Particulate Matter (PM) in ambient air has consistently and coherently been associated with serious human health effects. The new EU air quality standards have, for the Dutch government, led to a number of questions concerning current levels, particle size and chemical composition of PM in the Netherlands, along with the sources influencing the Dutch ambient PM levels.
In 1998 and 1999 measurements were performed at six sites in the Netherlands. We measured PM10, its fine and coarse fractions, the secondary inorganic aerosols, elemental and organic carbon, tracers for sea salt and the elemental composition of aerosol. One conclusion of this study is that there is no significant difference between measured PM10 concentrations and modelled PM10 concentrations in combination with the contribution of natural sources.
The average fraction of model estimates and measured concentrations is 0.94 or 0.91 (depending on the correction factors). Taking the uncertainty in the various estimates into account, we found a 1-s confidence limit of +- 0.20 for the fraction . After combining model calculations and results from this study to get an impression of what abatement could achieve, we found the maximum level of PM10 that can be influenced by domestic abatement measures within the Netherlands to be highly variable: from to 6 to 18 ug/m³. The maximum level of PM10 that can be influenced by foreign abatement measures (EU) varies from 10 to 15 ug/m³. The PM10 in the Netherlands from a natural origin is estimated at between 7 and 9 ug/m3. All these figures are indicative.