On the relation between daily exceedances and yearly averages for PM10
conference paper
The daily limit value for particulate matter (PM10), which limits the number of days with PM10 concentration levels exceeding 50 ?g/m3, is in practice much more restricting than the yearly average limit value. The Dutch system for assessing Urban air quality primarily relies on a simple model that calculates yearly average concentrations only. It is therefore important to understand the relation between yearly average concentrations and the accompanying number of exceedance days. Here, we present a simple analytical expression to describe the relation between the yearly averaged PM10 concentration and the number of days with average concentrations exceeding 50 ?g/m3. This analytical expression, which comprises a two-parameter error function, is based on the assumption of a three-parameter log-normal distribution of the PM10 concentration data. It has been tested in depth using daily averaged PM10 concentrations from measuring stations in the Netherlands and, in less detail, using yearly averaged PM10 concentrations from European countries, as available in the Airbase database. Although the fitted parameters in the relation vary significantly between countries, the resulting values for the so-called 'critical' PM10 concentration, i.e. the yearly averaged concentration that corresponds with the EU-norm of 35 daily exceedances per year of a threshold of 50 ?g/m3, are not dissimilar among these countries. In fact, the 95% confidence interval for almost all countries for which there were sufficient data contains a European average of the critical PM10 concentration of 30 ?g/m3.
Topics
Log-normal distributionParticulate matter (PM10) exceedance daysAir qualityAtmospheric movementsNormal distributionAnalytical expressionsAverage concentrationConfidence intervalEuropean CountriesLog-normal distributionMeasuring stationsParticulate MatterPM10 concentrationParticles (particulate matter)
TNO Identifier
954295
ISBN
9789608965
Publisher
University of West Macedonia
Source title
HARMO 2011 - Proceedings of the 14th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, HARMO 2011, 2 October 2011 through 6 October 2011
Editor(s)
Andronopoulos, A.
Bartzis, S.
Syrakos, J.G.
Bartzis, S.
Syrakos, J.G.
Pages
283-287
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