"On the periodic table of elements, the chemical symbol for mercury is Hg, from the Latin word - Hydrargyrum - meaning liquid silver. For quite some time, we have known that high concentrations of mercury can be toxic to humans; the first account of mercury poisoning was recorded as early as 50 B.C. Today, we recognize that mercury is a neurotoxin and that high levels of exposure can lead to serious illness and, in extreme cases, death. Since the 1950s and 1960s, a growing body of scientific evidence has suggested that mercury emissions from human activities, called anthropogenic emissions, are having widespread impacts on environmental and human health."
January 1, 1970
https://en.wikiquote.org/wiki/Mercury_(element)