However, different source-apportionment methods usually produce similar main sources, although, for example, traffic is a more difficult source because of lack of unique elemental tracers (Thurston et al. 2005).
A workshop was held by the PM Centers to compare different methods for source apportionment of PM.
With regard to the health effects apportionments to the different source components of PM2.5, the between-source variation in daily mortality RR was significantly larger than the between-research group variation in reported RRs.
These and similar multivariate techniques, described and documented in more detail in Hopke et al. (in press), have been applied by the different research groups to achieve source apportionments of the Washington and Phoenix PM2.5 data sets (Table 2).
Allocation of resources, apportionment of productive assets among different uses.
Even though this picture varies greatly between regions, similar particle source apportionments have been reported by different studies carried out elsewhere [30, 31].
"My point in the speech was that insisting on an approach that would purport to guarantee such a goal - essentially by dividing up carbon rights to the atmosphere - will only lead to stalemate given the very different views countries would have on how such apportionment should be made.
Using a different strategy, individual incumbents sometimes seek to influence the apportionment process to give themselves districts with no substantial opposition.
In the fields of pollution sciences (air or water), source apportionment models aim to re-construct the emissions from different sources of pollutants based on ambient data registered at monitoring sites [32].
The application of different multivariate statistical techniques such as cluster analysis, principal component analysis, source apportionment by multiple linear regression on absolute principal component scores for interpretation of the complex databases offers a better understanding of water quality in the study region.
