Volume XI |

Atmospheric Pollution by Iceland Volcano Lava Dispersion – the Brussels Case

Abstract: In April 2010 the Icelandic Eyjafjallajökull stratovolcano emitted large clouds of volcanic ashes that provoked chaotic situations for the air traffic of the Northern hemisphere. The impact of the resulting atmospheric pollution may have widespread effects on the health of the populations living in the affected regions. For this reason, the study of the airborne particles brought by the ash clouds must cover not only their concentrations expressed in μg/m3, but also their size, shape and chemical composition. Our results revealed that during the eruption days, some periods with a higher concentration of the coarse particles (between 2.5 and 10 µm) were observed. The sphericity (R1) and roughness (R2) parameters showed specific characteristics of the particles, suggesting long distance of their origin. Furthermore, an increase up to 4 times more in the At% of the elements K, Al, Ca, Na and Si, which characterize the felsic lava, was observed during the eruption period.

Volume X |

Observation of Unusual High Particulate Mass and Number Concentration during Traffic Ban Hours of the 2009 Car Free Sunday in the Brussels Urban Area

Abstract: Every year, since 2002, the Brussels authorities organize a car free day on the third Sunday of September. This very interesting experience has revealed some valuable information concerning traffic-related gaseous pollutants and particulates. On the car free Sunday of 2006 very high PM10 and PM2.5 mass concentrations were measured, along with very low concentrations for nitrogen oxides, carbon monoxide and dioxide. The car free Sunday of 2009 also showed very interesting results. During the traffic ban hours, particulate mass concentration and particulate number concentration peaked to one of the highest values for the whole year 2009. Black Carbon however was the only measured particulate component whose concentration continued to decrease during the traffic ban period.

Volume IX |

Particulate Matter and Nitrogen Dioxide in the Brussels Ambient Air. To What Extent Local Emission Reductions Need to Be Drastic to Enable Compliance with the EU Limit Values

Abstract: Over the past 40 years ambient air quality in Brussels improved significantly. This was especially true for sulfur dioxide, lead, nitrogen monoxide, carbon monoxide, benzene and Benzo a pyrene. With respect to the air quality objectives imposed by the most recent European directive on air quality, 2008/50/EC, two major problems remain: nitrogen dioxide (NO2) and particulates (PM10 and PM2.5). Although the air quality objectives are met at several measuring sites in Brussels, a thorough analysis of data shows that it will be impossible to become fully compliant, in due time, in all of the different urban environments. A comparison of the average concentration levels in the Brussels Capital Region with those in the surrounding regions, the interpretation of the average daily and weekly concentration profiles and some special observations (e.g. car free Sundays) make clear that drastic emission reductions will be needed if compliance is to be assured solely by measures on the local scale.

Volume IX |

Heavy Metals Identified in Airborne Particles During Weekend Periods in Brussels Urban Environment

Abstract: There has recently been growing interest in the study of atmospheric particulate matter, specifically towards improved understanding of the long-term transport and impact of different elements of the lithosphere on atmospheric pollution. Close to the ground level, a fairly thin layer of the lithosphere and atmosphere, on both sides of their interface, serves as the major platform for human life and activity. Both the lithosphere and the atmosphere are mutually responsible for sustaining their natural equilibrium.
Investigations related to the studies of atmospheric particulate matter are intended to provide information that is still required for the implementation and the eventual revision of European standard tolerance norms for environmental protection. To this aim, WHO (the World Health Organization) and the EU (European Union) Working Groups on airborne particles are requiring additional information in this field.
Airborne particles of heavy metals, especially in overdose, may harm population health in a long or a short term. Our objective in the present study is to describe and compare the presence of heavy metals in the Brussels atmosphere during three days periods including Saturdays, Sundays and Mondays and their possible effect on human health. The heavy metals were divided into three main groups for: “high dangerous elements” (Pb, Sb, Cd and As); “non dangerous and low dangerous elements” (Sn, Cu, Ti, Cs, Bi, Zr, W, Ag, V, Ni and Al) and “micro-elements” (Co, Zn, Mn, Mg and Cr).
This study has been carried out during the period extending from September 2002 up to October 2003.