Nitrogen oxide :: All vegetation types

Critical Load/Level Values: 

30 µg NOX (as NO2) m-3 annual mean; 75 µg NOX (as NO2 ) m-3 24-hour mean

Status: 
UNECE 2004
Habitat/Ecosystem Type: 
all vegetation categories
Description: 

The concentration units are referenced as if all the NOX were in the form of NO2. (see Unit Conversion). Nitrogen oxides are known to have greater adverse effects in the presence of SO2 and O3, and hence the critical level should apply where these pollutants are close to their critical level too.

Reliability: 
Uncertainty: quite reliable i.e. the results of some studies are comparable
CL reference: 
Manual on methodologies and criteria for modelling and mapping critical loads and levels and air pollution effects risks, and trends,