Objective To compare the differences of serum mineral element levels in rats feeding with purified water(PW), filtered tap water(FTW) and boiled tap water(BTW) respectively for a long term.

• 目的 比较长期饮用纯净水、净化水及自来水 (煮沸并冷却 )后 3组大鼠血清中常量及微量元素水平的差别。