Buckstones:
Nitrous Oxide is N2O. The exhaust gases that are blamed for acid rain, smog and breathing problems are described as ‘NOX’, a mixture of Nitric oxide, NO and Nitrogen Dioxide NO2. These react with water to form Nitric acid, whereas Nitrous Oxide is what paramedics give you mixed with air for pain relief, so obviously not that harmful.
In which case Biking has possibly confused the two different compounds in the form of NO2 and N20 ?.Easy mistake to understand.