Fig. 3

Histopathology of the lung on 28 and 90 days following exposure to 54 μg particles collected at a non-commercial airfield (JEP) and at the apron of a commercial airport (CAP). The sections were stained with HE. Control: Section of lung from a control mouse instilled with water only. A and B: Particles were not readily apparent in mice instilled with JEP and no significant pathological changes were found on day 28 or 90. C: In mice instilled with CAP, some particles were visible in macrophages. D and E: Pronounced eosinophil infiltration and eosinophil vasculitis was observed on day 28 and 90, characterized by infiltrates in the perivascular region and smooth muscle hyperplasia. F-H. Day 28 and 90. Lung sections of mice exposed to 162 μg NIST2975 had visible particles and particle-loaded macrophages, along with modest inflammation-related changes