Postnatal effects of maternal exposure to nitrogen dioxide.

Pregnant albino rats were exposed to nitrogen dioxide in concentrations of 0.05, 0.10, 1 and 10 mg/m3 for 6 hr each day throughout gestation. Postnatal viability, growth, physical maturation, neuromotor development, and biochemical parameters indicative of NO2 oxidizing effects were studied in progeny up to the age of 3 months. It was found that although viability and physical development were little affected (only at 10 mg/m3), dose-dependent neurobehavioral deviations (such as disturbances in early neuromotor development, coordination deficits, retarded development of locomotion, reduced activity and reactivity) were induced by the lower exposures. The reduction in motor activity was found to persist into the postweaning period.