The mostly harmless teeth staining was first observed in communities with high natural fluoridation.

齿氟斑病主要齿染色，最早在自然高氟化物地区被观察到。

There is nothing on the fluoridation of water, and too little on nutrition.

书中也没有对饮水加氟法进行阐述，在营养学方面也较少被提及。

The study authors found that prior to 1975, there was a clear and important effect on prevention of tooth decay in children due to water fluoridation.

研究作者发现，在 1975 年之前，水氟化物对儿童蛀防有明显且重要效果。

Supporters of water fluoridation point to studies like this one that looked at what happened in Calgary, Canada, after they stopped fluoride in their water in 2011.

水氟化物支持者指出了像这样研究，该研究观察了加拿大卡尔加里在 2011 年停止在水中添加氟化物后情况。