Rajan Jakhu

Assessment of lung dose from indoor 222Rn and 220Rn exposure in the Jalandhar and Kapurthala districts of Punjab, India

Radon (222Rn) and its progenies are the main source of the inhalation dose received by humans due to natural radioactivity. Residential houses of different villages of Jalandhar and Kapurthala districts of Punjab, India, were chosen for the present study. An attempt has been made to estimate the dose to lung (DRL) due to indoor 222Rn concentration. The results of observed values of dose rate to lung (Dlung), dose to tracheo-bronchial region (DT-B), dose to pulmonary + pulmonary lymph region (DP+PL), dose to lung (DRL) from 222Rn exposure and dose to lung (DTL) from indoor Thoron (220Rn) exposure along with their indoor concentration are summarized in this manuscript. The average value of the measured 222Rn (CR) and 220Rn (CT) concentration in air is 38 and 61 Bq m−3. The value of Dlung varies from 0.76 to 2.52 nGy h−1. The average value of the DT-B, DP+PL and DRL is 1.82, 1.82 and 3.65 nSv, respectively. The average dose received by the lungs from 220Rn exposure is 0.06 µSv. Since the dose in the study area is less than reference level of 10 mSv as recommended by the International Commission on Radiological Protection (ICRP), the studied area is safe from the exposure risk of indoor 222Rn and 220Rn.

Exposure assessment of natural uranium from drinking water

The uranium concentration in the drinking water of the residents of the Jaipur and Ajmer districts of Rajasthan has been measured for exposure assessment. The daily intake of uranium from the drinking water for the residents of the study area is found to vary from 0.4 to 123.9 μg per day. For the average uranium ingestion rate of 35.2 μg per day for a long term exposure period of 60 years, estimations have been made for the retention of uranium in different body organs and its excretion with time using ICRPs biokinetic model of uranium. Radioactive and chemical toxicity of uranium has been reported and discussed in detail in the present manuscript.

Risk estimation and multivariate statistical analysis of the heavy metal content of drinking water samples

Drinking water samples of Jaipur and Ajmer districts of Rajasthan, India, were collected and analyzed for the measurement of concentration of heavy metals. The purpose of this study was to determine the sources of the heavy metals in the drinking water. Inductively coupled plasma mass spectrometry was used for the determination of the heavy metal concentrations, and for the statistical analysis of the data, principal component analysis and cluster analysis were performed. It was observed from the results that with respect to WHO guidelines, the water samples of some locations exceeded the contamination levels for lead (Pb), selenium (Se), and mercury (Hg), and with reference to the EPA guidelines, the samples were determined unsuitable for drinking because of high concentrations of Pb and Hg. Using multivariate statistical analysis, we determined that copper, manganese, arsenic, Se, and Hg were of anthropogenic origin, while Pb, copper, and cadmium were of geogenic origin. The present study reports the dominance of the anthropogenic contributions over geogenics in the studied area. The sources of the anthropogenic contaminants need to be investigated in a future study.

Measurement of uranium and radon concentration in drinking water samples and assessment of ingestion dose to local population in Jalandhar district of Punjab, India

A study was conducted to assess the concentration of uranium and dissolved radon in drinking water samples collected from Jalandhar district of Punjab, India. The samples were analysed for dissolved radon using scintillation cell method. Laser fluorimetry was used for measurement of uranium concentration. Correlation analysis of radon and uranium concentrations and salinity and total dissolved solids with uranium was carried out. The uranium concentration in water samples varied from a minimum value of 1.53 ± 0.06 mg m−3 to 50.2 ± 0.08 mg m−3 with a geometric mean value of 14.85 mg m−3. The radon concentration in water varied from a minimum value of 0.34 ± 0.07 kBq m−3 to a maximum value of 3.84 ± 0.48 kBq m−3 with a geometric mean value of 1.46 kBq m−3. Ingestion dose to local population, due to radon and uranium in drinking water, for different age categories, was computed and results are being reported in this paper.

Estimation of Radiological Dose From Progeny of 222Rn and 220Rn Using DTPS/DRPS and Wire-Mesh-Capped Progeny Sensors.

Radon (222Rn) and its decay products are the major sources of natural radiation exposure to general population. The activity concentrations of unattached and attached short-lived 222Rn and thoron (220Rn) progeny in indoor environment of some dwellings of the Jalandhar and Kapurthala districts of Punjab had been calculated using the deposition-based progeny sensors (DRPS/DTPS) and wire-mesh-capped (DRPS/DTPS) progeny sensors. The observed concentration of attached 222Rn and 220Rn progeny showed the variation from 5 to 21 Bq·m−3 and 0.3 to 1.7 Bq·m−3, respectively. The activity concentration of the unattached 222Rn and 220Rn progeny varies from 1 to 5 Bq·m−3 and 0.1 to 0.6 Bq·m−3, respectively. The average unattached fraction of 222Rn and 220Rn progeny is 0.2 and 0.1. The average value of the indoor aerosol concentration attachment rate of 222Rn and 220Rn progeny is 2251 cm−3, 24 ms−1, and 617 ms−1. Relation among the unattached fraction and attachment rate is established, and the obtained results of dose conversion factors show the significance of the nano-sized 222Rn decay products in 222Rn dosimetry.