The study of radiation contamination in roodepoort gold mine tailings using HPGe gamma spectroscopy

In this study, a coaxial HPGe high-resolution <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"> <mml:mrow> <mml:mi>γ</mml:mi> </mml:mrow> </mml:math> -detector was used to measure the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m2"> <mml:mrow> <mml:mi>γ</mml:mi> </mml:mrow> </mml:math> -signals in soil samples collected from the Roodepoort Gold Tailings. There have been complaints about dust from the gold tailings, and the study aims to determine the level of contamination. The activity concentration of 238 U ranged from 132.88 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m3"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 4.68 to 1,421.46 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m4"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 13.38, with a mean of 464.96 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m5"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 2.08 Bq/kg. The activity concentration of 226 Ra ranged from 130.19 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m6"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 4.48 to 1,359.27 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m7"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 13.83, with a mean of 425.28 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m8"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 8.02 Bq/kg. The range of 232 Th was from 5.27 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m9"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 0.67 to 19.37 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m10"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 1.98, with a mean of 11.20 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m11"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 1.03 Bq/kg, and 40 K activity ranged from 65.23 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m12"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 15.29 to 264.11 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m13"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 25.66, with a mean of 127.50 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m14"> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:math> 21.85 Bq/kg. The findings showed that 238 U and 226 Ra activities exceeded the global average of 35 Bq/kg, while 232 Th and 40 K were below their respective limits. The radiological hazard indices exceeded recommended limits, making the tailings soil completely unsuitable for use as building materials, as this may have deleterious health effects on residents in the future.