Measurements of surface air 7Be concentrations in Saudi Arabia

Abstract The main objective of this study is to identify the atmospheric 7Be concentrations in 130 surface air samples collected from three stations located in Riyadh, Haql and Khafji cities in Saudi Arabia between November 2012 and April 2014. Monthly variations as well as seasonal patterns of 7Be were studied using a medium-volume air sampler and a gamma spectroscopy system equipped with a high-purity germanium (HPGe) detector. 7Be exhibited one maximum specific activity in summer and one minimum in winter with average monthly concentrations of 12.4 ± 0.9, 15.4 ± 1.2, and 18.0 ± 1.3 mBq m−3 in Riyadh, Haql and Khafji, respectively. Overall, the average 7Be concentration in the three stations was 12.9 ± 1.0 mBq m−3, whereas the maximum value of 29.5 mBq m−3 was registered in Khafji city in August 2013. Besides 7Be, measurements indicate observations of 4 K, 137Cs, 226Ra radionuclides in surface air samples collected from the three stations. 4 K showed measurable concentrations, whereas the concentrations of 137Cs and 226Ra were only detected in a limited number of samples.