This molecular epidemiological study investigated the adverse effects of 4-nonylphenol (NP) exposure on the reproductive health in human. With informed consents, 67 couples with complains of male infertility recruited in this study at a clinic in Hsinchu. Among them, 67 couples provided urine samples after 8-hour fasting for NP exposure determination and 67 men provided semen specimens for the sperm exam. Each participant completed a self-reported questionnaire for information on socio-demographic characteristics, and life and diet styles. The results showed that urinary NP levels (log NP, .mu.g╱g creatinine) were significantly associated with sperm counts (r=0.685) and sperm activity(r=0.701) of semen. The increase of log average urinary NP level can cause sperm counts and sperm activity of semen descend. This study demonstrates the possibility that infertility in men may be associated with the NP exposure.
