We wrote about this last summer when two key papers were published almost simultaneously. Together they raised big questions about the future of human fertility.
One, led by Hagai Levine and Shanna Swan, reported that men's sperm counts had declined by more than 50 percent from 1973 to 2013, with no sign that the decline is slowing.
In this article, New Scientist provides a good description of their work. The other, with lead and senior authors Tera Horan and Patricia Hunt, respectively, showed that fetal exposures over three generations of mice to an endocrine disrupting chemical known to suppress sperm count compounded the effects from one generation to the next.
In an interview about these two papers Prof. Fred vom Saal, an expert on endocrine disruptors (and not a participant in either), voiced a deep concern that humans may be in a "fertility death spiral."