GES air quality map — condition 2017

Area-covering map of Health Effects Screening score (GES) of local air quality in Flanders. The indicator is based on the annual average NO2 (nitrogen dioxide) concentrations (Flemish Environmental Society 2017), which was modelled with the RIO-IFDM-OSPM model chain. This polluent was taken as a basis for its large spatial variation, strong link with local emissions and well documented health effects. The concentrations of NO2 were then divided into classes, using the Dutch Health Effect Screening (GES) methodology, which provide an insight into potential health effects of air pollution by NO2, as the first indication of local air quality. Of course, other pollutants (e.g. particulate matter or ozone) are also important in the further analysis and assessment of local air quality. The GES classes were defined in this way: GES 1 = 0-10 µg/m³ annual mean NO2 = ‘good’; GES 4 = 10-20 µg/m³ annual mean NO2 = “moderate”; GES 6 = 20-30 µg/m³ annual mean NO2= ‘insufficient’, GES 7 = 30-40 µg/m³ annual mean NO2= ‘very insufficient’, GES 8 >40 µg/m³ annual mean NO2= ‘very insufficient’. From GES 6 onwards, the health advisory value as advised by the Agency for Health and Care (up to 20 µg/m³ annual mean NO2) is exceeded, but also lower concentrations have negative effects on health.