中文摘要：

目的 测定杭州市城东、城南、城北以及下沙4个方位自来水样的总硬度,并分析对人体健康的影响.方法 参照国家标准GBT 5750.4-2006 生活饮用水标准检验方法,即EDTA络合滴定法.结果 各水厂水样总硬度分别为：城东57.86mg/L、城南53.71mg/L、城北93.42mg/L、下沙59.05mg/L.结论 杭州自来水符合我国〈生活用水卫生标准〉中的总硬度不大于450mg/L的标准.但非最适宜的硬度范围内,应多食含钙、镁高的食物.

英文摘要：

Objective To quantitatively determine the total hardness of the running water in Hangzhou and analyze its influence on human health. Methods In the light of GBT 5750.4-2006 national standard for drinking water testing methods, EDTA complexometric titration was employed. Results The total hardness of the four samples taken from the eastern, southern and northern city and Xiasha was 57.86,53.71,93.42 and 59.05 mg/L respectively. Conclusion The total hardness of the running water in Hangzhou is in line with our national standard,but it is not within the most suitable hardness range. Therefore, residents should eat foods with high calcium and magnesium.