Secondary Logo

Journal Logo

Trihalomethanes and Semen Quality in England and Wales

Iszatt, Nina*; Nieuwenhuijsen, Mark J.*†‡§; Bennett, James*; Povey, Andrew; Pacey, Allan**; Moore, Harry**; Cherry, Nicola††; Toledano, Mireille B.*

doi: 10.1097/01.ede.0000362659.30996.d9
Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25–29, 2009: Symposium Abstracts

*Imperial College London, London, United Kingdom; †Center for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; ‡Municipal Institute of Medical Research Foundation (IMIM), Barcelona, Spain; §Center for Biomedical Investigation Network of Epidemiology and Public Health (CIBERESP), Barcelona, Spain; ¶University of Manchester, Manchester, United Kingdom; **University of Sheffield, Sheffield, United Kingdom; and ††University of Alberta, Edmonton, Alberta, Canada.


Back to Top | Article Outline

Background and Objective:

Disinfection by-products (DBPs) have been associated with adverse semen outcomes in laboratory animals. Of the DBPs, there is stronger evidence for the bromo- and chloro-acetic acids, while that for trihalomethanes (THMs) is heterogenous. However, two small epidemiological studies have found no association between DBPs and adverse semen outcomes in humans. In a large case-control study, we investigated the association between individual and total trihalomethanes (TTHM) and low motile sperm concentration (MSC) in six water regions in England and Wales between 1999 and 2002.

Back to Top | Article Outline


Men were recruited from 13 fertility clinics in 9 centres across England and Wales between 1999 and 2002. THM concentrations in water zones were linked to data on semen quality for 647 cases and 936 controls, based on the men’s residence at the time the semen sample was obtained. Low MSC was calculated relative to time since last ejaculation. TTHM levels were categorized as low (< 35.71 μg/l), medium (35.71–49.86 μg/l), or high (49.87–95 μg/l).

Back to Top | Article Outline


Preliminary analyses using a crude measure of THM exposure (annual average THM) found no increased risk associated with TTHM. There were some excess risks found with the individual THMs.

Back to Top | Article Outline


Our preliminary findings are inconclusive. Further analyses will use quarterly THM exposure data weighted to the time of sampling for more precise exposure, and adjust for potential confounders.

© 2009 Lippincott Williams & Wilkins, Inc.