The clinical manifestations of ozone poisoning are most apparent in the respiratory system, which is the main organ to be affected. Other organs and systems are also affected, such as the eyes and the central nervous system (CNS). The detrimental effects of ozone are due to ozone molecules, as well as its byproducts, including reactive oxygen species (ROS)  . Ozone is present in varying concentrations in both indoor and outdoor air, and exposure to significant concentrations takes place in high altitude flights.
The respiratory symptoms associated with ozone toxicity include coughing, wheezing, chest pain, shortness of breath, chest discomfort and nasal mucosal and pharyngeal irritation. The severity of symptoms and the levels of ozone at which symptoms are elicited vary between individuals. Moreover, the effects of ozone are more marked during exercise. It has been suggested that adults in their second and third decades of life are more prone to the effects of ozone, as well as overweight individuals.
Ozone decreases lung function, both on acute and chronic exposure and it has been shown that repeated exposure precipitates symptoms and worsens already existing complaints. A positive correlation between higher ozone levels and respiratory-related hospital admissions and morbidity has been observed . In the general population, ozone increases the extent to which airways respond to stimuli such as histamine, induces inflammation of the airways and increases the permeability of pulmonary blood vessels resulting in leakage of plasma proteins in the lungs . Individuals with asthma may suffer from more frequent acute exacerbations, as well as an increase in the severity of such events  . Furthermore, they have a lowered tolerance towards triggers that are known to cause asthmatic attacks.
Ozone may cause eye irritation and dryness, and worsen allergic conjunctivitis. Fatigue has been noted as well, along with other neurological symptoms that include headaches and decreased concentration .
A physical exam will confirm the respiratory symptoms reported. There are several modalities that can be used to observe and measure the effects of ozone on the respiratory system, these are:
Serum levels of inflammatory molecules and white blood cells may also be elevated.