In August 1991, measurements of mercury levels in fish caught in several U.S. lakes prompted officials in 20 states to warn consumers against eating fish from those waters.

• 1991年8月，对取自美国的几个湖泊中的鱼进行了汞含量测定，结果促使20个州的政府官员警告人民不要食用从这些水体中捕获的鱼。