, at most. (222Rn) can be classified as among the most harmful radioactive elements in the world. Material and method: In this analysis, the closed-can technique was used with solid-state nuclear track detectors (CR-39). After forty days of closed dosimeter buried in the soil of the garden, and ninety days from the closed position in the air of some dwellings were collected dosimeter and stripped of nuclear detectors impact of closed groups. For 8 hours, CR-39 detectors were chemically etched by (6.25 N) NaOH solution at 70°C and then registered within an optical microscope. Result: The levels of soil radon concentrations ranged from 28.44±0.58 to 479.76±2.43 Bq/m3 with a mean value of 220.33±1.64 Bq/m3, while the concentration of radon in the air of certain dwellings varied from (1.95±0.27 to 46.82±0.75) Bq/m3 with an average value of 21.51±0.54 Bq/m3. In comparison, the annual effective dose attributed to radon in soil ranged from 0.71±0.09 mSv/y to 12.10±0.38 mSv/y with an average value of 5.55±0.261 mSv/y, while the annual effective dose in air differed from (0.04±0.02 mSv/y) to (1.18±0.12 mSv/y) with an average value of (0.60±0.09 mSv/y). Conclusion: Neglecting the effects of other radon sources, the percentage share of the annual effective dose due to radon in soil measured in the air home, ranged from 0.005±0.001 to 0.453±0.074 with an average value of 0.130±0.040. Weak correlation between concentrations of radon in households and soil air. But roughly speaking, one can say that in soil air every 1000 Bq/m3 and 1000 mSv/y contributes around 130 Bq/m3 and 130 mSv/y in indoor air.