"It has been known for more than 10 years that sperm counts had been falling in the western world, with scientists at Copenhagen University pointing to exposure to pesticides and industrial chemicals. "
Pesticides and chemicals have been present in far greater amounts well prior to the last 10 years.
I wonder if the fact that in some Western countries, boys are told again and again not to be 'boys' has something to do with this...
But they didn't have professional sperm counters before then.