千岛湖供水对杭州市主城区饮用水中总放射性水平的影响

Impact of water supply from Qiandao Lake on gross radioactivity level in drinking water in downtown Hangzhou

目的:调查分析千岛湖成为杭州市主城区水源前后,杭州市饮用水中的总放射性水平。方法:自2012年起,每年分别在丰水期和枯水期采集杭州市主城区的水源水、出厂水和末梢水,测定总 α总 β放射性活度浓度并进行比较分析。 结果:2012—2020年杭州主城区3类水样总放射性活度浓度均低于《生活饮用水卫生标准》(GB 5749-2006)规定的限值,3类水样在丰水期和枯水期监测结果比较差异无统计学意义( P>0.05);千岛湖湖水中总 α(0.008±0.000)、总 β(0.034±0.013)放射性活度浓度均小于钱塘江下游段和东笤溪,差异具有统计学意义( Z=-3.235, -4.058,-2.181,-4.577, P<0.05);千岛湖供水前后,杭州市主城区的出厂水和末梢水中总 α总 β放射性活度浓度差异无统计学意义( P>0.05)。 结论:2012—2020年,杭州市主城区饮用水中总放射性水平较低,处于安全水平。千岛湖水总放射性水平低于钱塘江下游段和东苕溪,千岛湖成为主要水源后,未对杭州市主城区饮用水中总放射性产生影响。

Objective To investigate the levels of gross radioactivity in drinking water in Hangzhou city before and after Qiandao Lake as the water source to the main urban area of Hangzhou.Methods Since 2012,water samples were collected from water source,factory water and peripheral water in rainy and dry seasons,respectively,to determine their grossαandβactivity concentrations for comparison and analysis.Results The gross radioactivity levels in drinking water in Hangzhou are lower than the limits specified in the national standard"Standards for drinking water quality"(GB 5749-2006),without statistically significant difference for these water sources between the rainy and dry season(P>0.05).The grossα(0.008±0.000)and grossβ(0.034±0.013)levels in Qiandao lake were both less than those in Qiantang river(Z=-3.235,-4.058,P<0.05),with significant difference(Z=-2.181,-4.577,P<0.05).There was no significant difference in grossαand grossβin factory water and peripheral water before and after the operation of Qiandao Lake water supply project(P>0.05).Conclusions The gross radioactivity in drinking water in downtown Hangzhou are low from 2012 to 2020.The gross radioactivity levels in Qiandao Lake are lower than in the lower reaches of Qiantang river and Dongtiao steam.No impact was generated on radioactivity levels in drinking water after Qiandao lake supplied water to Hangzhou.