An epidemiologic surveillance program for evaluating occupational reproductive hazards.

A noninvasive and inexpensive epidemiologic program for evaluating the possible effects of occupational exposures on fertility is proposed. This surveillance program utilizes reproductive information obtainable from a short questionnaire (1-2 pages in length) or directly from existing medical, employment, or insurance records, and results can be generated readily on a routine basis. This program examines the reproductive experience of the exposed workers in terms of live births compared with that of the US general population with the proper statistical adjustments. It calculates the standardized birth ratios (SBR), adjusting for maternal age, parity, calendar time, and race. Such an analysis will detect whether there is a significant decrease in fertility among a group of employees, and is, therefore, a useful surveillance tool. The proposed method should be viewed as a mechanism to provide an early signal for any potential hazard and to direct priority for other more in-depth epidemiologic or physiologic studies. The procedure is illustrated with data from individuals exposed to EDB, DBCP, and waste-water treatment plant processes. The method can be modified to compare the reproductive performance of an exposed group to that of an internal control group. With an internal control group, additional confounding factors can be taken into consideration. The relative merits of this approach compared to another method of fertility evaluation, semen analysis, are discussed.