OSAKA -- The sperm count of the average Japanese male has fallen 10 percent from levels of the 1970s, a group of researchers announced Friday.
The researchers presented their discovery in a report, based on the interim findings of a study covering roughly 6,000 men over a period of 28 years, before a meeting of the Japan Fertilization and Implantation Society.
Team leader Yasuniori Yoshimura, a professor at Keio University, said sperm counts saw greater declines during the 1990s, and research on the reasons behind the trend is expected to continue.
Several research groups in various countries are currently looking into whether endocrine disrupters are affecting the formation of sperm cells. A final report comprising data from 20,000 men is due out as early as this fall.