Relationship between short and long term radon measurements

Variation of indoor radon concentrations in two-storey houses in Nowshera District, Pakistan

A study was performed for the measurement of indoor radon concentration in two-storey houses in district Nowshera in the Khyber Pakhtunkhwa province of Pakistan. This area was not previously surveyed for such kind of study. The aim was to find some correlation of radon levels in first and second storey houses in the area. The measurements were carried out for 1 y from 1 December 2012 to 30 November 2013 using CR-39 detector. The area was divided into four parts, namely, Jhangera, Nowshera city, Akora Khattak and Pabbi. In the first storey houses, radon concentration ranged from 29 to 103 Bq m(-3) with the mean value of 64 ± 12 Bq m(-3) and that in the second storey houses ranged from 25 to 92 Bq m(-3) with the mean value of 56 ± 11 Bq m(-3). Relatively higher values of indoor radon levels in the first stories than the second stories were observed in all four parts of the study area. The effective doses received by the residents of the area were estimated for each part. The mean annual effective doses received by the inhabitants of the area from indoor radon ranged from 0.68 to 2.88 mSv with the mean value of 1.68 ± 0.32 mSv. The doses received by the people of the area were within the ICRP-65 recommended range (3-10 mSv).

Study of indoor radon concentrations and associated health risks in the five districts of Hazara division, Pakistan

A total of 200 indoor air samples were collected to measure radon concentration levels and its contribution to the mean effective doses during different seasons of the period 2009-2010 at different sites of the five districts of Hazara division, Pakistan. The major portion of the region is mountainous and is full of thick forests which receives heavy snow fall in winter. The need for conducting the present survey relied on the fact that occupants spend their lives in poorly ventilated indoor environments of the region, especially in the winter season when they use wood fire inside their residences. The measurements of indoor air samples were taken with RAD-7, a solid state α-detector. Radon concentrations in the whole region range from 41 Bq m(-3) to 254 Bq m(-3) with a geometric mean of 128 Bq m(-3). Radon progenies were measured with a surface barrier detector through alpha spectroscopy from which the Equilibrium Factor (EF) for radon and Radon Decay Products (RDPs) for the smoke-bearing as well as smoke-free indoor environments were deduced. The respective mean values of EF were calculated as 0.49 ± 0.08 and 0.40 ± 0.07. The mean effective doses from indoor air of Abbottabad, Mansehra, Haripur, Battgram and Kohistan districts were calculated as 3.5 ± 1.2, 3.7 ± 0.7, 3.9 ± 1.0, 3.6 ± 1.1 and 3.9 ± 0.7 mSv a(-1) respectively, with the maximum value of 5.1 ± 1.8 mSv a(-1) in Kohistan district during winter and the minimum value of 2.9 ± 1.0 mSv a(-1) in Abbottabad district during summer. The annual exposure dose to the inhabitants of the locality lies below the upper bound of 10 mSv a(-1), as recommended by ICRP-65, and may not pose any significant threat to the public health.

Nano-size radon short-lived progeny aerosols in Slovenian kindergartens in wintertime

Indoor air concentrations of radon and radon short-lived decay products, equilibrium factors, unattached fractions of radon short-lived decay products (f(un)), relative humidity, and temperature have been measured in 29 rooms of 13 Slovenian kindergartens, with an emphasis on f(un) as a crucial parameter in dose assessment. Dose conversion factors, based on the measured f(un) values were compared to epidemiology-based value of 5 mSv WLM(-1).