concentration

Erdogan M, Eren N, Demirel S and Zedef V. (Department of Physics, Faculty of Science, Selcuk University, 42070 Konya, Turkey) are the Authors of “Determination of radon concentration levels in well water in Konia, TURKEY”.

Radon (222Rn) gas measurements were undertaken in 16 samples of well water representing different depths and different types of aquifers found at the city centre of Konya, Central Turkey.

The radon activity concentrations of the well water samples collected by Authors in the spring and summer seasons of 2012 were measured by using the radon gas analyser “AlphaGUARD PQ 2000PRO”.

The radon concentrations for spring is 2.29±0.17 to 27.25±1.07 Bq l-1. The radon concentrations for summer is 1.44±0.18 to 27.45±1.25 Bq l-1.

The results at hand revealed that the radon concentration levels of the waters strictly depend on the seasons and are slightly variable with depth.

The Authors say that 11 of the 16 well water samples had radon concentration levels below the safe limit of 11.11 Bq/l recommended by the United States Environmental Protection Agency (EPA).

However, all measured radon concentration levels are well below the 100 Bq/l safe limit declared by the World Health Organisation (WHO).

The effective doses resulting from the consumption of these waters were calculated: they are 0.29 µSv/y (minimum value) and 5.49 µSv/y (max value).

More informations about this study can be read at PubMed (PMID 23595410).

Andrea Alessandro MUNTONI

Szabó K. Z., Jordan G., Horváth A. and Szabó C. (Lithosphere Fluid Research Laboratory, Department of Petrology and Geochemistry, Eötvös University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary) have studied the temporal variation of soil gas radon activity concentration in a highly permeable sandy – gravelly soil (k = 2.0E-11 m2) in order to understand if temporal variation of soil gas radon activity concentration can affect geogenic radon potential determination.

Geogenic radon potential provides information about the potential risk from radon. Its calculation takes into account the equilibrium, saturated at infinite depth, soil gas radon activity concentration (C∞). This concentration may vary at annual time scale due to the environmental conditions.

A long-term (yearly) and high temporal resolution (15 minutes) observation, applied in the study, reveal various temporal features such as long – term trend, seasonality, daily periodicity and sudden events in soil gas radon time series. Results show seasonal and daily periodical variation of the measured soil gas radon activity concentration (CsoilRn) in a highly permeable sandy-gravelly soil with definite seasons without obvious long transitional periods.

The winter, from October to April (during the monitoring period) is characterized by 2.5 times higher average soil gas radon activity concentration (median is 7.0 kBq m-3) than the summer, from August to September and May, June, July during the monitoring, when the median of activity concentration is 2.8 kBq m-3.

Daily periodicity, which is much less than the seasonal one, controls the soil gas radon activity concentration mainly in the summer season. Average (AM) value of CsoilRn – say the Authors – is higher at night than in the daytime with about 18% in summer and 3.8%  in winter.

As a conclusion, in case of single CsoilRn measurement on a highly permeable (k ≥ 2.0E-11 m2) soil, similar to the test site condition told by Authors, the measured CsoilRn should be corrected according to the seasons for calculating the equilibrium activity concentration C∞ value.

For more informations about the study, we invite you to read the full text on PubMed.

Andrea Alessandro MUNTONI

The radon concentration is measured in Becquerel per cubic meter (Bq/m³) in the International System of Units or in Picocuries per liter (pCi/L).

What is the actionable concentration of radon activity recommended by different International Organizations and States?

World Health Organization (WHO)

100 Bq/m³

2.7 pCi/L

European Union (EU)

200 Bq/m³ (new constructions, after 1990)

400 Bq/m³ (old buildings, until 1990)

Italy (I)

500 Bq/m³ (valid in a lot of workplaces, italian law D.Lgs. 230/1995)

400 Bq/m³ (italian law about natural radioactive radiation in workplaces, D.Lgs. 230/1995)

Environmental Protection Agency (USA)

150 Bq/m³

4.0 pCi/L

Health Canada

200 Bq/m³

5.4 pCi/L

United Kingdom (UK)

200 Bq/m³

5.4 pCi/L

Dott. Ing. Andrea Alessandro MUNTONI