Authors:T. Hutchinson, S. Aufreiter, and R. Hancock
Gold has been mined on a large scale at Yellowknife located in the sub-arctic North West Territories of Canada since 1938.
The gold is associated with arsenopyrite ores, with necessitates the oxidation of the arsenic and sulphur by roasting at two
Yellowknife smelters. Other metals are also present in the ore, notably antimony. As2O3 and SO2 are emitted into the atmosphere. Large quantities of arsenic were liberated in the past and despite improvements in emission
control, significant emission still occur. In order to assess the amount and extent of arsenic contamination in the local
environment and the potential exposures and sources to man, soil samples and samples of the native vegetation were collected
in and around the town of Yellowknife and the two smelters. Arsenic and antimony analyses were done by instrumental neutron
activation analysis using the SLOWPOKE facility at University of toronto. Air-dried plant samples were bombarded at a neutron
flux of 1·1012n cm2s and soil samples at 2.5·1011n cm2s for 6 minute periods. The122Sb and76As-ray emissions at 559 keV were analysed after decay periods of 24–48 hours and compared with standard solutions and NBS
standards. Zinc, copper, lead and cadmium analyses were done by atomic absorption spectrophotometry.
Arsenic was found to be accumulated in the soils in the vicinity of the two smelters to levels of several thousand ppm. Concentrations
greater than 500 ppm occurred in the soil of Yellowknife townsite, and greater than 50 ppm occurred at all sites sampled within
15 km of the town. Antimony levels were about 10% of arsenic and were highly correlated with arsenic. Zinc occurred to 500
ppm around the smelters.
Compared with background levels, the foliage of several native species showed substantial arsenic accumulation, up to several
hundred ppm in birch. Only 5–25% of this arsenic could be removed by careful washing. Evidence suggests the arsenic is taken
up from the soil creating an ongoing arsenic contamination problem. Soil arsenic levels are also sufficiently high to inhibit
root growth in soils over a very extensive area.
Authors:Y. Kawabata, M. Yamamoto, V. Aparin, S. Ko, K. Shiraishi, M. Nagai, and Y. Katayama
Water and phosphorous fertilizer samples from Karakalpakstan in the Republic of Uzbekistan were analyzed by inductively coupled
plasma mass spectrometry, (ICP-MS) to demonstrate the water quality in drinking water, rivers and canals. Uranium concentrations
exceeded the WHO (2004) guideline levels for drinking water at some sampling points. Since uranium can also have a toxic effect
on kidneys, the effect of uranium from drinking water on people in these areas is significant. One of the main pollutant sources
is the phosphate fertilizer leached from agriculture land.
Radioactivity of Linhchi mushrooms (Ganoderma Lucidum) cultivated in laboratory and production conditions has been measured in the Environmental Laboratory of Nuclear Research Institute (NRI), Dalat, Vietnam. The results showed that Linhchi mushroom has a high radioactive concentration of137Cs, which is about 20 Bq kg–1 fresh weight. In addition, the radioactive contents of substrata before and after cultivation were insignificant. This suggested that Linhchi mushroom should only accumulate the137Cs radioisotope from the atmosphere, directly. Therefore, it should be considered as a bio-indicator for environmental monitoring.
Density metering instruments, based on the attenuation of gamma-rays, are used for non-intrusive monitoring of fluids, solids
and gases. Applications include thickness gauging, fluid level indicators and determining the composition of two phase systems.
This paper describes a study to investigate how the technology can be developed for environmental monitoring and control.
Environmental pollutants, Zn and Pb, were selected for the initial study. A 3.7 GBq241 Am source was used to measure the sensitivity of the technique at 17, 20, 26 and 59.5 keV with a Ge planar semiconductor
detector for optimum resolution of the photon energies. The optimum thickness for measurements using these four energies was
4 cm. The equipment was calibrated with a 2000 mg/l solution of zinc chloride and a 1000 mg/l solution of lead nitrate. A
series of lower concentration solutions were measured to test the accuracy of the method, and demonstrated agreement with
the actual concentrations within statistics. The sensitivity of the equipment was 100 mg/l for zinc and 50 mg/l for lead.
The limitation to accuracy and precision was the stability of the counting equipment and theoretical detection limits of around
20–50 mg/l should be achieved if the stability of the electronics is improved.
