My own experience with fertility issues was that my sperm count was down
over 50% and I was unable to produce a pregnancy. A minor operation to
improve the blood flow restored my sperm count and my ability to produce
pregancies is no longer in doubt. My urologist asserted that it is very
common for a 50% reduction in sperm count to have this effect, since the egg
must be swarmed by sperm before one can penetrate.
I therefore would expect that if we indeed had a drastic reduction in the
sperm count of men in Europe and North America we would have an even more
dramatic reduction in birth rates. Contrary to this prediction, in North
America birth rates are up slightly in recent years.
This being said, I drink bottled water when I am in a town which gets its
water from a river.