Despite a long history of wastewater reclamation and reuse in many parts of the world, the question of safety of wastewater reuse is still difficult to define and delineation of acceptable health risks have been hotly debated.

• 尽管废水回收和再利用在世界许多国家都有很长的历史，但废水利用的安全问题始终很难界定，（人们）可接受的健康风险情况也始终出于热烈讨论中。