Before I go to my main question, this one intrigues me a bit, in the fact that the definition of virtual elimination applies only to substances released as a result of human activity. Could you give me a bit of background in terms of why substances must be released as a result of human activity rather than being found in nature? Is it that we don't deal with that in any way, or that it's a different matter altogether? I don't know if a departmental official wants to respond to this.
On October 24th, 2006. See this statement in context.