Re: Are you certain?
Go ahead and filter the water BEFORE you distill it, not a bad idea. It's true that there are chemicals that evaporate and condense again. But I think you're talking about seriously poluted water like right out of the chemical plant.
I've been drinking distilled water since 1971. I know thousands of people that drink distilled water, never have I heard of even one contamination from chemicals evaporating and condensing into their water distillers. So although it may be technically possible, if you want to worry about it go ahead.
I live in the country and worry about the farmers pesticides getting in the water. City folks have all kinds of contaminates in their water. Distilling is the best way to go. If the water is so bad you can smell the chemicals in it find another water source, or filter the hell out of it, or reverse osmosis it, before it goes into the distiller. And if you still don't feel save have the water tested before and after you distill it. I believe there's companies that go around and do that free. You know, an advertised "special", "Get your water tested free to see if you need the latest reverse osmosis system".
Ideally, distill the water after it's been through a reverse osmosis system. But I still feel if you filter it AFTER you distill it you greatly increase you chances of contamination.
Doc Sutter