Nitric oxide (NO) is a gas produced mainly during combustion processes, such as those occurring in vehicle engines and industrial activities. It is part of the nitrogen oxides (NOx) group and plays a role in the formation of other pollutants, including nitrogen dioxide (NO₂) and ozone (O₃).
While NO itself is less harmful than some related compounds, its presence indicates active pollution sources, particularly traffic emissions. Monitoring NO can help identify areas with increased combustion-related pollution and provide insight into overall air quality dynamics.