Chemistry Reference
In-Depth Information
north-west of Europe is an example where problematic “hot spots” are found in
urbanised and industrialised agglomerations.
In addition to the strength and location of local, regional and continental
emission sources, levels and chemical composition of ambient PM depend on
climatology, trajectories, rain scavenging potential, recirculation of air masses,
dispersive atmospheric conditions and geography (proximity to coast or arid
zones, topography, soil cover). These factors largely differ over Europe. Reduction
measures in one region may therefore not be optimal for other regions. In the design
of a meaningful abatement strategy, one needs therefore to take into account the
changing characteristics of PM, or more specifically, one should assess which
anthropogenic and natural constituents build up the particulate matter, to what
extent they contribute to the total mass and where they come from.
To answer these questions, we elaborated three PM data sets bearing chemical
information that recently became available in the Netherlands, Germany and
Belgium. In addition, a first-order quantitative estimate is given of the ratio between
natural and anthropogenic PM10 mass; this ratio defines the “playing field” of
policy-decision makers. To end, a modelling exercise is described comparing the
major emission sources for north-western Europe (here defined as the three
abovementioned countries) with those of the Iberian Peninsula.
2 Concentrations and Chemical Composition at Urban
and Rural Sites
2.1 Data Sets
During the last decade, a considerable number of studies have focussed on the
speciation of PM in different regions of Europe (e.g. [
2
-
7
,
29
]). Recently, dedicated
measurement campaigns were carried out in north-western Europe: “CHEMKAR”
(Belgium) by the Flemish Environmental Agency [
8
], “BOP” in the Netherlands
within the framework of the Netherlands Research Programme on Particulate
Matter [
9
] and in North Rhine-Westphalia IUTA (Germany).
The respective data sets are used here to illustrate the general chemistry of PM10
in north-western Europe. Always, urban and rural sites have been compared. Some
data features are given in Table
1
. The components of interest are sulphate, nitrate,
ammonium, elemental carbon, organic carbon, sodium, chloride and elements.
2.2 Handling
Chemical analyses of PM samples usually provide a major part of the total
particulate mass collected on a filter. Certain tracers or combination of tracers are
