Joga Singh

Comparative study of natural radioactivity levels in soil samples from the Upper Siwaliks and Punjab, India using gamma-ray spectrometry

Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. The natural radionuclide (226Ra, 232Th, and 40K) contents in soil were determined for 26 locations around the Upper Siwaliks of Kala Amb, Nahan and Morni Hills, Northern India, using high-resolution gamma-ray spectrometric analysis. It was observed that the concentration of natural radionuclides viz., 226Ra, 232Th and 40K, in the soil varies from 28.3+/-0.5 to 81.0+/-1.7Bqkg(-1), 61.2+/-1.3 to 140.3+/-2.6Bqkg(-1) and 363.4+/-4.9 to 1002.2+/-11.2Bqkg(-1) respectively. The total absorbed dose rate calculated from activity concentration of 226Ra, 232Th and 40K ranged from 71.1 to 162.0nGyh(-1). The radium equivalent (Req) and the external hazard index (Hex), which resulted from the natural radionuclides in soil, were also calculated and found to vary from 149.4 to 351.8Bqkg(-1)and from 0.40 to 0.95 respectively. These values in Upper Siwaliks area were compared with that from the adjoining areas of Punjab. The radium equivalent activities in all the soil samples were lower than the limit (370Bqkg(-1)) set in the Organization for Economic Cooperation and Development (OECD) report and the dose equivalent was within the safe limit of 1mSvy(-1).

Measurement of soil gas radon and its correlation with indoor radon around some areas of Upper Siwaliks, India.

Radon is a radioactive gas which makes the primary contribution to the natural radiation to which people are exposed. For that reason, great importance is attributed to the determination of radon concentration levels in water, indoor air and soil gas and outdoors. In this paper, measurements of radon concentration in soil gas have been carried out around some areas of the Upper Siwaliks of the Kala Amb, Nahan and Morni Hills, India, using a portable AlphaGUARD PQ 2000 device into which the soil gas is drawn using active pumping. The soil gas radon concentration around the Upper Siwaliks was found to vary from 11.5 +/- 0.9 to 78.47 +/- 3.1 kBq m(-3). The annual average indoor radon concentration in the study area was measured in the range from 71.7 +/- 21.0 to 421.7 +/- 33.6 Bq m( - 3) using LR-115 type II cellulose nitrate films in the bare mode. The values of soil gas radon concentration in the study area were compared with those from the adjoining low-radioactive areas of Punjab. Since the soil or bedrock beneath a building is one of the sources of radon gas in the indoor air, an effort has been made to find a possible correlation between soil gas radon with the indoor radon. A satisfactory positive correlation has been observed between soil gas radon and indoor radon in the study area.

Indoor Radon Measurements in Dwellings of Some Areas of Upper Siwaliks, India using SSNTDs

The presence of radon and its decay products in the human environment are considered a potential health hazardous and measurement of them is important to assess the threat they might pose. Keeping this in view, indoor radon measurements were carried out in dwellings of different villages belonging to the upper Siwaliks of Kala Amb, Nahan, and Morni Hills, India using the LR-115 type II cellulose nitrate films in the bare mode. The annual average radon concentration in the studied area was measured in the range from 71.7 ± 21.0 to 421.7 ± 33.6 Bq·m-3. The levels of radon activity were found to be within the action level internationally recommended by ICRP. The average annual effective dose was found to vary from 1.22 to 7.20 mSv per year. Gamma ray activities were also measured in the dwellings of different villages to look for a possible correlation between indoor radon and gamma ray levels in the study area. The values of gamma ray activity were found to vary from 9.75 to 17.50 μR·h-1. The values of indoor radon concentration and gamma ray activity in the study area were compared with those from the adjoining nonradioactive areas of Punjab.

A Study of Groundwater Radon Concentrations in Punjab and Himachal Pradesh States, India

In this paper, the results of radon concentrations in the drinking water in some areas of Punjab and Himachal Pradesh are presented. Samples were collected from the hand-pumps, tube-wells and natural springs, which are the major sources of drinking water in these areas. Radon concentration values in drinking water showed a wide variation depending on its source and location. The radon concentration values in hand-pump drawn groundwater have been found to be higher than the values from other sources. The recorded radon concentration in these samples has been found to vary from 1.0 0.3 to 48.0 2.2Bq·L 1. The radon concentration has also been measured in some thermal springs and these values have been found to be quite a lot higher than from other sources of ground water. Mineral water has the minimum radon concentration compared with groundwater sources.

Regional variations pattern of indoor radon levels in some areas of Punjab and Haryana

The indoor radon concentration levels and their regional variations pattern, for two consecutive half-year periods, in a wide range of dwellings of some regions of Punjab and Haryana states have been studied. The objective was to find the relation between the variations of indoor radon levels with the sub-soil and local geology, type of building materials utilised in the dwellings of the region. Keeping this in view, indoor radon measurements have been carried out in the dwellings of 30 villages around the Tusham Ring Complex, Bhiwani district, Haryana, known to be composed of acidic volcanics and associated granites, along with 11 villages of Amritsar District, Punjab. The indoor radon concentration in the dwellings around Tusham (Haryana) was found to vary from 120 +/- 95 to 915 +/- 233 Bq m(-3), whereas radon levels varied from 60 +/- 37 to 235 +/- 96 Bq m(-3) for the dwellings studied in Punjab. We believe that local geology including embedded granitic rocks, and sub-soil, as well as building materials having higher radioactive content, is the major contributor for the higher indoor radon levels observed particularly in the dwelling around Tusham Ring complex, where some dwellings are showing higher radon concentrations than the ICRP recommendations. The environmental samples from some areas of Punjab state and around the Tusham Ring Complex of Haryana state have also been analysed for radon exhalation studies. Higher values for radon exhalation rates have been observed for the Tushams soil/rock specimens, as compared with soil samples of the Amritsar region of Punjab.