Vikas Duggal

RADON MONITORING IN GROUNDWATER SAMPLES FROM SOME AREAS OF NORTHERN RAJASTHAN, INDIA, USING A RAD7 DETECTOR

Radon monitoring has been increasingly conducted worldwide because of the hazardous effects of radon on the health of human beings. In the present research, groundwater samples were taken from hand pumps at different areas of the districts of SriGanganagar, Hanumangarh, Sikar and Churu in northern Rajasthan. RAD7, an electronic radon detector (Durridge co., USA), was used to estimate the radon concentration in groundwater used for drinking. Radon concentration in the groundwater ranged from 0.5 ± 0.3 Bq l(-1) (Chimanpura) to 85.7±4.9 Bq l(-1)(Khandela) with an average value of 9.03±1.03 Bq l(-1). In 89 % of the samples, radon concentration is well below the allowed maximum contamination level (MCL) of radon concentration in water of 11 Bq l(-1), proposed by US Environmental Protection Agency (USEPA). Only in 11 % of the samples, the recorded values were found to be higher than MCL proposed by USEPA and only in 5 % of the samples, the recorded values were found to be higher than the values between 4 and 40 Bq l(-1) suggested for radon concentration in water for human consumption by the United Nations Scientific Committee on the effect of Atomic Radiation (UNSCEAR). The annual effective dose in stomach and lungs per person was also evaluated in this research. The estimated total annual effective dose of adults ranged from 1.34 to 229.68 µSv y(-1). The total annual effective dose from three locations of the studied area was found to be greater than the safe limit (0.1 mSv y(-1)) recommended by World Health Organization and EU Council.

Determination of 222RN level in groundwater using a Rad7 detector in the Bathinda district of Punjab, India.

Radon gas is a significant health threat linked to thousands of preventable deaths each year. In this paper, radon activity concentration is measured in 260 groundwater samples collected from 65 villages in the Bathinda district of Punjab State, India, using Rad7, an electronic radon detector (Durridge Co., USA). The radon concentration varies from 0.9 ± 0.2 to 5.1 ± 0.3 Bq l(-1) with a mean value of 2.63 Bq l(-1). The recorded values of radon concentration in groundwater are within the safe limit of 11 Bq l(-1) recommended by the US Environmental Protection Agency. The annual effective dose in stomach and lungs per person is also evaluated in this research. The estimated total annual effective dose of adults ranged from 8.82 to 49.98 µSv y(-1). The total annual effective dose from all locations of the studied area is found to be within the safe limit (0.1 mSv y(-1)), recommended by World Health Organisation and EU Council.

Assessment of natural radioactivity levels and associated dose rates in soil samples from Northern Rajasthan, India

The analysis of naturally occurring radionuclides ((226)Ra, (232)Th and (40)K) has been carried out in 40 soil samples collected from four districts of the Northern Rajasthan, India using gamma-ray spectrometry with an NaI(Tl) detector. The activity concentrations of the samples range from 38±9 to 65±11 Bq kg(-1) with a mean value of 52 Bq kg(-1) for (226)Ra, from 8±8 to 32±9 Bq kg(-1) with a mean value of 19 Bq kg(-1) for (232)Th and from 929±185 to 1894±249 Bq kg(-1) with a mean value of 1627 Bq kg(-1) for (40)K. The measured activity concentration of (226)Ra and (40)K in soil was higher and for (232)Th was lower than the worldwide range. Radium equivalent activities were calculated for the soil samples to assess the radiation hazards arising due to the use of these soils in the construction of buildings. The calculated average radium equivalent activity was 205±20 Bq kg(-1), which is less than the recommended limit of 370 Bq kg(-1) by the Organization for Economic Cooperation and Development. The total absorbed dose rate calculated from the activity concentration of (226)Ra, (232)Th and (40)K ranges from 77 to 123 nGy h(-1) with an average value of 103 nGy h(-1). The mean external (Hex) and internal hazard indices (Hin) for the area under study were determined to be 0.55 and 0.69, respectively. The corresponding average annual effective dose was found to be 0.63 mSv.

