[Considerations when conducting study of semen indices in workplaces].

The possible adverse impact of environmental chemical exposure on semen quality is a public health concern. However, an epidemiological study targeting the general population is not easy. An alternative approach is to study workers exposed to higher doses of the concerned chemicals, whereas there have been only a very limited number of such studies conducted in Japan to date. This review, on the basis of the author's experience thus far, attempts to shed light on considerations when planning possible semen studies in workplaces in Japan. They include study design, informed consent of both the employer and participating employees, means of increasing participation ratio, control of nonexposure factors such as abstinence period and medical history, standardization in measuring semen indices, interpretation of study results, and necessary precautions when reporting a low semen quality in the exposed population.