Most Americans are increasingly interested in issues of purity, aren't we? We want to drink pure water. And there is a legitimate, growing concern about the quality of our groundwater. We want to breathe clean air. So Congress has passed (on our behalf) stringent Clean Air Acts. We want to consume pure foods. "Natural" foods are big sellers right now, aren't they? So much so that one supermarket, probably selling foods with preservatives and additives, still calls itself "Purity Supreme."

We would like our homes to be free from contaminants, too, wouldn't we? So we may be disturbed by reports like the one where an expert declared that "indoor air quality is ten to one hundred times worse than the air outdoors" (William M, Vaughn, principle scientist at Nauset Environmental Services, quote…