It seems that is a general consensus that factors including the huge increase in weight of men, over the past several decades, and the fact that chemicals are now showing up in the urine of men, esp. in America are contributing factors. There isn't a specific bullet, but many scientists agree that it seems to be a combination they think of chemicals primarily, fertilizers and the like, and weight contributing the most....
The story also had several things you could do to try to limit your exposure to some of the chmeicals which have been mentioned repeatedly in the article, and yes, even SEX TOYS were mentioned
A key way to combat the testosterone loss was mentioned as keeping your weight down, lifting weights/exercise, and the story also talked about testosterone therapy and how they can help if your levels are low....there was also a mention that they are finding some reproductive damage now showing up in men around the world, including urethras in some strange locations of the penis.....so I found this to be a pretty disturbing yet really important story.....
I would recommend this story highly. It was on page 182 of the Sept. issue. Has Jamie Foxx on the cover....