Uranium estimation in drinking water samples from some areas of Punjab and Himachal Pradesh, India using ICP-MS

The uranium concentration in drinking water samples collected from areas of Punjab and Himachal Pradesh has been measured using inductively coupled plasma mass spectrometry. The sources of water comprise hand pumps and tube wells. The uranium concentration lies in the range of 1.24-45.42 µg l(-1) with a mean value of 14.91 µg l(-1) in drinking water samples from Punjab and 0.56-10.11 µg l(-1) with a mean value of 2.17 µg l(-1) in Himachal Pradesh. The measured uranium content in 4 % water samples from Punjab has been found to be higher than the limit of 30 µg l(-1) recommended by the World Health Organization (WHO) and US Environmental Protection Agency. However, the uranium concentration in all the water samples from Himachal Pradesh is well below the recommended limit. The annual effective dose associated with drinking water due to uranium concentration is estimated from its annual intake using dosimetric information based on International Commission on Radiological Protection 72. The resulting value of the annual effective dose from drinking water sources is in the range of 0.33-37.78 µSv, which is well within the limit of 100 µSv recommended by the WHO.

A study of seasonal variations of radon levels in different types of dwellings in Sri Ganganagar district, Rajasthan

Abstract An indoor radon survey has been carried out in 50 dwellings situated in Sri Ganganagar district of Rajasthan using a time-integrated passive technique containing LR-115 type II solid state nuclear track detectors exposed for four seasons of 3 months each covering a period of 1 y. Indoor radon concentration values varied from 144 ± 20 to 259 ± 67 Bq m−3 in winter, 111 ± 23 to 156 ± 64 Bq m−3 in rainy, 97 ± 13 to 156 ± 19 Bq m−3 in summer and 103 ± 17 to 213 ± 76 Bq m−3 in autumn time and the average values were found to be 182 ± 31, 126 ± 15, 119 ± 20 and 146 ± 30 Bq m−3, respectively. The annual average indoor radon concentration varied from 114 ± 18 to 194 ± 45 Bq m−3 with an average of 143 ± 21 Bq m−3, which is less than the lower limit of the action level (200–300 Bq m−3) recommended by International Commission on Radiological Protection. The annual exposure to occupants, annual effective dose and lifetime fatality risk in dwellings varied from 0.50 to 0.85 WLM with an average of 0.63 WLM; 1.95 ± 0.31 to 3.32 ± 0.78 mSv y−1 with an average of 2.45 ± 0.36 mSv y−1 and 1.51 × 10−4 to 2.56 × 10−4 with an average of 1.89 × 10−4, respectively. Measured values for winter/summer, winter/rainy and winter/autumn radon ratios were found as 1.54 ± 0.29, 1.48 ± 0.35 and 1.28 ± 0.24. An effort has been made to find possible relationships of indoor radon levels with building construction materials and ventilation condition of dwellings.

Indoor radon measurements in the dwellings of Punjab and Himachal Pradesh, India

The measurement of indoor radon concentrations were performed in the dwellings of the Punjab and Himachal Pradesh, India by using LR-115 type II Solid-State Nuclear Track Detectors in the bare mode. The annual average indoor radon concentrations in the dwellings are found to vary from 114 to 400 Bq m(-3) with an average of 194 Bq m(-3). In ∼22 % of the dwellings the indoor radon activity concentration values lies in the range of action level (200-300 Bq m(-3)) and in ∼11 % of the dwellings above the upper limit of action level recommended by the International Commission on Radiological Protection (ICRP). The annual effective dose (AED) varies from 2.88 to 10.08 mSv with an average of 4.88 mSv. In most of the villages, the AED lies in the range of action level (3-10 mSv) recommended by the ICRP. The seasonal variation in indoor radon reveals the maximum values in winter and minimum in summer. The winter/summer ratio of indoor radon ranges from 1.15 to 1.62 with an average of 1.31. Analysis of ventilation conditions reveal that the indoor radon concentration values are more in poorly ventilated dwellings compared with the well-ventilated ones.

