Daily News Archive
Sperm Quality Low in Missouri's Agricultural Areas
Dr. Shanna H. Swan, an epidemiologist and research professor of Family and Community Medicine, led a group of researchers who studied 512 couples receiving prenatal care at clinics in Columbia, Mo., Minneapolis, Los Angeles, and New York as part of the ongoing Study for Future Families funded by the National Institutes of Health (NIH). Swan found that semen quality was equally high in Minneapolis and New York, and slightly lower in Los Angeles. However, men in mid-Missouri had counts and quality that were significantly lower than men from any of the urban centers.
"We believe that agricultural chemicals could be contributing to this decrease in semen quality," Swan said. "The county in which our Missouri participants lived is quite rural. In 1997, 57 percent of the land was used for farming, compared to 0 to 19 percent for the other three counties we studied. We are continuing this research and examining the exposure of men to specific chemicals used in farming." Prior studies of semen quality were often conducted in large metropolitan areas. The only other published study on a comparable semi-rural population analyzed semen quality among men in Iowa City, and also found reduced sperm concentration. Swan and her colleagues are now studying semen quality in Iowa City.
Since the 1930s, there has been considerable interest in semen quality as a key predictor of male reproductive dysfunction. However, semen analyses are very sensitive to laboratory methods, the equipment employed, and the nature of the population, all of which may vary from one study to another. The detailed and rigorously applied protocol used by this research team supported the differences between geographic areas after adjusting for other factors known to alter sperm quality such as age, smoking and recent fever.
The study, funded by a $2.8 million grant from the NIH, was conducted in collaboration with researchers at the University of Minnesota, the University of California at Los Angeles Medical Center, the Mount Sinai School of Medicine, the University of California at Davis, and researchers in Denmark and Japan. The study, "Geographic Differences in Semen Quality of Fertile US Males," is available on the online edition of Environmental Health Perspectives, the peer-reviewed scientific journal of the National Institute of Environmental Health Sciences. For more information contact Christian Basi, at (573) 882-4430, BasiC@missouri.edu.
Source: University of Missouri - Columbia.