Pulmonary toxicity of inhaled nanoscale and fine XXXX particles: mass and surface area as an exposure metric.

@entity137 @entity55 @entity219 @entity1947 @entity35 @entity1948
The total surface area is known to be an effective exposure metric for predicting the lung @entity137 of low solubility nanoparticles (NPs). However, if NPs are dissolved quickly enough in the lungs, the mass may be correlated with the @entity137 . Recent studies have found that the @entity137 of @entity1947 ( @entity1948 ) NPs was caused by the release of @entity219 ions. Thus, we hypothesized that mass could be used as an exposure metric for the @entity137 of @entity1948 NPs. Healthy @entity35 were exposed to a low, moderate, or high dose of 35 and 250   nm @entity1948 particles or filtered air. Bronchoalveolar lavage fluid was collected to determine @entity55 , injury and oxidative stress. The @entity55 induced by @entity1948 particles according to different concentration metrics, including number, mass and surface area, was compared. The mass concentration was significantly correlated with the percentage of neutrophils (R(2)   =   0.84), number of neutrophils (R(2)   =   0.84) and total cells (R(2)   =   0.73). Similarly, surface area concentration was significantly correlated with the percentage of neutrophils (R(2)   =   0.94), number of neutrophils (R(2)   =   0.81) and total cells (R(2)   =   0.76). There was no correlation between the number and @entity55 . We found that both mass and surface area were effective as metrics for the @entity137 of @entity1948 NPs, although only surface area was previously indicated to be an effective metric. Our results are also consistent with recent study results that @entity1948 NPs and released @entity219 ions may play a role mediating the @entity137 of NPs.
