ditto what CBS said about pH. this means you shouldn't bleach your nalgene either.
however, this is not something to get your hair mussed about. if you wash correctly, and refrain from drinking that year-old nalgene water, you'll be A-OK even if you're pregnant. leaching takes time, and if you refill your bottle with fresh water and drink it within a reasonable time (don't really have an exact answer, probably hours or days) then the concentration won't be high enough to worry about.
if you're not prego, there has been zero ill effects documented as far as I know.