Pulmonary oxygen toxicity is caused by divers exposing themselves to elevated partial pressures of oxygen for long periods of time, and is primarily a concern for technical divers who decompress on oxygen. Pulmonary oxygen toxicity causes a burning sensation in the trachea, coughing, shortness of breath, and eventually lung failure.
Pulmonary Oxygen Toxicity (PO) and Central Nervous System Toxicity (CNS)
oxygen
Partial pressure of oxygen of 1.6 will cause toxicity. If using standard air (roughly 20% O2) this equates to a pressure of 8 bar which is present at 70m. In terms of the percentage of O2 which causes toxicity, it depends on the depth but a partial pressure of 1.6 bar is the toxicity threshold
Abnormally slow breathing is a symptom of oxygen toxicity
airway inhalation
The pulmonary artery carries oxygen-poor blood. The pulmonary vein carries oxygen-rich blood.
Oxygen itself is not toxic, as it is essential for life. However, breathing in pure oxygen at high concentrations for extended periods can be harmful and lead to oxygen toxicity, causing lung damage and other health issues.
The pulmonary artery carries oxygen poor blood and the pulmonary vein carries oxygen rich blood.
Pulmonary vein
The pulmonary veins carries oxygen rich blood from the lungs to the heart.
The following are some dangers of smoking; tar, and carcinogen substances causes cancer, smoking reduces oxygen in the body, and it also causes pulmonary disorders.
Oxygen enters the pulmonary blood in the capillaries of the alveoli -- the air sacs of the lungs.