Exposure to air pollutants, such as nitrogen oxides NOx and ozone O3 , can have significant adverse effects on the respiratory system of humans. These pollutants can cause inflammation, exacerbate pre-existing respiratory conditions, and even lead to the development of new respiratory diseases. The mechanisms through which these pollutants affect our health are as follows:1. Nitrogen oxides NOx : Nitrogen oxides are a group of gases that include nitrogen dioxide NO2 and nitric oxide NO . They are primarily produced by combustion processes, such as those occurring in motor vehicles and industrial facilities. When inhaled, NOx can cause several respiratory issues: a. Inflammation: NOx can irritate and inflame the lining of the respiratory tract, leading to symptoms such as coughing, wheezing, and shortness of breath. This inflammation can exacerbate pre-existing respiratory conditions, such as asthma and chronic obstructive pulmonary disease COPD . b. Oxidative stress: NOx can generate reactive oxygen species ROS in the respiratory tract, which can cause oxidative stress and damage to lung tissue. This can lead to a decrease in lung function and an increased susceptibility to respiratory infections. c. Altered immune response: NOx exposure can alter the immune response in the respiratory system, making it more difficult for the body to fight off infections and increasing the risk of respiratory illnesses.2. Ozone O3 : Ozone is a highly reactive gas that is formed when sunlight reacts with other air pollutants, such as volatile organic compounds VOCs and NOx. Ground-level ozone is a primary component of smog and can have several detrimental effects on the respiratory system: a. Irritation and inflammation: Ozone can irritate the respiratory tract, causing symptoms such as coughing, chest pain, and shortness of breath. It can also cause inflammation in the lungs, which can exacerbate pre-existing respiratory conditions and increase the risk of developing new respiratory diseases. b. Decreased lung function: Exposure to ozone can reduce lung function, making it more difficult for individuals to breathe and take in sufficient oxygen. This can be particularly problematic for those with pre-existing respiratory conditions, as well as for children, the elderly, and individuals who engage in outdoor physical activities. c. Increased susceptibility to infections: Ozone exposure can impair the respiratory system's ability to remove inhaled particles and pathogens, increasing the risk of respiratory infections.In summary, exposure to air pollutants such as nitrogen oxides and ozone can have significant negative effects on the respiratory system of humans. These pollutants can cause inflammation, decrease lung function, and increase susceptibility to respiratory infections, leading to a range of respiratory symptoms and potentially contributing to the development or exacerbation of respiratory diseases.