What is nitrogen dioxide (NO2)?
Nitrogen dioxide (NO2) is one of the six main measured air pollutants. Notably, it is a major contributor to the formation of smog and a precursor to many harmful secondary pollutants including ozone and particulate matter.
Where does it come from?
Nitrogen Dioxide can be formed from both organic and inorganic sources. Organic sources such as lightning, plants, water, and soil, only account for 1% of nitrogen dioxide found in cities. The other 99% is created by inorganic sources such as motor vehicle emissions, unfiltered gas heaters, cookers, and various industrial activities.
How does it affect our health?
Although NO2 is not the most harmful of all the pollutants – it's usually the precursor for pollutants like ozone and particulate matter. High concentration levels of NO2 can cause irritation in the lungs, whilst lowering the resistance to respiratory infection. Increased levels cause more frequent and intense asthma attacks on people that suffer from asthma. Children and the elderly run a much higher risk for experiencing adverse health effects.
NO2 has the ability to chemically transform into nitric acid, and therefore contribute to lake acidification and acid rain. Nitric acid can corrode metals, fade fabric and degrade rubber, whilst also damaging trees and crops, resulting in substantial agricultural losses.