Radon concentration in drinking water sources of the region adjacent to a tectonically active Karak Thrust, southern Kohat Plateau, Khyber Pakhtunkhwa, Pakistan

Abstract

A total of 84 drinking water samples from tube wells, natural springs, hand pumps and open wells in the region adjacent to a tectonically active Karak Thrust, Pakistan, were analyzed for radon content determination. These samples have a mean, maximum and minimum radon values of 9.4 ± 0.4, 25.1 ± 0.9, and 1.1 ± 0.2 Bq l -1 , respectively. This study indicates that 24 % of samples from tube wells, 44 % from springs, and 50 % from hand pumps have radon levels in excess of the EPA recommended maximum contaminant level of 11.1 Bq l -1 . The mean annual effective doses of all the samples are lower than the reference level of 0.1 mSv a -1 . Drinking water from majority of the sources within the region is generally safe as far as radon related health hazards are concerned with exception of few isolated cases.

Factors Controlling the Spatial and Temporal Variability in Groundwater 222Rn and U Levels

“…This may be due to the fact that fractures with higher permeability/porosity can increase bedrock surface area in fault zones, allowing 222 Rn to dissolve from the bedrock into groundwater through active water-rock interactions. Previous studies have reported that fractures can enhance emanation surfaces, allowing 222 Rn to escape from rocks via α-recoil [32,33]. The relatively lower 222 Rn concentration in groundwater close to Faults B and C may be due to the different lithology (gneiss) of those well locations.…”

Radon doses in the indoor environments of Murree and Islamabad, Pakistan: A comparison of active and passive techniques

“…Assuming 7000 h per year indoors (an occupancy factor of 80%) and an equilibrium factor of 0.4, the concentration of 1 Bqm −3 is equivalent to 1.56 × 10 −2 m Jhm −3 . Based on the International Commission on Radiological Protection (ICRP) 1993 25 radon dose conversion, exposure to radon at 100 Bqm −3 will be equivalent to an annual effective dose of 1.72 mSvy −1 . 26 Similarly, using the UNSCEAR 2000 recommendation of 9 nSv (Bqhm −3 ) −1 , the effective dose for one year radon exposure at 100 Bqm −3 is 2.5 mSv.…”

“…1 There are three naturally occurring radioactive isotopes, namely, radon, 222 Rn (T 1/2 = 3.82 days), thoron, 220 Rn (T 1/2 = 55.6 s) and actinon, 219 Rn (T 1/2 = 3.6 s) which belong to the natural decay series of 238 U, 232 Th and 235 U, respectively. 2 Of these isotopes, radon ( 222 Rn) is the most significant isotope. Its relatively long half-life (3.82 days) enables it to migrate quite significant distances before decaying.…”

Estimation of radon concentrations and associated radon doses by using active technique in drinking water sources of Abbottabad, KPK, Pakistan

“…1,2 Therefore, to protect public health from harmful radiation hazards of radon and to determine seismic-related changes in the radon content of water, continuous monitoring of radioactivity in drinking water, mineral water and thermal water is necessary. 3–6 In surface water, the radon concentration levels are generally very low in the range of few kBq m −3 , 7 while the highest concentrations of dissolved radon are found in ground water flowing through granite or granitic sand and gravel formations, ranging from 1–50 kBq m −3 in aquifer and sedimentary rocks, 10–300 kBq m −3 in very deep wells and 100–50,000 kBq m −3 in crystalline rocks. 8–13 Various radon surveys have been conducted around the globe for determining the baseline data of the studied areas.…”