In utero and early-life nitrate in drinking water impacts lung function of weanling rats

Consumption of nitrate in drinking water has previously been associated with a range of adverse health effects, including methemoglobinemia and potentially cancer. In animal models, it has been shown to impact respiratory structure and function, however, there is a paucity of data of the effects of in utero exposure on the respiratory health of offspring. In this study, pregnant rats were given drinking water containing nitrate at 50 or 100 mg/L (or control). At three weeks of age, we assessed a range of respiratory health outcomes, including lung function, pulmonary inflammation and lung structure, in the offspring of both sexes. Nitrate exposure was associated with minor adverse effects on lung function, including an increase in airway resistance at functional residual capacity in male offspring, but there were no significant changes in lung structure. Our results suggest that in utero / early-life exposure to nitrates in drinking water at levels relevant to human exposure is unlikely to have significant negative impacts on offspring respiratory health.