[Icybee]

If you cycle through areas with a lot of traffic, could the water end up contaminated with vehicle exhaust?

[e12e]

I'm pretty sure most harmful exhaust would be more harmful when breathed in, than when drunk?

[mikeash]

In the same concentrations, I'm sure that's true, but the collection process will also concentrate pollutants quite a bit.

[notfoss]

Sorry to be pedantic, but if you are pretty sure, then how come you end your sentence with a question mark?

[iterationx]

You don't sound sorry.

[neals]

I didn't hear any sound at all.