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TRIHALOMETHANE LEVELS AND SEMEN QUALITY
Citation:
Fenster, L., K. Waller, G. Windham, T. Henneman, M. Anderson, S. Swan, P Mendola, AND J. Overstreet. TRIHALOMETHANE LEVELS AND SEMEN QUALITY. Presented at 2001 Congress of Epidemiology, Toronto, Canada, June 13-16, 2001.
Description:
Trihalomethanes (THMs) are common byproducts of chlorinating drinking water. The effects of disinfection byproducts on semen quality have not yet been studied in humans, despite animal studies linking exposure to sperm abnormalities. We are currently analyzing the relationship of trihalomethanes to semen quality (concentration, motility and morphology) using two samples collected from each of 157 men. Total THM (TTHM) levels were assigned based on routine utility measurements taken during the 90 days preceding the date of the semen sample (this time interval corresponds to the period of spermatogenesis). We analyzed semen parameters as continuous and categorical variables adjusting for potential confounders such as abstinence, age, and smoking using repeated measures analyses to control for non-independence of samples. We noted a slight increase in sperm concentration with increasing TTHM dose, which may have been due in part to a low value in the reference group (adjusted mean for low TTHM=58.92 ? 6.72 compared to 71.19 ? 6.75 for the high exposure category, p=0.07). We did not observe a relationship between TTHM level and morphology or motility as measured by standard methods. However, a tendency for a decrease in sperm movement characteristics (percent progressive, straight line velocity, and linearity) and a small increase in mean angular deviation with increasing dose was detected using semen parameters from the computer-aided sperm analyses (CASA). For example, the adjusted mean for percent progressive equaled 66.66 ? 1.76 for low TTHM compared to 64.39 ? 1.79 for the high exposure category (p=0.23); for linearity the respective adjusted means were 58.56 ? 0.90 compared to 56.49 ? 0.90 (p=0.03). Since CASA motility parameters have been shown to be associated with fertility, additional research with larger sample sizes and more comprehensive exposure assessments is recommended.
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