By Janet Raloff
Many city dwellers left urban environs for quieter, cleaner lives in farm country. A new epidemiological study suggests that a man’s sperm may pay a subtle price for that rural life.
Researchers previously reported evidence suggesting regional variations in the amount and quality of men’s sperm. However, most of this work didn’t account for smoking, recent sexual abstinence, or other factors that can greatly affect sperm. Moreover, the studies were conducted strictly in big cities.