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

牙齿斑病主要是无害的牙齿染色，最早在自然高化物地区被观察到。

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

书中也没有对饮水法阐述，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，水化物对儿童蛀牙的预防有明显且重要的效果。

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.

水化物支持者指出了像这样的研究，该研究观察了拿大卡尔里在 2011 年停止在水中添化物后的情况。