According to researchers, the sperm counts of European and American men have been steadily falling over the last 50 years.

Scientists believe environmental factors are contributing this decline. Warm baths, nicotine and alcohol have always been sperm killers, but new threats such as the heat generated by a cell phone placed in a pocket or a notebook computer placed in the lap are also impacting sperm quality, as well.

So are hair loss medications, steroids and, according to a recent study, Bisphenol-A, a popular type of plastic used in many household goods.

Doctors suggest men be mindful of these threats to their sperm counts. There are currently 8 million couples in the United States who have fertility problems, and it estimated these troubles steam from the man about half of the time.

[CBS Miami]