translation or another mechanism unrelated to exposure-induced reproductive anomalies.
In consultation with Dr. Sanford S. Leffingwell (Special Programs Group, Center for Environmental Health, Centers for Disease Control, U.S. PHS) the committee attempted to estimate the power of the Yamakido and colleagues (1985) study to detect induced mutations in the offspring of exposed workers. Of the 456 subjects, 87 were children of workers with the highest likelihood for exposure, 75 were children of workers with intermediate likelihood for exposure, and 294 were children of workers with relatively low likelihood of exposure. The results suggest that an effect could be detected with reasonable probability only if the mutation risk were increased at least 100-fold in the least-exposed group (i.e., from 10-6 to 10-4) or 1,000-fold in the smaller, more-exposedgroups (i.e., from 10-6 to 10-3). Thus, the Yamakido study did not evaluate a sufficiently large sample to detect induced mutations in the offspring of exposed workers of the Okuno-jima war gas factory.
One additional report suggests that sulfur mustard may be responsible for the induction of cleft lip and palate in the offspring of exposed parents. Taher (1992) studied 21,138 live births at Najmeia Hospital in Tehran between 1983 and 1988, following the use of sulfur mustards in the Iraq-Iran conflict. He asserts that parental sulfur mustard exposures were associated with 30 of the 79 cases of cleft lip and palate that were recorded among newborns in this hospital during this period. No actual exposure data exist, although parents were questioned about their exposure to mustard gas, as well as any family history of clefts, rubella during pregnancy, dietary deficiency, and drug use during pregnancy. No information is presented regarding whether mustard exposure was maternal or paternal or both. It is also unclear if the population captured by this hospital represents the geographic area of heaviest mustard exposure during the Iran-Iraq conflict. Further, it is unclear if this incidence of clefts is truly elevated relative to other regions in this country or other parts of the world. Therefore, this study is hardly definitive. It appears to contain, however, the only other human data that attempt to address the reproductive toxicity of sulfur mustards.
It should also be noted that other animal studies have shown that the structurally similar nitrogen mustards are potent teratogens (Danforth and Center, 1954; Haskin, 1948; Murphy et al., 1958; Sanyal et al., 1981).
Data exist on the reproductive toxicity of sulfur mustards in more than one animal species, but it would be useful to have additional studies to examine the extent of the variability between species. More inhalation and cutaneous exposure studies would also be very helpful,