The methodology involves, for each pollutant, a site-specific impact pathway analysis (IPA)
(analysis of the chain: emission - dispersion - impact - cost)
The main steps of an IPA are illustrated with this picture

impact pathway analysis

To calculate the damage cost of a pollutant emitted by a source,
the impacts are summed over the entire region that is affected (continent)
and over all damage types that can be quantified:

• health
• loss of agricultural production
• damage to buildings and materials
• ecosystem
• etc

Result of an IPA: damage cost in €/kg of pollutant.

For many persistent pollutants (dioxins, As, Cd, Cr, Hg, Ni, Pb, etc)
the ingestion dose can be about two orders of magnitude higher than the inhalation dose

To get €/kWh multiply by kg/kWh for each pollutant and sum over pollutants emitted during power production.

For processes or products that involve several stages, the IPA is combined with a life cycle assessment (LCA)

For example to determine the total damage cost of electricity, one needs an LCA of the fuel chain.

The relation between IPA and LCA is illustrated in this matrix, for the example of electricity production by coal or oil. Ideally each element of the matrix should be evaluated by a site-specific IPA, but most conventional LCA studies first  sum the emissions (of each pollutant) over all stages and then multiply the sum (of each pollutant) by indices of "potential impact". The "potential impact" indices of conventional LCA are not very realistic because they do not model the environmental pathways and dose-response functions. That contrasts with the methodology of the ExternE project series [www.externe.info] that we use, which does  calculate real impacts.

Copyright ©, Dr. Ari Rabl

This page was last updated on 9 May 2007.