These studies demonstrate that even short-term inhalation of
CdO NPs can produce persistent pulmonary cell injury and
inflammation, as well as have deleterious effects on lung
organization and systemic immune function. While some
indicators of pulmonary injury were reversible over time,
others persisted for up to one week after cessation of
exposure, suggesting continued damage or lack of repair.
Persistent adverse pulmonary effects, such as those observed
here, represent an important occupational health threat as
engineered metal oxide nanoparticles are being manufactured
and used at ever-greater frequency, (potentially) placing a
large number of workers at risk. Future studies are needed to
identify mechanisms associated with CdO NP-induced pulmonary
injury, as well as the onset and persistence of such
effects.