Statistical analysis has been performed on the gross alpha- and beta-activity measurements of surface waters collected at
the Atomic Weapons Establishment at Aldermaston (UK) during the period January 2002–September 2005. The results have been
found to follow a lognormal distribution and this has important applications when considering gross activity exemption thresholds.
This implies that the gross activity is the multiplicative product of many small independent factors, such as meteorology,
flow conditions and site operations. The influence of meteorological parameters has been investigated using linear regression,
and some correlation has been identified between gross beta-activity and parameters indicative of fine weather. Variations
in gross activity have been considered on monthly, weekly and daily timescales and characterised using the geometric mean
and geometric standard deviation in accordance with the properties of the lognormal probability density function.
The natural radioactivity concentration and some heavy metals in various water and soil samples collected from seismically
active area have been determined. Gross-alpha and beta concentrations of different 33 water samples and some heavy metal (Fe,
Pb, Cu, K, Mn, Cr and Zn) concentration in 72 soil samples collected from two major fault systems (North and East Anatolian
Active Fault Systems) in Turkey have been studied. This survey regarding gross-alpha and beta radioactivity and some heavy
metals concentrations was carried out by means of Krieger method using a gross-alpha and beta-counting system and atomic absorption
spectrometry (AAS), respectively. Also, gross annual effective dose from the average gross-alpha activity in waters were calculated.
Authors:Marian Calin, Mihaela Calin, Gheorghe Simionca, and Ovidiu Mera
The purpose of the study is to evaluate the activity concentrations and distribution of natural radionuclides in Turda salt
mine having in view the development on the future of the speleotherapy in this salt mine. The radon, gamma ray and gross alpha
and beta radiation measurements have demonstrated the presence of low concentrations of natural radionuclides in rock salt
and soil samples collected from different points of the salt mine and sustains the development of speleotherapy in this mine.
Liquid scintillation counting (LSC) and pulse shape analysis (PSA) was used in measuring radon and gross alpha- and beta-activities in groundwater. We used conventional LSC counters for the measurement of radon in water, but low-background LSC spectrometers for the gross activity measurements. The lower limit of detection (LLD) for radon in water is 0.6 Bq/l for a 60 min count with a conventional counter, but 0.1 or 0.2 Bq/l, with the two types of low-background LSC spectrometers equipped with a pulse shape analyser (PSA). The gross alpha and beta activity measurements are made using a simple sample preparation method, PSA of a low background LSC and spectrum analysis. The LLD recorded for gross alpha and beta with the two spectrometers are 0.02 and 0.03 Bq/l and 0.2 and 0.4 Bq/l, respectively, for a 180 minutes count and a 38 ml sample volume. The method also enable the calculation of the U and226Ra contents in water and indicates the presence of some other long-lived radionuclides (210Pb,228Ra or40K). The LLD for U recorded with both spectrometers is 0.02 Bq–1 and for226Ra 0.01 Bq·1–1. The LLDs attained by this LSC method are two orders of magnitude lower than the maximum permissible concentrations set for U and226Ra.
Authors:J. Dávila Rangel, H. López del Río, B. Rodríguez, and B. Solache-Ríos
The conditions to measure the gross alpha and gross beta radioactivity in water samples from Zacatecas and Guadalupe cities in the State of Zacatecas, Mexico were established. The gross alpha and beta radioactivity of water samples were measured using a liquid scintillation detector. The results show that the gross beta radioactivity in all cases is lower than the maximum contaminant level and the gross alpha radioactivity is higher in the samples collected from Guadalupe City and in the samples collected from the Southwest of Zacatecas City.
Authors:I. Svetlik, A. Belanova, M. Vrskova, E. Hanslik, D. Ivanovova, J. Meresova, L. Tomaskova, and T. Novakova
Gross alpha and beta activity screening methods have been developed to determine whether specific analysis of radionuclides
is required to further characterize water. Our contribution aims at the validation of possible losses of 210Po related to underestimation of the gross alpha activity. The tap water samples likewise the selected samples of surface,
underground, and mineral water were processed. These samples were treated in solutions containing both HNO3 (recommended by ISO standards) and HCl (which could cause significant loses of volatile polonium chloride form during the
sample ignition). Results of several experiments determining the recovery of polonium during the ignition of sample are discussed.
Conditions which can lead to significant losses of polonium are partly demarcated.
A chemical procedure for transferring deposited solid matter from a cellulose filter into the liquid scintillation cocktail has been described. The influence of chemical and color quenching on alpha and beta detection efficiency, as well as on misclassification of beta and alpha pulses was corrected by an external standard method. Under the chosen pulse shape discrimination level (PSD), the alpha and beta detection efficiencies were above 85% and spillovers of alpha and beta pulses were below 10% and 2% respectively. Determination limits for samples containing up to 200 mg of mineral matter were 0.015 mBq m–3 for alpha, 0.055 mBq.m–3 for210Pb and 0.055 mBq.m–3 for beta activity (counting time 12000 s and volume of filtered air 1000 m3). The method has been applied for routine monitoring of210Pb as well as for gross alpha and beta activities of longer-living radionuclides (T1/2.>11 hrs) in suspended air matter.
Authors:P. Saroja, G. Immanuel, G. Raj, and K. Selvan
Gracilaria edulis, an edible red marine macro algae from three high background radiation areas (Arockiapuram, Kadiapattinam and Kurumpanai)
on the southwest coast of Tamil Nadu, and one low background radiation area (Mandapam) on the southeast coast of Tamil Nadu,
in India, were studied for variations in average gross alpha and beta radiation activities. Significant variations in average
gross beta activities were observed while alpha activities showed only marginal variation. The average gross alpha activity
was recorded high (61.51 Bq kg−1) during the post southwest monsoon season, while it recorded lowest (25.48 Bq kg−1) during the post northeast monsoon season. Average gross beta activity varied between seasons with the lowest level (211.55 Bq Kg−1) during post southwest monsoon season and the highest (413.33 Bq kg−1) during post northeast monsoon season. Among the four locations, the gross alpha activity was high (70.95 ± 26.74 Bq Kg−1) in Arockiapuram and low (18.74 ± 6.32 Bq Kg−1) in Mandapam, while the gross beta activity was high (442.25 ± 168.53 Bq Kg−1) in Kurumpanai and low (158.63 ± 34.37 Bq Kg−1) in Mandapam. Average gross alpha activity in G. edulis was found significantly varying in terms of locations, while average gross beta activity for the same species recorded significant
Authors:I. Outola, S. Nour, H. Kurosaki, K. Inn, J. La Rosa, L. Lucas, P. Volkovitsky, and K. Koepenick
In 2004, levels of radioactivity exceeding federal drinking water standards were found by state laboratories in two separate
areas of Maryland through gross alpha and beta screening measurements. It was desired to know which radionuclides were responsible
for the activity and what effect water softener systems installed in individual households had on the mitigating problem.
Non-destructive gamma-spectrometry and gross alpha-beta liquid scintillation measurements, as well as chemical separations
followed by measurements of 222Rn, 226Ra and 228Ra, uranium and thorium isotopes, 210Po, and 210Pb were carried out by National Institute of Standards and Technology (NIST). The results of the studies indicated disequilibrium
among the decay products in the Th and U decay chains had a major influence on the radionuclide content. Unsupported 210Po was found to be the predominant radionuclide in drinking water at one of the locations. Furthermore, the influence of the
use of water softeners was found to be much more effective for radium than for uranium.