北京市乡镇级集中式饮用水总放射性监测分析

目的 调查2018—2019年北京市乡镇级集中式饮用水中的总放射性水平及分布特点，以便更好的开展水质放射性监测和评价工作。方法 抽查北京市12个行政区共215 件乡镇地下饮用水样品，依据EJ/T 1075—1998《水中总α放射性浓度的测定 厚样法》、EJ/T 900—1994《水中总β放射性测定 蒸发法》进行监测分析。结果 2018—2019年北京市乡镇级集中式饮用水总α放射性水平为0.050（0.052）Bq/L，范围为（0.001～0.210）Bq/L，总β放射性水平为0.048（0.038）Bq/L，范围为（0.002～0.261）Bq/L，所有样品的总放射性水平皆低于我国生活饮用水卫生标准的放射性指标指导值。所有行政区地下水总α、总β放射性水平在2018—2019年分布差异无统计学意义（P > 0.05）；同一时期不同行政区的总α、总β放射性水平分布差异有统计学意义（P < 0.05），潮白河水系的密云、怀柔和顺义较高。结论 北京市乡镇饮用水中放射性本底分布水平，处于正常范围。

Monitoring and analysis of gross radioactivity of centralized drinking-water of township in Beijing

Objective To investigate the distribution of gross α and gross β levels of centralized drinking-water of township in Beijing from 2018 to 2019, so as to carry out better monitoring and evaluating the radioactivity in water.Methods A total of 215 underground drinking water samples were collected from 12 districts of Beijing, then monitored and evaluated according to the Determination of gross alpha activity in water-thick source method EJ/T 1075—1998 and Determination of gross beta activity in water-evaporation method EJ/T 900—1994.Results The gross α level of centralized drinking water of township in Beijing was 0.050 (0.052) Bq/L, ranging from 0.001 to 0.210 Bq/L, and the gross β level was 0.048 (0.038) Bq/L, ranging from 0.002 to 0.261 Bq/L from 2018 to 2019. Gross α and gross β levels of all samples did not exceed the guidance value recommended by standards for drinking water quality. There was no significant difference in the distribution of gross α and gross β levels of samples of all districts from 2018 to 2019(P > 0.05), there were significant differences in the distribution of gross α and gross β levels of samples from different district in the same period (P < 0.05). And the levels of Miyun, Huairou and Shunyi in Chaobai River system were higher than other districts.Conclusion The distribution of radioactive background of centralized drinking-water of township in Beijing was mastered, which was in the normal range.