Coal ash as a source of radioactivity in the environment at Svilajnac in 1998

Coal ash was dumped in an area in central Serbia near to Svilajnac. The continual monitoring of coal, ash, water from the waste dump, surface water, agricultural and non-agricultural soils, and vegetation used as a source of human and animal food, for activities of the natural radionuclides 40K, 235U, 238U, 226Ra, 214Bi, 232Th, 234Th, 7Be, 208Tl and 137Cs, and 134Cs, provided evidence of increased levels of radioactivity in this region due to coal ash. Samples in the form of ash, water, soil and vegetation were analyzed by means of gamma spectrometry (employing germanium detectors manufactured by ORTEC, with a relative efficiency of 25% and a resolution of 1.85 KeV, coupled up to a multi-channel analyzer with 8192 channels). As could be determined in our investigations, the main source of activity is natural 40K (in all samples including water, but due to different concentrations at the source, the measured activity is also different). Significant activity concentration values were yielded by 238U, 226Ra, and 214Bi, with different amounts in total activity being determined in different samples. Also discussed in this paper are some useful applications of the coal combustion by-products (CCBs) which otherwise rapidly accumulate and cause enormous problems in the environment. (orig.)