Effect of HBOT on Histopathologic Examinations. Control group demonstrated normal alveolar structure in lung. PQ group demonstrated severe edema, hemorrhage, leukocyte infiltration, and alveolar septal thickening. PQ + HBOT group demonstrated minimal hemorrhage, leukocyte infiltration, and alveolar septal thickening, H&E ×100. PQ, paraquat; HBOT, hyperbaric oxygen treatment.