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The blocking effect of 222Rn gas and its progeny by various face masks has been determined using a measurement system with a parallel AlphaGUARD detector. The theoretical approach of diffusion rate for different particle sizes was calculated. The filtering effect of the different masks followed the order N99 > surgical > N95 > double cloth > double cellulose > cloth > cellulose masks, respectively. Overall the blocking effect percentage ranged between 7.65 and 22.66%. The study indicated that the effect of a mask with high quality in filtering the gas of 222Rn and its decay products is more than the double-layer masks. [ABSTRACT FROM AUTHOR]

The effect of natural gas use on indoor radon concentrations was studied in the dwelling of two cities in Cyprus using an AlphaGUARD radon detector. The radioactivity concentration of 222Rn capsule natural gas samples were measured, and the contribution of natural gas consumption to generate indoor 222Rn in residential houses was calculated. The average values of the indoor 222Rn concentrations were found between 42.16 and 146.47 Bq m−3 in CNG and LPG samples, respectively. The obtained annual effective dose and excess lifetime cancer risk (ELCR) have been compared with the world average values specified by the WHO and UNSCEAR reports. [ABSTRACT FROM AUTHOR]

The 226 Ra concentration and some physicochemical parameters have been measured in thermal spring waters used for medical therapy and drinking purposes in the Astara basin of North Guilan, Iran. The radon emanation method was performed using the AB-5 photomultiplier tube to measure the 226 Ra concentration in water samples. Also, the physicochemical parameters of the water were measured in situ using a portable multimeter-VWR multi. The average concentrations of 226 Ra were ranged between 3.4 ± 0.06 to 38.2 ± 0.08 mBq l -1 . For all samples, the 226 Ra concentration values range is lower than the maximum admissible value recommended by the WHO report. The relation between the physicochemical parameters and 226 Ra activity concentration of groundwater was assessed. The results indicate a significant correlation coefficient between 226 Ra concentration and T, as well as acidity pH. Anomalously high 226 Ra concentrations in groundwater are preferentially found in high temperate and electric conductivity along with the acidic environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This research attempted to investigate the plant/soil concentration ratios (CRs) of 137 Cs and 40 K in plants that grow on the Anzali Lagoon of the Caspian coast, Iran. The activity concentrations of 137 Cs and 40 K were measured in soil samples, annual plants (Echinochloa crus-galli, Digitaria sanguinalis, and Trifolium repens), and perennial plants (Phragmites australis, and Cynodon dactylon). The relationship of activity concentration with soil particle density, and pH of soil samples, CR, and 137 Cs/ 40 K discrimination factor (DF) were determined. The activity concentration of 137 Cs in the soil, annual plants, and perennial plants ranged between 12- and 124 (Bq/kg dry weight), 2- and 17 (Bq/kg dw), and 2 - and 14 (Bq/kg dw), respectively. The geometric mean (GM) values of DF in annual and perennial plants were 0.57 and 0.55, respectively. The CR for 137 Cs and 40 K varied as a non-linear relation in annual plants and perennial plants. This study showed that the CRs for 137 Cs in annual plants were higher than the CRs for perennial plants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)