Monitoring and analysis of radioactivity levels of environment samples and foods in Nanjing

Objective To obtainthe baseline data of the gross α and gross β radioactivity levels in environmental samples and foods by the monitoring and analyzing the radioactivity levels in drinking water, aerosols and commercial foods in Nanjing City. Methods 15 types of samples, including water source, produced water, aerosol, chicken, pork, stalk vegetable, root vegetable, fresh milk, leafy vegetable, flour, fruits, rice, tea, fish and crab were collected. After pretreatment, LB4008 four-channel low background α and β measuring instrument was used to measure the gross α and gross β radioactivity concentrations. Results The gross α and gross β activity concentrations of source water and produced water in Nanjing from 2016 to 2019 were lower than the national limits. The gross α and gross β activity concentrations in the source water were significantly higher than those of the produced water ( P < 0.05). The mean activity concentration range of gross α and gross β in aerosol were 0.16〜0.98 mBq/m 3 and 0.14〜2.15 mBq/m 3 from 2016 to 2019, and with no statistical difference in difference samples ( P > 0.05). The gross α and gross β activity concentration range of foods were 0.10〜17.00 Bq/kg and 22.20〜187.20 Bq/kg, of which the gross α and gross β activity concentration in tea were significantly higher than that of other kinds of foods ( P < 0.05). Conclusion The radioactivity level in drinking water, atmospheric aerosols and foods in Nanjing were not contaminated by radioactive substances, and the gross α and gross β were relatively stable. 摘要： 目的 通过对南京市饮用水、气溶胶及市售食品中总α和总β放射性水平监测和分析, 掌握本市环境介质和食 品中总α和总β放射性水平。 方法 采集水源水、出厂水、气溶胶、鸡肉、猪肉、茎菜、根菜、生鲜牛乳、叶菜、面粉、水 果、大米、茶叶、鱼及螃蟹 15 种样品, 将样品进行前处理后, 用LB4008型四路低本底αβ测量仪测定总α和总β活度 浓度。 结果 2016—2019年南京市水源水和出厂水总α和总β活度浓度均低于国家限值, 水源水中总α和总β活度 浓度均明显高于出厂水中总α和总β浓度活度（ P < 0.05);气溶胶中总α活度浓度范围为0.16〜0.98 mBq/m 3, 总β活度浓度均值为在0.14〜2.15 mBq/m 3,年度差异均无统计学意义（ P > 0.05);食品总α活度浓度范围为0.10〜17.00 Bq/kg, 总β活度浓度范围为22.20〜187.20 Bq/kg, 其中茶叶中总α和总β活度浓度明显高于其他种类食 品( P < 0.05)。 结论 南京市饮用水、大气气溶胶及食品中α和总β放射性水平相对稳定, 未受到放射性物质污染。