5.3- Number of Exceedences of Air Quality Limit Values
This state indicator shows how often the air pollution exceeds the (daily) limits. Increasing number of exceedences shows a decline in air quality.
Number of exceedances has been increasing over the years; one reason of this is the air quality limit values decreasing in cascades since 2009 as identified in the By-Law on Air Quality Assessment and Management (BAQAM). Besides the reality that the targeted improvement in air quality is not being achieved, two reasons to the increasing number of exceedences are: lowering of the limit values every year and increasing number of monitoring stations.
In 2016, daily limit value are: 80 μg/m3 for PM10 and 200 μg/m3 for SO2. Total exceedences in 2016 rise to 8581 for PM10 and 139 for SO2 .
Graph 25 is based on 123 stations with a value exceeding every three years in the period between 2014-2016. According to Graph 25, although both limit values were reduced by 11% in 2016 compared to 2015, there was a 22.4% increase in the number of overruns for the PM10 parameter and a 25.2% decrease in the overrun for the SO2 parameter.
GRAPH 25— AIR QUALITY LIMITS AND NUMBER OF EXCEEDANCES OVER THE YEARS
1. Exceedances are assessed by daily (24 hourly) average values of the measurement results.
2. The data for 123 stations, which are overvalued every three years between 2014 and 2016, are taken as basis.
3. Limit values were determined as: For PM10, 100 µg/m³ (2014), 90 µg/m³ (2015) and 80 µg/m³ (2016)
For SO2; 250 µg/m³ (2014), 225 µg/m³ (2015) and 200 µg/m³ (2016).