Researchers Worried about Limp Korean Sperm

The sperm of young Korean men is growing weak. Although there is no problem with their sperm count, over the past five years Korean men have produced significantly small numbers of healthy, actively mobile sperm cells. Experts blame the phenomenon on environmental hormones that affect the reproductive system.

Professor Han Sang-won of the Department of Urology at Yonsei University's College of Medicine studied the sperm of 102 students from a Seoul university between April and November last year, and discovered that the average motility rate of the sperm was in the upper 40 percent range.

The motility rate is the percentage of healthy sperm that can reach the female egg; a rate of 50 percent or more is considered healthy by World Health Organization standards.

The motility rate of sperm from 20-something Koreans has been declining for the past five years. From 1999 to 2001 it was an average of 66 to 83 percent. Then it dropped to upper 40 percent in 2002, and has been below normal since.

The sperm that Professor Han's team collected came from otherwise healthy Koreans in their early 20s. The researchers studied soldiers until 2004, athletes in 2005, and normal university students last year.
"The decrease in motility is serious in that it can become the major cause of sterility in men," Professor Han said. Detailed research results will be announced in July.

The researchers also discovered that the sperm count of the same group of university students showed a 30 percent decrease during exam periods, which confirms that stress can cause a temporary decline in the sperm count.