No studies were identified in humans that investigated reproductive or developmental effects after inhalation exposure to zinc compounds. Pathological examination 17 mo after exposure of rats, guinea pigs, and mice to zinc oxide/hexachloroethane smoke (1 hr/d, 5 d/wk for 20 wk) did not demonstrate any treatment-related abnormalities in mammary glands, ovaries, or fallopian tubes (Marrset al. 1988).

Reproductive effects of boron compounds have been investigated after occupational exposure. The number of live births in employees at a boron mine was not statistically different than the number of live births in the general U.S. population (Whorton et al. 1994). However, that study has been criticized because of its limitations and a lack of sensitivity (Moore 1997). A study (Tarasenko et al. 1972), summarized by Moore (1997), found a decrease in sexual activity in 28 workers exposed to very high concentrations of boron (10 mg/m³). Examination of the semen from six of the workers demonstrated a reduction in semen volume, a decrease in the number of spermatozoa, and decreased sperm motility.

No studies were identified that investigated the carcinogenicity of boric acid.

Excess lung cancer mortality was detected among persons living in an abandoned zinc/lead mining area in the midwestern United States as compared with state and national age- and sex-specific lung cancer rates (Neuberger and Hollowell 1982). However, potential confounding factors (such as smoking) were not controlled for.

Logue et al. (1982) investigated mortality among a cohort of 4,802 male workers from two zinc and seven copper refining plants. Overall mortality and death from specific cancers were not elevated for the whole cohort. Cancer mortality rates, however, were not computed separately for the 978 zinc refinery workers.

Marrs et al. (1988) found that female mice, but not female rats or guinea pigs, exposed to 1.3, 12.8, or 121.7 mg zinc/m³ as zinc oxide/hexachloroethane