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Characterisation Method Information
Characterisation Method Name:
NOx impact on NEX
Date Completed:
Principal Method Name:
EPS: eutrofication pathway and secondary particles pathway
Method Description:
NEX is Normalised EXtinction of species.

Model 1, eutrofication pathway

The characterisation factor is determined by an empirical method.

Approximately 10% of the red-listed species in Sweden are endangered due to eutrofication (Swedish faunavårdkommitte, 1988). This figure is used as a global average and assumed to be relevant for the contribution to extinction of species during 1990, i.e. the category indicator value in the system considered is 0.1 NEX.

In the Baltic Sea region, only a third of the nitrogen is estimated to come from air. Using the same NOx emission estimate, the contribution will be 0.33* 5.56E-12 =1.83E-12 per kg NOx. The same contribution (33%) is assumed to be relevant for deposition on land where the rest is due to N deposition on land, i.e. fertilisation.

Calculation of pathway specific characterisation factor

0.1* 1.83E-12 = 1.83E-13 NEX per kg NOx

Model 2, secondary particles

The characterisation factor is determined by an equivalency method using PM10 as a reference.

As for Severe morbidity of EPS for NOx, the equivalency factor is 1.0.

The characterisation factor of PM10 for NEX is -1.08E-13 , giving a characterisation
factor for NOx that is 1.0*(- 1.08E-13 ) = - 1.08E-13 per kg NOx.

Literature Reference:
Steen B (1999b): A systematic approach to environmental priority strategies in product development (EPS). Version 2000 – Models and data of the default method CPM report Chalmers University of Technology Sweden
Methodological Range:
The residence time in air in the order of a week and the residence time in soil is less than a year. The flow group is emissions anywhere on the globe during 1990. The environmental system investigated is therefore chosen to be global during 1990.

Existing Characterisation Factors of NOx impact on NEX
Characterisation Parameter Category Indicator Impact Indication Principle Aspect Substance Quantity Unit Notes
CFactor NEX EPS/2000
Type = Emission
Direction = Output
Media = Air
Geography = *
NOx 7.50E-14 NEX/kg 2 pathways