Monitoring of environmental radioactivity in China following the Fukushima nuclear accident

Objective To determine the artificial radionuclides levels in environmental samples collected in some areas of China following the Japanese Fukushima nuclear accident,and to evaluate the extent of radioactive contamination.Methods A total of 118 samples including aerosol,water,soil and biological samples were collected and the activity concentrations of 131I, 137Cs and other artificial radionuclides were analyzed by using high-purity germanium (HPGe) γ spectrometry.Results Artificial radionuclides 131I,134Cs,137Cs and 136Cs were detected in the aerosol samples on 2 April,2011 and the activity concentrations were 1720,247,289,and 23 μBq/m3,respectively.Trace amount of 131I was detected in one sample of rain water and two samples of surface soil with concentrations of 2.08 Bq/L,1.82 and 0.59 Bq/kg,respectively.131I was also detected in 18 vegetable samples which were collected from 2 April to 13 April with the range of 0.55 -2.68 Bq/kg.Neither abnormal concentrations of 131I nor 137Cs was detected in milk,drinking water,sea water and marine products samples.Conclusions During the Fukushima nuclear accident,although minute quantities of radionuclides were detected in some samples collected in China,the effective dose for adults attributed to the nuclear accident is extremely small and significantly below the level that could cause harm to the public. Key words: Fukushima nuclear accident;  131I;  137Cs;  γ spectrometry