Komal Saini

Comparative statistical analysis of carcinogenic and non-carcinogenic effects of uranium in groundwater samples from different regions of Punjab, India

LED flourimeter has been used for microanalysis of uranium concentration in groundwater samples collected from six districts of South West (SW), West (W) and North East (NE) Punjab, India. Average value of uranium content in water samples of SW Punjab is observed to be higher than WHO, USEPA recommended safe limit of 30µgl-1 as well as AERB proposed limit of 60µgl-1. Whereas, for W and NE region of Punjab, average level of uranium concentration was within AERB recommended limit of 60µgl-1. Average value observed in SW Punjab is around 3-4 times the value observed in W Punjab, whereas its value is more than 17 times the average value observed in NE region of Punjab. Statistical analysis of carcinogenic as well as non carcinogenic risks due to uranium have been evaluated for each studied district.

A follow-up study on indoor 222Rn, 220Rn their decay product concentrations in a mineralised zone of Himachal Pradesh, India

A follow-up study was taken up in a mineralised zone situated in Hamirpur district, Himachal Pradesh, India, to investigate high values of radon concentrations reported in past studies as well to update the old radon data based on bare SSNTD technique. In the present investigation, the concentrations of indoor radon, thoron and their decay products have been measured using the newly developed radon/thoron discriminating diffusion chamber with single entry face, direct radon and thoron progeny sensors (DRPS/DTPS), respectively. The measurements have been carried out in 75 dwellings of 14 different villages where the previous studies were carried out using bare SSNTD technique. It was observed that high values of earlier reported radon concentrations were mainly due to thoron interference in the Solid State Nuclear Track Detector (LR-115 type II) exposed in bare mode. Now, the average concentration values and the estimated annual inhalation dose in these villages have been found to be within the reference level as recommended by the ICRP. The annual average indoor radon and thoron concentrations observed in these dwellings have been found to vary from 44±12 to 157±73 Bq m(-3) and 44±11 to 240±125 Bq m(-3), respectively. The equilibrium equivalent concentrations of radon and thoron decay products have been observed to be in the range of 10 to 63 and 1 to 5 Bq m(-3), respectively.

Assessment of age-dependent radiation dose and toxicity risk due to intake of uranium through the ingestion of groundwater from Northern Rajasthan, India

ABSTRACT Uranium traces were measured by laser fluorimeter in groundwater samples collected from four districts of Rajasthan state in India. The average values of uranium concentration in groundwater in Sri Ganganagar, Hanumangarh, Churu, and Sikar districts were determined to be: 57, 50, 40, and 21 µg L−1, respectively. These recorded values were compared with the maximum contamination levels recommended for drinking water by various health and environmental protection agencies. The associated age-dependent radiation dose is estimated by taking the prescribed water intake values of different age groups. The average cancer mortality and morbidity risks are calculated to be 5.6 × 10−5 and 8.8 × 10−5 respectively, indicate that the probability of carcinogenic risks is negligible. About half (49%) of the analyzed samples showed hazard quotient > 1.0, indicating significant risk due to chemical toxicity of uranium.

Assessment of carcinogenic and non-carcinogenic risk from exposure to uranium in groundwater from western Haryana, India

This study was carried out to assess the distribution of uranium in groundwater by using LED fluorimeter LF-2a and chemical and radiological risks associated with its consumption in Sirsa district, Haryana, India. Uranium concentration ranged between 0.93 and 290μg l-1 with an average value of 49 μg l-1. About 44% of the groundwater samples had uranium concentration above the maximum contamination level of 30 μg l-1 prescribed by the World Health Organization and United States Environmental Protection Agency and 22% of the samples exceeded the permissible limit of 60 μgl-1 prescribed by the Atomic Energy Regulatory Board, India. The average cancer morbidity and mortality risks are determined to be 1.10 × 10-4 and 7.17 × 10-5 respectively, indicating the negligible carcinogenic risk. Hazard quotient for 44% samples is greater than unity which indicates health risk due to chemical toxicity of uranium in groundwater. The associated age-dependent annual effective dose is estimated by taking the prescribed water intake values of different age groups.

Mapping natural radioactivity of soil samples in different regions of Punjab, India

Thallium activated sodium iodide (NaI(Tl)) detector and multi channel analyzer has been utilized to measure gamma rays emitted by radio nuclides found in soil samples of south-west (SW) region of Punjab state, India where elevated level of uranium of around value of 700µg/l in groundwater has been reported. For comparative study, soil samples were also collected and analyzed from west (W) and north east (NE) regions of the state. Uranium and potassium has been found to be comparatively higher in SW region whereas thorium level is higher in W and NE part of Punjab state. Overall concentration level of naturally occurring radio nuclides 40K, 238U and 232Th has been found to be varied from 260.1±17.3 to 728.2±27.7, BDL to 41.9±10.3 and 29.5±7.1 to 88.1±6.2Bq/Kg respectively. Overall average level of 40K and 232Th has been found to be higher as compared to worlds average concentration level. Average radium equivalent activity (134.8±23.03 (σ) Bq/Kg), dose rate (61.9±10.3nGy/h), outdoor and indoor dose (0.30±0.05 and 0.08±0.01 mSv/year), external and internal hazard index (0.36±0.06 and 0.42±0.08) has been calculated.

Seasonal variability of equilibrium factor and unattached fractions of radon and thoron in different regions of Punjab, India.

A survey was conducted to estimate equilibrium factor and unattached fractions of radon and thoron in different regions of Punjab state, India. Pin hole based twin cup dosimeters and direct progeny sensor techniques have been utilized for estimation of concentration level of radon, thoron and their progenies. Equilibrium factor calculated from radon, thoron and their progenies concentration has been found to vary from 0.15 to 0.80 and 0.008 to 0.101 with an average value of 0.44 and 0.036 for radon and thoron respectively. Equilibrium factor for radon has found to be highest in winter season and lowest in summer season whereas for thoron highest value is observed in winter and rainy season and lowest in summer. Unattached fractions of radon and thoron have been found to vary from 0.022 to 0.205 and 0.013 to 0.212 with an average value of 0.099 and 0.071 respectively. Unattached fractions have found to be highest in winter season and lowest in rainy and summer season.

Estimation of indoor radon, thoron and their decay products’ concentrations along with annual inhalation dose in dwellings of Punjab, India

In the present study, indoor radon and thoron concentrations were assessed using a newly developed pin hole-based twin cup dosimeter with a single-entry face in some areas of Punjab state, India. The equilibrium equivalent concentrations of radon and thoron were estimated directly by using the newly developed progeny (decay products) sensors designed by Bhabha Atomic Research Centre, Mumbai, India. The average radon and thoron concentrations in the study region were found to be 61.6 ± 18.6 Bq/m3 and 68.0 ± 30.8 Bq/m3, respectively, while the average equilibrium equivalent concentrations of radon and thoron were 25.9 ± 7.7 Bq/m3 and 2.2 ± 0.7 Bq/m3, respectively. Calculated average equilibrium factor for radon and thoron was 0.45 and 0.04, respectively, in the present study. The annual inhalation dose that was calculated from the present observed concentrations varied from 1.1 to 4.1 mSv/year with an average value of 2.4 mSv/year, which is well within the reference level of 10mSv/year recommended by International Commission on Radiological Protection. The study shows that thoron is a significant contributor to the inhalation dose, which is about 29% of the total inhalation dose.