Comparison of three analytical techniques for determination of Th and U in environmental samples.

Alpha-particle spectrometry, gamma spectrometry and neutron activation analysis techniques for determination of Th and U in environmental samples have been compared. The analytical parameters studied include detection limit, accuracy, repeatability, reproducibility and surrogate recovery. The results show that neutron activation analysis technique has the best accuracy among the studied techniques; the other two techniques were assessed relative to it. The percentage difference between the three techniques results is about [-20, 20]. In addition, U and Th concentrations are generally overestimated by gamma spectrometry and alpha-particle spectrometry in all cases except Th concentration in the former technique, which is underestimated.

Monitoring of ¹³7Cs fallout in Syrian environment.

This paper presents measurements of cesium 137 ((137)Cs) in the Syrian environment during the period between 2006 and 2010. More than 1,000 samples of soil, water, plants and aquatic life were collected from different locations. The measurements were realized using gamma spectroscopy, and the results showed that radioactivity concentrations were low overall. Concentrations ranged from below detection limits to several tens Bq kg(-1) (dry matter) or 9.8 mBq L(-1) (water), which were well below maximum allowable levels in food or drinking water as established according to Syrian national standards or the WHO/FAO Codex guidelines. However, high (137)Cs activity levels were observed in soil samples collected at a high elevation (Kadmous highs), where a mean concentration of 1,900 Bq kg(-1) was obtained.