Monitoring and risk assessment of total α and β radioactivity levels in drinking water in the nine districts of metropolitan Chongqing in 2019-2021 / 公共卫生与预防医学

ABSTRACT

Objective To investigate the radioactivity levels of total α and total β in drinking water in nine districts of Chongqing City from 2019 to 2021, and to provide reference for the risk monitoring of drinking water in the metropolitan areas of Chongqing. Methods The total α and total β radioactivity levels in water samples were determined by the comparative measurement method and the thin source deposit method in GB/T5750.13-2006 “Standard Examination Methods for Drinking Water-Radiological Parameters”. The monitoring results were assessed according to GB5749-2006 “Standards for Drinking Water Quality” and the fourth edition of the WHO Guidelines for Drinking Water Quality. Results From 2019 to 2021, the total α activity concentration of the water samples measured in the nine districts of metropolitan Chongqing ranged from 0.002 to 0.039 Bq /L, and the total β activity concentration ranged from 0.015 to 0.190 Bq /L. There was no significant difference in the activity concentration (tα=0.545, Pα=0.591; tβ=-1.438, Pβ=0.163>0.05). From 2019 to 2021, the average value of total α radioactivity decreased year by year and its activity value was relatively low, indicating a low health risk. However, the average value of total β radioactivity increased year by year, which should be paid attention to. Conclusion The total α and total β radioactivity in water samples measured in the present study are lower than the standard recommended limits. The estimated annual average effective dose of radiation caused by drinking water is 0.005-0.010 mSv, which is lower than the limit of 0.1 mSv recommended by WHO, and this radioactivity level will not have an impact on the health of residents. However, the total β radioactivity level of the monitoring points in Banan and Shapingba is relatively high compared to other jurisdictions, and further tracking and monitoring should be carried out.