Long before the passionate debates over cigarettes, DDT, asbestos or the ozone hole, most Americans had heard of only one environmental health controversy: fluoridation.

• 在人们尚未开始热烈讨论香菸、DDT、石绵和臭氧层破洞之前，大多数美国人只听过一项环境影响健康的争议：饮水加氟。