Use of Gamma ray Spectrometry to Asses a First Order Exposure Risk for the persons residing in Ludhiana District of Punjab, India

The measurements of 226Ra, 232Th and 40K using gamma spectrometry is used to assess a first order exposure risk for the persons residing in Ludhiana district of Punjab, India. The concentration of Radium, Thorium and Potassium in the soil samples varies from 20.43 Bqkg-1 to 34.78 Bqkg-1, 62.34 Bqkg-1 to 148.21 Bqkg-1 and 345.56 Bqkg-1 to 549.88 Bqkg-1 respectively with average values of 28.39, 111.29 and 468.01 Bqkg-1 respectively. The radium equivalent activity (Raeq) calculated for the same soil samples vary from 143.55 Bqkg-1 to 265.57 Bqkg-1 with an average value of 220.29 Bqkg-1. The values of absorbed dose and annual effective dose (indoors and outdoors) are found to vary from 68.09 n Gy h-1 to 121.96 n Gy h-1, 0.33 mSv y-1 to 0.60 mSv y-1 and 0.08 mSv y-1 to 0.15 mSv y-1 respectively. The radium equivalent activities in all the soil samples were found to be lower than the limit (370 Bqkg-1) set in the Organization for Economic Cooperation and Development (OECD) report and the value of External Hazard Index (Hex) in all the samples is less than unity with an average value of 0.60