Authors:Mahdi Sadeghi, Milad Enferadi, Mohammadreza Aboudzadeh, and Parvin Sarabadani
This article presents, 122Sb (T1/2 = 2.723 days, Iβ- = 97.59%) was produced via the natSn(p,xn) nuclear process at the AMIRS (Cyclone-30, IBA, Belgium). The electrodeposition experiments were carried out by potassium
stannate trihydrate (K2Sn(OH)6) and potassium hydroxide. The optimum conditions of the electrodeposition of tin were as follows: 40 g/L natSn, 20 g/L KOH, 115 g/L K2Sn(OH)6, DC current density of 5 A/dm2 with a bath temperature of 75 °C. The electroplated Tin-target was irradiated with 26.5 MeV protons at current of 180 μA
for 20 min. Solvent extraction of no-carrier-added 122Sb from irradiated Tin-natural target hydrochloric solution was investigated using di-n-butyl ether (C8H18O). Yields of about 3.61 MBq/μAh were experimentally obtained.
Authors:P. de Souza, R. de Queiroz, T. Morimoto, A. Guimarães, and V. Garg
The application of Mössbauer spectroscopy, X-ray diffractometry, thermogravimetric analysis and PIXE in the characterization of the particulate matter in atmospheric aerosols in Metropolitan Region of Vitória (MRV), Brazil have been investigated. The main sources of particulate matter, natural, industrial and antropogenic from human activities, have been studied to identify its contribution in the atmospheric particles. During the years 1995 to 1999 samples of total suspended particles (TSP, Ø 100 m) were collected from four points within MRV. The inhalable particles (PM10 Ø 10 m) and sedimented particles (SP) were also collected from the same region. A receptor modeling was used for the identification of the source of particulate matter in the collected urban aerosol.
Authors:M. Freitas, M. Reis, L. Alves, H. Wolterbeek, T. Verburg, and M. Gouveia
During the months of July and August 1993 a lichen collection campaign was held in Portugal where about 250 samples were collected and analysed by thick target TIPIXE and INAA. Results for 44 different elements were obtained and a data base was built and subjected to Monte Carlo Aided Target Transform Factor Analysis (MCATTFA), a method developed at IRI (Delft). 10×10 km2 coast and 50×50 km2 far from coast sampling grids were used for collection. In this work we will present the results which were obtained based on a reduced data set of 36 elements measured by INAA. The results for 22 elements obtained by TTPIXE were published elsewhere. In this work we will also present the conclusions considering all the 44 elements determined by both techniques.
Authors:A. El Hossadi, A. Alian, S. Ali, R. Farooq, A. Hamid, and Tahra Majed
Nondestructive neutron activation analysis has been used for the analysis of 17 out of 24 elements in 12 samples of air particulate matter collected from various localities in Benghazi. Both relative and monostandard methods were used. The neutron activation method was supplemented with graphite furnace atomic absorption, so that most toxic elements could be assayed in the same samples. Thus Cd, Cr, Cu, Mn, Ni, Pb, V and Zn could be analysed quantitatively in most of the samples. It has been found that contamination of the atmosphere of Benghazi with dust is largely due to heavy construction work in the city, action of wind on the surface of land around the city and the release of exhaust products from vehicles and airplanes. Particular contamination due to industrial activities was not noticeable. Results on samples from Benghazi were compared with those from Prague, Munich and Sendai.
Methodologies for analysis of anthropogenic and natural radionuclides in marine samples were developed and applied in environmental
samples. Results of systematic measurements of these radionuclides have showed that artificial radioactivity levels are in
agreement with the values from the regions not affected directly by nuclear accidents or nuclear reprocessing plant discharges
and are due to the global fallout. The average concentration of137Cs is of 1.4 Bq·m−3 in seawater, ranges from 13 to 220 mBq·kg−1 in fish, and from 0.4 to 1.8 Bq·kg−1 for sediments.90Sr levels in seawater are of 1.8 Bq·m−3 and in fish vary from 19 to 75 mBq·kg−1. Sediments present concentrations of90Sr lower than 0.8 Bq·kg−1 and for239+240Pu of 0.03 to 0.18 Bq·kg−1.210Po levels in fish range from 0.5 to 5.3 Bq·kg−1. The data generated represent reference values for our country and are used to estimate the intake levels of these radionuclides
by consuming of marine products.