Preliminary investigation of radon concentration in drinking water in 31 cities of China / 中华放射医学与防护杂志

ABSTRACT

Objective:To obtain the distribution characteristics of radon levels in drinking water in cities of China and analysis their influencing factors.Methods:A total of 31 cities were selected and 406 tap water samples were collected in accordance with the sampling plan based on administrative division. Radon concentrations in the water samples were determined by using RAD7 H 2O measuring devices, and the closed loop liquid-gas balance method and grab method . The radon concentrations in the gas loop were measured by using semiconductor detector. After four measurement periods, radon concentrations in water were calculated. Results:The arithmetic mean of radon concentrations in drinking water from 31 cities was (4.92±9.44) Bq/L and the geometric mean (0.71±7.77) Bq/L, ranging from less than the lower detection limit (LLD) to 43.15 Bq/L. For 84.2% of drinking water samples, radon concentrations were less than US EPA recommended 11.1 Bq/L, all lower than the EU-recommended value of 100 Bq/L.Conclusions:The radon concentrations in drinking water are higher in northeastern, northwestern, southwestern, northern China than those in southern, central China and eastern China. The factors influencing radon concentrations in drinking water are closely related to geological structure and water source type. Compared with the global values, the radon concentrations in drinking water in our cities are low and safe in general in China.