Radon levels in drinking water of Fatehabad district of Haryana, India

Radon concentrations were measured in 59 groundwater samples collected from Fatehabad district of Haryana, India. The measurements were performed by RAD7 an electronic radon detector manufactured by Durridge Company Inc. The measured radon concentration ranged from 1.4 to 22.6Bql-1. 14% of the groundwater samples were above the United States Environmental Protection Agency recommended value for radon in water. The annual effective dose for ingestion and inhalation was also evaluated in this research. The total annual effective dose due to ingestion and inhalation of radon in drinking water varied from 14.1 to 221.8µSvy-1.

Measurement of indoor radon concentration and assessment of doses in different districts of Northern Rajasthan, India:

Radon (222Rn), the immediate decay product of radium, is a causative agent of lung cancer. The seasonal indoor radon concentration in houses with different floorings, walls and roofs has been measured in Northern Rajasthan, India. The measurements were made in 100 houses using LR-115-type II plastic track detectors over four successive three-month periods (winter, spring, summer and autumn). The mean values of indoor radon concentrations in winter, spring, summer and autumn were determined to be: 176 Bq m−3, 131 Bq m−3, 120 Bq m−3 and 151 Bq m−3, respectively. The annual average indoor radon concentrations in the dwellings were found to vary from 117 to 215 Bq m−3 with an average of 144 Bq m−3. In ∼10% of the dwellings the indoor radon activity concentration values lies in the range of action level (200–300 Bq m−3) recommended by International Commission on Radiological Protection. The annual effective dose received by the residents of the study area varied from 2.0 to 3.67 mSv with an average of 2.46 mSv. The seasonal variation in indoor radon reveals the maximum value in winter and minimum in summer. The influences of the factors linked to building characteristics in relation to radon measurements were examined.

Risk assessment of metals from groundwater in northeast Rajasthan

The present study was conducted to investigate trace metal (Li, Be, B, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As Se, Mo, Cd, Sb, Ba and Pb) concentrations of drinking water samples in northeast Rajasthan, India. Furthermore, the study aimed to ascertain carcinogenic and non-carcinogenic health risks of metals by ingestion and dermal absorption pathways to the local residents. Metal concentrations were analyzed by using high resolution inductively coupled plasma mass spectrometry and compared with permissible limits set by the Bureau of Indian Standards, United States Environmental Protection Agency and World Health Organization. The results indicate that the concentrations of Be, B, Al, Cr, Fe, Cu, Zn, As, Mo, Sb and Ba were lower than their respective permissible limits, whereas the concentrations of Mn, Ni, Se, Cd and Pb in some samples were higher than their permissible limits.The total hazard index (summing the hazard index through ingestion and dermal routes) at all the sampling sites exceeded or nearing unity, indicating the presence of non-carcinogenic health effects from ingestion of water and dermal contact with water. The results indicate that the total excess lifetime cancer risk (considering both ingestion and dermal exposure pathways) of metals exposure was in accordance to the acceptable lifetime risks for carcinogens in drinking water (10-6–10-4). Both carcinogenic and non-carcinogenic risks were mainly attributed to the ingestion pathways.

Analysis of radon concentration in drinking water in Hanumangarh district of Rajasthan, India

Radon levels were measured in drinking water samples collected from Hanumangarh district of Rajasthan, India. The measurements were performed by RAD7 an electronic radon detector manufactured by Durridge Company Inc. The radon concentration in these samples is found to vary from (1.6 ± 0.6) to (5.4 ± 0.7) Bq/l with a mean value of (3.3 ± 1.1) Bq/l. These recorded values are compared with the safe limit values recommended for drinking water by various health and environmental protection agencies. The recorded values of radon concentration are within the safe limit of 11 Bq/l recommended by the US Environmental Protection Agency. The annual effective dose for ingestion and inhalation is also evaluated in this research. The estimated total effective dose varies from 4.29 to 14.47 μSv/year. The total effective dose in all locations of the studied area is found to be within the safe limit (0.1 mSv/year) recommended by World Health Organization and European Council.