The effective dose annual limit in European Union member states for doses above natural background is 1 mSv. This includes ingestion, inhalation and external dose to a member of public. For doses received due to ingestion of drinking water, parametric value for annual indicative dose is 0.10 mSv. As the name indicates, parametric value is not a limit value: when the parametric value is exceeded, a risk estimation needs to be carried out. Assessment of health risks is done in various fields, however, it is unclear how to do this for drinking water in a situation where the parametric value for indicative dose is exceeded but the annual effective dose limit is not. Approach for risk assessment through cost-benefit analysis is proposed to find the upper limit for investment in a water treatment plant that is justified for lowering the indicative dose of drinking water to a level equal to the parametric value. When a water treatment process cannot be improved with financial resources equal to or below the upper limit of investment, the risk caused by radionuclide ingestion with drinking water can be considered low enough that it is acceptable for the society as a whole. Case study based on the situation in Estonia is brought as an example.

在欧盟成员国中，高于自然本底剂量的有效剂量年度限值为1 mSv。这包括对公众的摄入，吸入和外用剂量。对于因摄入饮用水而收到的剂量，年度指示剂量的参数值为0.10 mSv。顾名思义，参数值不是极限值：当超出参数值时，需要进行风险估计。对健康风险的评估在各个领域中进行，但是，在指示性剂量的参数值超过了年度有效剂量限值的情况下，如何对饮用水进行这种处理尚不清楚。提出了通过成本效益分析进行风险评估的方法，以找到在水处理厂进行投资的上限，该上限有理由将饮用水的指示剂量降低到等于参数值的水平。如果无法用等于或低于投资上限的财政资源来改善水处理过程，则饮用水中放射性核素摄入引起的风险可被认为足够低，以至于整个社会都可以接受。以基于爱沙尼亚局势的案例研究为例。饮用水中放射性核素摄入引起的风险可以认为足够低，以至整个社会都可以接受。以基于爱沙尼亚局势的案例研究为例。饮用水中放射性核素摄入引起的风险可以认为足够低，以至整个社会都可以接受。以基于爱沙尼亚局势的案例研究为例。