Summary results 2017

For some substances, however, targets are not yet met:

• The nitrogen dioxide concentrations exceeded the European limit value at 1 measuring station. Model calculations and local measurement campaigns show that the annual limit value is also exceeded at other locations with a lot of traffic;
• The long-term target for ozone was exceeded;
• The heavy metal concentrations for arsenic, cadmium and nickel were too high near a number of metal plants.

The table below assesses Flemish air quality in 2017 against European regulations. These limit or target values take into account not only health effects, but also technical feasibility and economic consequences of the concentration levels imposed by the regulations.
The numbers between brackets are the number of measuring stations that met the guideline value and the total number of measuring stations.

2008/50/EG limit value		average on the basis of				alert treshold	infor- mation treshold
		hour	8-hour	day	year
SO2 sulphur dioxide		(17/17)		(17/17)		(17/1)7
NO2 nitrogen oxide		51/51			(50/51)	(51/51)
PM10 particulate matter (fraction < 10 µm)				(36/36)	(36/36)
PM2,5 particulate matter (fraction < 2,5 µm)					(37/37)
CO carbon monoxide			(4/4)
Pb lead					(12/12)
benzene					(12/12)
2008/50/EG - Ozone		hour	8-hour	day	year
Health						(17/17)	(1/17)
Target value			(17/17)
Long-term target			(1/17)
Vegetation
Target value		(17/17)
Long-term target		(1/17)
2004/107/EG - target value		hour	8-hour	day	year
As arsenic					(9/12)
Cd cadmium					(11/12)
Ni nickel					(11/12)
B(a)P benzo(a)pyrene					(8/8))

World Health Organisation guideline values not yet within reach

When we assess the air quality in 2017 against the World Health Organisation (WHO) guideline values, we see that particulate matter, ozone and sulphur dioxide are particularly problematic. Compared with the guideline values:

Compared with these guideline values, the concentrations of:

• ozone is too high at all measuring stations;
• particular matter is too high at almost all measuring stations;
• sulphur dioxide is too high at more than half of the measuring stations;
• nitrogen dioxide and cadmium are too high at a few locations.

The table below assesses Flemish air quality in 2017 against the WHO guideline values.
The numbers between brackets are the number of measuring stations that met the guideline value and the total number of measuring stations.

2008/50/EG  limit value		average on the basis of
		hour	8-hour	day	year
WHO recommended value -   health
SO2 sulphur dioxide				(7/17)
NO2 nitrogen oxide		(51/51)			(50/51)
PM10 particulate matter (fraction < 10 µm)				(0/36)	(5/36)
PM2,5 particulate matter(fraction < 2,5 µm)				(0/37)	(0/37)
CO carbon monoxide			(4/4)
O3 ozone			(0/17)
Pb lead					(12/12)
Cd cadmium					(11/12)
Hg mercury					(2/2)
Mn manganese					(12/12)

These guideline values are not included in the Flemish legislation. Their sole purpose is to protect human health, so no consideration is given to economic consequences or technical feasibility. This explains why the WHO guidelines are often more stringent than the European standards. As a result, the concentrations of quite a number of pollutants exceeded these guideline values, although they amply met the regulations imposed by Europe.

Read the extended summary air quality 2017