The likely specificity between the circumstances of exposure to harmful agents and reproductive consequences was discussed. According to the authors, exposure to toxic agents or conditions such as cigarette smoke and irradiation may affect human reproduction in a variety of ways. The "circumstances of exposure" include the exposed individual (mother, father, fetus), and the time, duration, level, and route of the exposure. The consequences of the exposure may include infertility, lowered fecundity, chromosomal defects in germ cells or zygote, gene mutation, spontaneous abortion, fetal death, or malformations. This variety of adverse outcomes is considered to result from more than one pathway and different time frames. Selected literature studies concerned with pre and post conception exposure to radiation or tobacco smoke were discussed. It has been found that exposure to high dose x- irradiation in young women may cause temporary amenorrhea and temporary infertility, but in older women permanent infertility may be the result. The results of another study suggest that females who are exposed to radiation in-utero show precocious fecundity. Smoking appeared to increase the length of time taken to conceive a pregnancy, but not all studies agreed. Irradiation exposure during pregnancy may cause microcephaly, growth retardation, fetal death, and possibly development of childhood leukemia and other malignancies. Smoking during pregnancy may cause growth retardation. The authors conclude that although many adverse outcomes are noted, the biological mechanisms behind them are poorly understood.
Proceedings of a Symposium on Epidemiology and Health Risk Assessment, Columbia, Maryland, May 14-16, 1985, Centers for Disease Control/NIOSH, 24 pages, 31 references