Meetstation voor luchtverontreiniging Brasschaat: jaarverslag 2006

The measuring year 2006 was characterized by high ozone levels in the month July. A monthly average of 90 µg m-3 was measured, which had never been achieved before. The weather conditions in the subsequent months were not favourable to ozone formation (low temperatures and radiation) leading to substantial reductions in ozone levels. For sulphur dioxide, concentrations continue to decrease. External ozone index AOT40 reached, just like 1995 and 2003, high ozone exposure doses exceeding 15000 ppbhours. For sulphur dioxide the decreasing trend is continued. In 2006 the lowest levels since the start of the measurements, were noticed (7.1 µg m-3). Though pollution climate is still strongly liable to western winds bringing SO2-bearing air masses from the petrochemical industry located at Antwerp Left Scheldt Bank to the site in Brasschaat. Levels of NOx remained unchanged, since the measurements took off in 1995. Critical levels for acute or chronic exposure of plant vegetation to nitrogen oxides are still being largely exceeded.